The Pennsylvania State University

The Graduate School

College of the Liberal Arts

PROSOCIAL BEHAVIOR IN EARLY CHILDHOOD: THE CONTRIBUTIONS OF

PARENTAL EMOTIONAL EXPRESSIVENESS AND CHILDREN’S

PHYSIOLOGICAL REGULATION

A Thesis in

Psychology

by

Leigha A. MacNeill

© 2016 Leigha A. MacNeill

Submitted in Partial Fulfillment

of the Requirements

for the Degree of

Master of Science

May 2016

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The thesis of Leigha A. MacNeill was reviewed and approved* by the following:

Alysia Y. Blandon

Assistant Professor of Psychology

Thesis Adviser

Kristin A. Buss

Associate Professor of Psychology

Ginger A. Moore

Associate Professor of Psychology

Melvin M. Mark

Professor of Psychology

Head of the Department of Psychology

*Signatures are on file in the Graduate School.

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ABSTRACT

Prosocial development in early childhood plays an important role in children’s social

adjustment throughout the lifespan (Eisenberg, Fabes, & Spinrad, 2006). The family is a

proximal socialization context that teaches children about the emotional states of others and how

to respond to such states (Valiente, Eisenberg, Fabes, Shepard, Cumberland, & Losoya, 2004).

Emotional expressiveness, emotions that parents express in the presence of their children,

influences how their children respond in social events, such as ones that encourage prosocial

behavior (Eisenberg, Cumberland, & Spinrad, 1998). There is some research to suggest that

parents’ emotion socialization contributes to the physiological mechanisms that regulate

children’s social engagement (e.g., Hastings & De, 2008). It is important to address that

studying one parent and one child in the family does not fully capture children’s emotion

socialization environment, thus the current study examined whether the associations between

mothers’ and fathers’ emotional expressiveness and children’s prosocial behavior differed for

two children in the same family. Additionally, it examined if children’s baseline RSA moderated

the associations between parents’ emotional expressiveness and children’s prosocial behavior.

This study utilized data from a larger study of 70 families, including mothers, fathers, older

siblings, and younger siblings. The results indicated that higher levels of mothers’ positive

emotional expressiveness were associated with greater sharing. Further, significant interactions

between parental emotional expressiveness and sibling, as well as between parental emotional

expressiveness and baseline RSA, emerged. The results also indicated significant relations

between ratios of parents’ emotional expressions and children’s sharing. The current study

stresses the importance of examining emotion socialization and physiological regulation in the

development of prosocial behavior from a family systems perspective.

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TABLE OF CONTENTS

List of Tables……………………………………………………………………………………...v

List of Figures…………………………………………………………………………………….vi

Introduction………………………………………………………………………………………..1

Method…………………………………………………………………………………………...16

Results……………………………………………………………………………………………21

Discussion………………………………………………………………………………………..31

References………………………………………………………………………………………..43

Appendix A: Tables……………………………………………………………………………...54

Appendix B: Figures……………………………………………………………………………..63

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LIST OF TABLES

Table 1. Descriptive Statistics……………………………………………………………………54

Table 2. Correlations among Study Variables…………………………...………………………55

Table 3. Multilevel models examining mothers’ and fathers’ emotional expressiveness and

children’s baseline RSA as correlates of children’s helping behavior…………………………..59

Table 4. Multilevel models examining mothers’ and fathers’ emotional expressiveness and

children’s baseline RSA as correlates of children’s sharing behavior…………………………...60

Table 5: Multilevel models examining mothers’ and fathers’ ratios of emotional expressiveness

and children’s baseline RSA as correlates of children’s helping behavior………………………61

Table 6: Multilevel models examining mothers’ and fathers’ ratios of emotional expressiveness

and children’s baseline RSA as correlates of children’s sharing behavior………………………62

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LIST OF FIGURES

Figure 1. The interaction between mothers’ negative-dominant emotional expressiveness and

sibling predicting children’s sharing……………………………………………………………..63

Figure 2. The interaction between mothers’ negative-nondominant emotional expressiveness and

children’s baseline RSA predicting children’s sharing…………………………………………..64

Figure 3. The interaction between the ratio of mothers’ positive to negative-dominant emotional

expressiveness and sibling predicting children’s sharing………………………………………..65

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Introduction

Early prosocial behavior is an important contributor to how children form and maintain

positive relationships with others (Eisenberg, Fabes, & Spinrad, 2006; Eisenberg et al., 1996).

Prosocial behavior is generally defined as voluntary behavior intended to benefit another

individual, in ways that include helping, cooperation, sharing, comforting, and showing concern

for others. Children who engage in higher levels of prosocial behavior are often better liked by

their peers and are generally more socially competent (Denham, McKinley, Couchoud, & Holt,

1990; Hastings, Utendale, & Sullivan, 2007). In contrast, children who demonstrate less

prosocial behavior are more likely to be rejected by their peers and act aggressively and

antisocially (Denham et al., 1990; Eron & Huesmann, 1984).

The family is a proximal socialization context that provides an important foundation for

how children learn about the emotional states of others and how to engage in prosocial behavior

in response to these states (Valiente, Eisenberg, Fabes, Shepard, Cumberland, & Losoya, 2004).

Emotional expressiveness, the emotions that parents generally express in front of their children,

is associated with how children engage in social situations, such as circumstances that promote

prosocial behavior (Eisenberg, Cumberland, & Spinrad, 1998). Although research largely

focuses on maternal emotional expressiveness, fathers provide experiences for children that are

not the same as the experiences in the mother-child relationship (Cox & Paley, 1997). Thus,

including fathers allows for the opportunity to explore whether children respond differentially to

mothers’ and fathers’ parental socialization. Research has suggested that the degree to which

parents’ emotional expressiveness impacts children’s social and emotional development may be

due in part to children’s physiological regulation (Hastings, Nuselovici, Utendale, Coutya,

McShane, & Sullivan, 2008; Hastings & De, 2008). The current study therefore examined how

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two children within the same family differentially respond to parents’ emotional expressiveness,

and whether or not these associations with prosocial behavior differ depending on children’s

physiological regulation.

Prosocial Development across Early Childhood

Across toddlerhood and into early childhood, children’s prosocial behavior undergoes

considerable transformation (Eisenberg et al., 2006). Some research suggests that the occurrence

of prosocial behaviors increases as children get older (Eisenberg & Fabes, 1998). For instance,

across ages 2, 3, and 4, rates of mother-reported prosocial behaviors have been shown to increase

(Ensor, Spencer, & Hughes, 2011). However, there has been some work to suggest that

prosocial behavior becomes more selective as children get older, in that they begin drawing on

past experiences to determine with whom they want to engage prosocially. For instance, 4- and

5-year-old children are more likely than 3-year-old children to share with friends than with peers

that they dislike (Paulus & Moore, 2014).

The discrepancies in the development of prosocial behaviors across early childhood may

be in part due to researchers examining prosocial behavior as a composite of many behaviors,

despite evidence suggesting that different types of prosocial behavior have unique developmental

trajectories (Dunfield, Kuhlmeir, O’Connell, & Kelley, 2011; Brownell, Svetlova, Anderson,

Nichols, & Drummond, 2013; Dunn & Munn, 1986; Bryant & Crockenberg, 1980). Prosocial

behaviors can be differentiated by the individual needs to which a person is responding (Dunfield

et al., 2011). Helping and sharing behaviors are two key types of prosocial behavior that show

up early in childhood, yet have different underlying response needs and progress at different

rates across development (Radke-Yarrow, Zahn-Waxler, & Chapman, 1983; Dunfield et al.,

2011). For instance, helping behaviors involve the ability to decipher the instrumental need of

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another by recognizing the other’s difficulty completing an action and knowing a possible

solution to the problem. On the other hand, for an individual to engage in sharing behavior, they

must be able to interpret that an inequality exists between them and the other person and

additionally be willing to sacrifice a resource to satisfy the problem (Dunfield et al., 2011).

Research suggests that engaging in sharing behaviors requires greater emotional and cognitive

development on the part of the benefactor, such that giving up one’s own material item is more

costly to younger children and requires a more developed other-orientation (Yarrow et al., 1976;

Eisenberg-Berg & Hand, 1979).

The intention to help another individual is one of the earliest developing prosocial

behaviors (Warneken & Tomasello, 2006). Children have been found to engage in helping

behaviors, such as handing over objects that another individual has expressed interest in, as early

as 14 months old (Warneken & Tomasello, 2007). In the toddler years, children have been

shown to use pointing in order to direct an adult’s attention to an item that they dropped

(Liszkowski, Carpenter, Striano, & Tomasello, 2006). In addition to helping others retrieve

objects, young children may assist others in achieving their social goals. When noticing an

experimenter trying to capture the attention of another individual, 3-year-old children were able

to engage in social helping by assisting the experimenter in their attention-seeking actions (Beier,

Over, & Carpenter, 2014). Research has suggested that although the reasoning behind helping

behavior may change across development (e.g., it was required, self-initiated, imitation, in

anticipation of reward; Bar-Tal, Raviv, & Leiser, 1980), the frequency of helping behaviors does

not significantly increase between 18 and 76 months of age (Bar-Tal, Raviv, & Goldberg, 1982).

Sharing behavior is generally defined as behavior meant to assuage another individual’s

material need (Dunfield et al., 2011). Between 12 and 18 months of age, children have been

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observed to spontaneously share their food and toys within a short amount of time on several

occasions, regardless of the recipient (e.g., mother, father, unfamiliar person) and the behavior

demonstrated by the recipient (Rheingold, Hay, & West 1976). Relative to 1-year-old children,

at 24 months, children are more inclined to share their toys because they desire to, rather than

because they had been pressured by other individuals to do so (Hay, Caplan, Castle, & Stimson,

1991). However, sharing can still be difficult even throughout preschool and typically occurs

less often than helping and cooperative behaviors (Eisenberg, 2005). For instance, 3 year olds

have been found to share equally with people who were potentially able to reciprocate sharing, as

well as with those who were unable to share. Meanwhile, 5 year olds were more likely to share

with others they knew had the potential to reciprocate sharing (Sebastián-Enesco & Warneken,

2015). In a study of 3- to 5-year-old children, when asked to share stickers with another

individual, there was no difference across age in sharing when the child was told they could get

one sticker right away or the child and the experimenter could each get a sticker right away.

However, when children were told that they could have one sticker for themselves now or that

both the child and other experimenter could get one sticker later, 3 year olds were significantly

different from the 4-and 5-year-old children, in that they were more likely to take the immediate

gratification option (Thompson, Barresi, & Moore, 1997). These results suggest that there are

age-related differences in future-oriented sharing behaviors that emerge at 4 years of age,

requiring a more developed cognitive capacity to understand and take into consideration the

wants of others.

Parental Emotional Expressiveness and Children’s Prosocial Behavior

The early development of children’s helping and sharing behaviors is associated with

children’s socialization experiences (Brownell et al., 2013; Yarrow et al., 1976; Hastings et al.,

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2007; Knafo & Plomin, 2006). Parents socialize their children’s emotions in a myriad of ways,

all of which can impact children’s prosocial behavior. While some emotion socialization efforts

are in direct response to the child (e.g., parent comforts child when he is crying), other

socialization strategies are indirect. One key aspect of parents’ indirect emotion socialization is

their emotional expressiveness. Parental emotional expressiveness is defined as the emotions

that parents generally express in the family context, but it does not necessarily pertain to

situations involving the child, nor is the emotion child-directed (Eisenberg et al., 2001).

Parents’ consistent patterns of verbal and nonverbal emotional expressions contribute to

the emotional climate in the family (Eisenberg et al., 1998). It has been argued that the

emotional climate of the family relates to how children appraise and engage in emotional

situations within the family context and other social settings (Halberstadt, Cassidy, Stifter, Parke,

& Fox, 1995; Eisenberg, et al., 1998). Specifically, how often parents express emotions and

what emotions they express given the situation foster children’s emotional understanding and

teach children how they are expected to respond during emotionally salient events. Children’s

emotional understanding is thought to be an important contributor to the development of

children’s prosocial behavior (Ensor et al., 2011; Eisenberg, 2000). More specifically, the ability

to infer the emotional states and needs of others better enables an individual to quickly respond

to those situations in prosocial ways (Iannotti, 1985).

A family context characterized by positive emotional expressiveness may matter for

children’s development of prosocial behavior. Positive expressiveness includes displays of joy,

enthusiasm, delight, and pleasant surprise, and their positive associations with children’s social

adjustment have been clearly established in the literature (Eisenberg et al., 1998). When the

broader emotional climate that parents provide is more positive, children feel less self-concern

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and are more likely to respond to the emotions of others (Janssens & Gerris, 1992). Research

has found that higher levels of positive parental expressiveness were related to higher levels of

kindergarten children’s prosocial behaviors including helping, sharing, and taking turns (Boyum

& Parke, 1995). Mothers’ positive emotional expressiveness has been associated with preschool

children’s prosocial caregiving behavior toward a younger sibling (Garner, Jones, & Miner,

1994), and children whose mothers express more positive emotion have shown greater levels of

self-reported empathy and empathic facial expressions (Zhou et al., 2002). More broadly,

research has found a link between parents’ positive expressiveness and children’s greater social

competence when engaging with peers (MacDonald & Parke, 1984). These findings demonstrate

that parents who express more positive emotions in the family afford children greater social

competence and the necessary skills for engaging with others in prosocial ways.

Parents’ negative emotional expressiveness, on the other hand, may hinder children’s

development of prosocial behaviors. Negative emotional expressiveness is generally

characterized by manifestations of anger, sadness, and anxiety. Heightened exposure to negative

emotional expressiveness has been found to increase children’s distress and harm their

attentional capacities, where they have difficulties learning strategies for appropriately dealing

with their emotionally driven behavior. These difficulties children experience, in turn, limit their

levels of other-oriented behavior (Eisenberg & Fabes, 1998; Eisenberg et al., 2001). Parents’

negative emotional expressiveness has also been found to contribute to heightened emotional

arousal in children, restricting how much attention they can give to the needs of others

(Hoffman, 1977). One study found that preschoolers and kindergartners with lower levels of

prosocial behavior were more likely to have parents who expressed greater observed levels of

spontaneous negative affective expressions (Boyum & Parke, 1995; Denham & Grout, 1992).

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Even after controlling for children’s levels of negative affect, parents’ negative expressiveness

has been associated with deficits in teacher-rated social competence, which includes verbal

aggression, physical aggression, and disruptive behaviors, as well as lower levels of prosocial

behaviors (Isley, O’Neil, Clatfelter, & Parke, 1999).

It is important to note that negative emotions are a normal part of daily life, therefore,

some parental expression of negative emotion that is not high-intensity or long-lasting may help

children learn about situations involving negative emotions (Valiente et al., 2004). For instance,

mothers’ low-intensity anger, as well as anger unrelated to children’s disobedience, have been

linked to preschoolers’ greater overall prosocial behavior in reaction to their peers’ emotions in

the classroom (Denham & Grout, 1992). Additionally, the clarity of mothers’ negative

emotional expressiveness has been found to be the best predictor of girls’ helping and sharing

behaviors (Boyum & Parke, 1995). Parents who demonstrate clear expressions of negative affect

may assist their children in regulating their negative expression, which in turn, allows them to

more adaptively affiliate with their peers.

The type of negative emotion expressed may also influence its relation to child outcomes,

and the literature has so far differentiated between dominant and nondominant types of negative

emotional expressiveness (Eisenberg et al., 1998). The negative-dominant type is characterized

by hostile and assertive verbal and nonverbal expressions that are often associated with the

emotion of anger, while the nondominant type is comprised of more submissive negative

expressions that have been associated with the emotions of sadness or worry. Generally, more

dominant negative emotions have been related to children’s displays of negative emotions, while

more submissive forms have been unrelated to children’s negative emotional expressions

(Eisenberg et al., 1998; Halberstadt, 1986). Parental dominant, negative expressiveness has been

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linked to 55- to 79-month-old children’s lower social competence as mediated by children’s

effortful control (Eisenberg et al., 2001). One study examining children’s emotion regulation in

response to an undesired gift found that mothers who used more dominant negative

expressiveness had children who had more difficulties regulating their negative emotional

responding (Garner & Power, 1996). Submissive negative emotional expressiveness in this

study, however, was not associated with children’s regulation or social competence. One study

found that parents’ submissive negative expressions, such as sadness, fear, and pain, were related

to higher levels of sympathy in toddlers (Crockenberg, 1985). These findings suggest that more

harsh negative emotions, as opposed to all negative emotions, may deleteriously impact

children’s social adjustment. Children who experience a more negative-dominant emotional

climate may be more likely to demonstrate negative expressions themselves, limiting their

abilities and opportunities for engagement in prosocial behaviors. Although there is a dearth of

literature on these two types of negative emotional expressiveness, the available research

underscores the need to examine constructs beyond the more simplistic dimensions of positive

and negative expressiveness.

The literature has often conceptualized an individual’s emotional expression on a

continuum from negative to positive, but it should not be assumed that a parent who is high in

positive emotional expressiveness is necessarily low in negative emotional expressiveness, or

vice versa (Diener, Larsen, Levine, & Emmons, 1985). Thus, the relative proportions of parents’

emotional expressiveness in the home may matter for the development of children’s prosocial

behavior. Some work has acknowledged that distinct patterns of emotional expressiveness

emerge for parents, categorizing them as high positive and low negative, very low positive and

average negative, or average positive and very high negative expressiveness. This work has also

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found links to children’s emotional development, where higher levels of positive expression

accompanied by low levels of negative expression have been associated with less child-displayed

negative affect and use of more positive emotion words with others (Nelson, O’Brien, Calkins,

Leerkes, Marcovitch, & Blankson, 2012). In addition, parents characterized by higher levels of

negative emotional expression when compared to their positive emotional expression had less

socially-competent preschool children (Denham, Mitchell-Copeland, Strandberg, Auerbach, &

Blair, 1997). Elucidating the relative contributions of each parent’s emotional expressiveness to

the family climate may help to resolve discrepancies related to how much negative affect

exposure is considered optimal for prosocial development with respect to how much positive

emotion is being expressed. The current study is the first to explore how ratios of parents’

emotional expressiveness, that include the two subtypes of negative emotional expressiveness

(i.e., negative-dominant and negative-nondominant), contribute to young children’s emerging

prosocial behavior.

Research has primarily focused on the links between mothers’ positive and negative

emotional expressiveness and children’s socioemotional development. Family systems theory

conceptualizes the family as a complex system composed of multiple subsystems (Cox & Paley,

1997), and the focus on one parent and one child in the family provides limited information

regarding the socialization influences children experience (e.g., Feinberg & Hetherington, 2001).

The mother-child dyad alone cannot depict a full understanding of how children are impacted by

parental socialization, so we need to consider both parents to comprehend how the parent-child

subsystem is associated with prosocial behavior in children. Further, the associations between

parental emotional expressiveness and children’s social and emotional development are different

for maternal and paternal expressiveness (Lamb & Lewis, 2010; Cassidy, Parke, Butkovsky, &

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Braungart, 1992). For instance, it has been shown that fathers’ positive affect, and not mothers’,

was associated with kindergarteners’ helping and sharing behaviors, while mothers’ positive

expressiveness was related to greater overall sociometric ratings for girls (Boyum & Parke,

1995). Some research has suggested that males in general show less recognizable facial

expressions than their female counterparts (Brody, 1985). When placed in the parenting context,

children have found it more difficult to read fathers’ emotional expressions over their mothers’,

even though children’s greater general emotion recognition skill of basic emotional expressions

(i.e., happiness, sadness, fear, and anger) has been related to fathers’, and not mothers’,

emotional expressions (Dunsmore, Her, Halberstadt, & Perez-Rivera, 2009). These findings

suggest that although mothers may be more skilled at communicating their emotions, fathers’

emotional expressions, when communicated clearly, may be more salient to children in their

development of emotional understanding. Arguably, both parents may facilitate children’s

abilities to interpret and respond to a variety of different emotional contexts, which are skills that

are necessary for the development of prosocial behavior. Although there is some work

delineating the differences between mothers’ and fathers’ emotional expressiveness in shaping

children’s social adjustment, these effects have yet to be studied in relation to how different

children in the same family engage in prosocial behaviors specifically.

Another assumption of studies that only include one parent in the family is that the

influence of parental expressiveness is the same for multiple children in the same family. Sibling

differences in prosocial behavior, however, are likely affected by the differential effects of

parents’ emotion socialization. Parental socialization strategies have been found to have a

greater influence on children across childhood, which can be partially attributed to the

acquisition of greater emotional competence and cognitive ability that allow children to better

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understand the reasoning behind parents’ behaviors (Grusec & Goodnow, 1994). However,

sibling differences in prosocial behavior are likely due to factors apart from age. For instance,

one study found that mothers and fathers report differential levels of negative affect toward

siblings within the same family, and the sibling to whom more negative affect was expressed

experienced more social adjustment problems (Deater-Deckard, 1996). However, this literature

has primarily focused on differential treatment and has yet to study how mothers’ and fathers’

general emotional expressiveness uniquely impact the prosocial behavior of multiple children

within the family. One of the goals of the current study was to elucidate the within-family

variability of mothers’ and fathers’ emotional expressiveness and their differential associations

with older and younger siblings who are at different stages in their development of prosocial

behavior.

The Role of Physiological Regulation in Children’s Prosocial Behavior

Responding prosocially to others is dependent upon an individual’s dispositional ability

to self-regulate (Porges & Furman, 2011). Those individuals who have difficulties self-

regulating are more likely to experience protracted stress responses to demanding situations,

which for some young children may be interacting with unfamiliar individuals or being prosocial

toward a sibling. This difficulty to regulate can then impede children’s capabilities to access

adaptive coping strategies that would allow them to engage positively in social interactions

(Calkins & Fox, 2002). Therefore, individual differences in prosocial tendencies may be

partially explained by one’s trait physiological regulation. Porges’ polyvagal theory proposes

that the functioning of the parasympathetic nervous system is an important aspect of

physiological regulation, where the vagal system facilitates flexibility in responding to

environmental challenges through variability in heart rate, or respiratory sinus arrhythmia (RSA;

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Porges, 2007). When vagal tone is engaged, it allows an individual to maintain a lower heart rate

and thus interact with others in adaptive and prosocial ways. This system orients the individual

toward the facial expressions and vocal signs of emotion of another conspecific, allowing that

individual to respond in reflexive and adaptive ways in the social situation, and more precisely,

to engage in behaviors intended to promote social affiliation and friendship. Individuals with

greater vagal regulation have an increased likelihood to behave in socially skilled and prosocial

ways.

Baseline RSA, measured under conditions of little environmental demand, is often

considered a physiological marker of the individual’s dispositional ability to self-regulate

(Porges, 2007). In studies done with adults, individuals with higher levels of baseline RSA had

increased levels of positive emotions and feelings of social connectedness (Kok & Fredrickson,

2010; Kok et al., 2013). In young children, high resting RSA has been linked to more

appropriate emotional reactivity (Stifter & Fox, 1990). 8- to 12-year-old children with lower

baseline RSA have been found to have more emotional and behavioral problems (Hinnant & El-

Sheikh, 2009). Children who regulate their arousal states effectively have more of the

physiological resources necessary for engaging in positive relationships with others, as well as

responding to the distress of others. However, an individual with dispositional low baseline

RSA will most likely have a more highly engaged defensive system, hampering that individual’s

ability to engage in other-oriented behavior and opportunities for social bonding (Porges &

Furman, 2011).

How a child’s physiological regulation impacts the associations between parental

emotion socialization and children’s prosocial behavior may additionally be influenced by the

age of the child. Baseline RSA has been shown to increase during the period between 2 months

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and 5 years of age, suggesting that, as children get older, their physiological capacity to regulate

is improving (Bornstein & Suess, 2000; Porges, Doussard-Roosevelt, Portales, & Suess, 1994).

These increases in baseline RSA suggest that the myelination of the vagal fibers throughout the

time period lend to heightened hierarchical organization of one’s physiological systems to

promote more stable self-regulation. Still, individual differences in baseline RSA often maintain

rank order differences across the first few years of life (Porges et al.,1994; Bar-Heim, Marshall,

& Fox, 2000). Therefore, by early childhood, an individual’s typical level of arousal can be

viewed as a protective factor against, or risk factor for, social adjustment problems (Hastings &

De, 2008), and potentially for children’s difficulties engaging in prosocial behavior.

Parents’ emotional expressiveness may differentially relate to children’s abilities to

engage in prosocial behavior depending on the child’s physiological regulation levels.

Children’s baseline RSA has been found to moderate the relation between marital conflict and

children’s social adjustment, suggesting that higher baseline RSA can buffer children from the

detrimental effects of a negative emotional climate on children’s socioemotional outcomes (El-

Sheikh, Harger, & Whitson, 2001). For preschoolers with lower baseline RSA, the effects of

direct parental socialization on externalizing and internalizing problems were stronger than for

those children with higher levels of baseline RSA, demonstrating that children with low baseline

RSA may be more vulnerable to the effects of parents’ socialization efforts (Hastings & De,

2008).

This research on vagal regulation as a process that moderates parental socialization and

children’s outcomes has primarily relied on the negative consequences of maladaptive

socialization. Yet, hardly any research exists on the positive emotions and behaviors (e.g.,

prosocial behavior) that children may demonstrate that are associated with parents’ emotional

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expressiveness, and whether these differences are contingent upon children’s levels of

physiological regulation. The role of physiological regulation in the relation between parental

emotional expressiveness and children’s prosocial behavior may differ depending on whether the

socializer is the mother or father. While most of the current literature examines mothers, the

limited research on fathers has suggested that fathers are uniquely related to children’s social

functioning. For instance, when fathers responded to children’s fear and sadness with warm and

comforting behaviors, children with lower baseline RSA were more socially competent, and this

interaction was not significant for mothers (Hastings & De, 2008). Although research has yet to

investigate emotional expressiveness, and specifically the subtypes of emotional expressiveness

dimensions (i.e., positive, negative-dominant, negative-nondominant expressiveness), it is

expected that the types of emotions mothers and fathers express within the family context are

differentially associated with children’s prosocial behavior, dependent upon children’s

physiological regulation. Finally, the effects of parental emotional expressiveness and children’s

physiological regulation on children’s prosocial behavior may differ for older and younger

siblings. Young children’s prosocial behavior develops within the context of the family, and

individual differences in physiological regulation may heighten or dampen the effects of parental

emotional expressiveness on these differences in prosocial behavior development.

The Current Study

The current study investigated whether children’s physiological regulation moderated the

association between parents’ emotional expressiveness and children’s prosocial behavior, and

whether these effects differed for older and younger siblings in the family. By utilizing a family

systems perspective, this study examined how different children in the same family uniquely

responded to parental emotional expressiveness, as previous research has suggested that parents’

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general socialization efforts impact within-family variability of children’s prosocial behavior

(Brody, Stoneman, & Burke, 1987; Dunn & Munn, 1986). The current study examined four

aims.

Aim 1: Assessed if there were differences in the levels of mothers’ and fathers’

emotional expressiveness. It was hypothesized that, given the existing literature, mothers would

express higher levels of positive emotion.

Aim 2: Examined whether mothers’ and fathers’ emotional expressiveness were

associated with children’s prosocial behavior. It was hypothesized that parents who expressed

more positive emotions, as well as more positive emotions relative to their negative-dominant

emotions, would be more likely to have children with higher levels of prosocial behavior.

Additionally, it was predicted that there would be a positive relation between negative-

nondominant emotional expression and children’s prosocial behavior. It was also predicted that

parents’ expressions of negative-dominant emotions, as well as greater negative-dominant

emotions relative to negative-nondominant emotions, would be inversely related to children’s

prosocial behavior.

Aim 2a: Explored whether the associations between mothers’ and fathers’ emotional

expressiveness and children’s prosocial behavior differed for older and younger siblings. Due to

the lack of research on within-family differences in prosocial behavior in the context of parental

emotional expressiveness, the differential associations with older and younger siblings’ prosocial

behavior were exploratory.

Aim 3: Examined whether children’s baseline RSA was associated with their prosocial

behavior. It was hypothesized that higher levels of children’s baseline RSA would be related to

higher levels of prosocial behavior in children.

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Aim 3a: Explored whether the association between children’s baseline RSA and their

prosocial behavior differed for older and younger siblings. Because of the lack of research on

within-family variability in prosocial behavior as associated with baseline RSA, these relations

were exploratory.

Aim 4: Examined if children’s baseline RSA moderated the relations between mothers’

and fathers’ emotional expressiveness and children’s prosocial behavior. It was hypothesized

that children with lower levels of baseline RSA would be more susceptible to the effects of both

positive and negative emotional expressiveness demonstrated by the parents, which would

impact their prosocial tendencies. For instance, lower RSA would act as a vulnerability factor

exacerbating the influence of negative-dominant parental emotional expressiveness, or less

positive emotional expressiveness relative to negative-dominant emotional expressiveness, on

children’s prosocial behaviors. Children who come from homes with higher negative-dominant

expressiveness and who have lower baseline RSA could be more reactive to the negative

emotional climate and thus find it more difficult to be prosocial toward others. Alternatively,

higher parental positive emotional expressiveness and negative-nondominant expressiveness

relative to their negative-dominant emotional expressiveness, in conjunction with lower baseline

RSA, could be protective in terms of demonstrating greater levels of prosocial behavior.

Aim 4a: Explored whether these associations differed for older and younger siblings.

Due to the dearth of research on emotional expressiveness and child RSA within the context of

the family system, the differential associations with older and younger siblings’ prosocial

behavior were exploratory.

Method

Participants

17

Mothers, fathers, and their two children participated in a study that investigated

children’s social and emotional development within the context of the family (N = 70 families).

In order to participate in the study, parents had to be married or cohabitating (N = 3) and have

two children between the ages of 2 and 5 years. Newspaper birth announcements, flyers posted

at daycares, and a database of local families who have interest in participating in research studies

were used for recruitment. Mothers were 32 years old on average (SD = 4.15 years) and 55.7%

of them were employed. Fathers were on average 34 years old (SD = 4.15 years) and 94.3% of

them were employed. The sample was primarily Caucasian (fathers: 92.9% Caucasian, 4.3%

Hispanic/Latino, and 2.9% Other; mothers: 90% Caucasian, 7.1% Hispanic/Latino, 1.4% Asian

American, and 1.4% Other). The older sibling (OS) was on average 57.6 months old (SD = 7.58

months; Range = 37.50 – 74.10 months) and the younger sibling (YS) was on average 32.6

months (SD = 6.98 months; Range = 23.90 – 58.70). The average household size was 5 family

members (Range = 4 – 8), and the median family income was $70,000 (Range = $10,000 –

$250,000). There were 17 girl/girl dyads, 21 boy/boy dyads, 15 older boy/younger girl, dyads

and 17 older girl/younger boy dyads.

Procedure

Families participated in a 2.5-hour laboratory visit that included tasks not mentioned in

the current thesis. Parents completed informed consent procedures, after which electrodes for

cardiac data recording were placed on all four family members. Cardiac data were collected over

the 5-minute baseline session, during which all four family members sat quietly on the couch.

Prosocial behaviors were coded from a 7-minute videotaped sibling interaction task. During this

task, children were instructed to take turns using a plastic screwdriver to put bolts in a board to

make a design, and they were given only one screwdriver so they had to work together. The

18

experimenter and the parents were not in the room during the task. Parents completed

questionnaires throughout the visit and any unfinished questionnaires were sent home with them

to send back to the lab at their convenience. The Institutional Review Board approved this study.

Measures

Parental emotional expressiveness. Mothers (M) and fathers (F) completed the Self-

Expressiveness in the Family Questionnaire (SEFQ; Halberstadt et al., 1995). This 40-item scale

included two subscales that measure adults’ positive and negative verbal and nonverbal

emotional expressiveness within a family setting. Each item was scored on a scale from 1 to 9 (1

= not at all to 9 = very frequently). The positive expressiveness subscale included 20 items such

as, “expressing excitement for one’s future plans” and “expressing deep affection of love for

someone.” The literature suggests that hostile negative emotions and submissive negative

emotions may have different implications for multiple aspects of social adjustment, thus the

negative emotional expressiveness items were categorized into two subscales, according to the

recommendations of Halberstadt (1986). The negative-dominant expressiveness subscale

included 10 items that assess the dominant, typically anger-related aspects of negative emotional

expressiveness. Example items include, “expressing dissatisfaction with someone else’s

behavior” and “quarreling with a family member.” The negative-nondominant expressiveness

subscale included 10 items that demonstrate the more submissive aspects of negative

expressiveness. Example items include, “telling a family member how hurt you are” and

“apologizing for being late.” The positive (M α = .90; F α = .80), negative-dominant (M α = .76;

F α = .86), and negative-nondominant (M α = .80; F α = .75) subscales were found to be reliable

for both mothers and fathers. Mean scores for each of the emotional expressiveness subscales

19

were calculated separately for mothers and fathers. Higher scores indicated greater emotional

expressiveness.

Ratios of each parent’s emotional expressiveness were also calculated by dividing one

type of emotional expression by another type of emotional expression. Thus, mothers and

fathers each had three ratio scores: positive to negative-dominant, positive to negative-

nondominant, and negative-dominant to negative nondominant emotional expressiveness.

Higher scores on the positive to negative-dominant ratio of emotional expressiveness indicated

greater positive relative to negative-dominant emotional expressiveness. Higher scores on the

positive to negative-nondominant ratio of emotional expressiveness indicated greater positive

relative to negative-nondominant emotional expressiveness. Lastly, higher scores on the

negative-dominant to negative-nondominant ratio of emotional expressiveness indicated greater

negative-dominant relative to negative-nondominant emotional expressiveness.

Physiological regulation. To collect cardiac data, three disposable pregelled spot

electrodes were placed on the children’s torsos. The electrocardiograph (ECG) signal was

acquired with Mindware Technologies LTD ambulatory Impedance Cardiographs (MW1000a)

using the WiFi ACQ software, Version 3.0.1 (Gahanna, OH). The ECG signal was sampled at

500 Hz and the ECG time series was transmitted wirelessly to a computer for offline processing.

The Mindware HRV analysis program (Version 3.0.17) was used to process the data. First, the

interbeat intervals (IBIs) were identified. Second, physiologically improbable intervals were

detected based on the overall IBI distribution using a validated algorithm (Berntson, Quigley,

Jang, & Boysen, 1990). A team of editors then visually inspected the data to identify artifacts

and erroneous or missing beats, which were manually corrected. Next, data were detrended

using a first-order polynomial to remove the mean and any linear trends, then cosine tapered, and

20

submitted to Fast Fourier Transform (FFT). Finally, RSA was defined as the natural log integral

of the .24 to 1.04 Hz power band and calculated in 30s epochs. Inter-editor reliability (RSA

values obtained by coders that fell within 0.10) was calculated for 20% of the cases, and coders

achieved 88% agreement for older siblings and 90% for younger siblings. Missing data were due

to technical problems (OS = 7; YS = 8), data that were too messy to edit (OS = 3), crying or

extremely fussy behavior (YS = 1), and because children refused to wear the electrodes (OS = 1;

YS = 3).

Prosocial behavior. Children’s prosocial behaviors were coded from the videotaped

sibling interaction task (M task length = 6.4 min, Range = 2.77 – 7.53 min). The frequencies of

four different types of prosocial behavior were coded. Sharing captured children giving away or

allowing temporary use of an object that was previously in the child’s possession (e.g., the older

sibling hands the screwdriver to the younger sibling). Helping behavior captured explanations or

physical aid, or attempts to alleviate another’s non-emotional needs (e.g., the older sibling tells

the younger sibling how to make the screwdriver work). Comforting behavior was coded when

one sibling demonstrated verbal or physical consolation when the other sibling was distressed

(e.g., the older sibling puts their arm around the younger sibling). Sharing, helping, and

comforting behaviors were coded separately for each sibling. Cooperation was a dyadic code

that captured when children engaged in a behavior that required both individuals (e.g., younger

siblings puts bolts in the board and the older sibling uses the screwdriver to screw in a bolt). The

current study focused on sharing and helping behavior to capture individual prosocial behavior.

Comforting behavior was not examined because it occurred very infrequently (OS M frequency

= 0.09%; YS M frequency = 0%), and cooperation was not examined because it was coded per

dyad. Inter-rater reliability was calculated on 20% of the cases for both the older and younger

21

sibling. Inter-rater agreement was 85.5% (κ = .92) for older siblings and 92.5% (κ = .97) for

younger siblings.

Because the duration of the sibling interaction task varied for each family, the proportion

of helping and sharing was calculated. The frequencies of helping and sharing were divided by

the duration of the task, and that proportion was converted back to a standard frequency by

multiplying each proportion score by the maximum task length. Higher scores indicated higher

frequency of that behavior occurring.

Results

The preliminary analyses are presented first, including missing data analyses and

descriptive statistics. Following are the multilevel models that examined the within-family

correlates of children’s helping and sharing behaviors, as well as the associations between

mothers’ and fathers’ emotional expressiveness and children’s prosocial behavior.

Missing Data. The percentages of missing data in the questionnaires were 16.8% and

10.9% for mothers and fathers, respectively. The percentage of missing data for the sibling

interaction task was 17%. Multiple imputation (N = 75 imputations) was performed in Mplus 7.3

(Asparouhov & Muthén, 2010; Muthén & Muthén, 1998-2012). All analyses were conducted

using the imputed data.

Preliminary Analyses. Mothers’ and fathers’ emotional expressiveness, older and

younger siblings’ baseline RSA, and older and younger siblings’ prosocial behavior were

examined for distribution normality and skewness. Due to the high positive skewness of both the

older and younger siblings’ helping and sharing behavior, the outcome variables were recoded.

Both older and younger siblings’ helping behavior was dichotomized, such that 0 = child

demonstrated no helping behavior during the task, and 1 = child showed one or more helping

22

behaviors during the task. Older and younger siblings’ sharing behavior was recoded on a scale

from 0 to 5, as there was greater variability in the frequency of sharing than there was in the

frequency of helping. 0 = child demonstrated no sharing behavior, and 5 = child demonstrated 5

or more acts of sharing.

The means and standard deviations for the study variables are presented in Table 1 and

the correlations are presented in Table 2. There was a positive cross-sibling correlation of

helping behavior, but no significant cross-sibling correlation of sharing behavior. The cross-

sibling correlation of baseline RSA was significant, where older siblings’ sharing was positively

correlated with younger siblings’ baseline RSA.

For older siblings, their baseline RSA was positively correlated with mothers’ positive

emotional expressiveness. Older sibling sharing was positively correlated with mothers’ positive

emotional expressiveness and negatively correlated with mothers’ negative-dominant emotional

expressiveness. Older siblings’ sharing was positively correlated with the ratio of mothers’

positive to their negative-dominant emotional expressiveness. Additionally, older siblings’

sharing was negatively correlated with the ratio of mothers’ negative-dominant to their negative-

nondominant emotional expressiveness. No older sibling variables were correlated with any

father variables.

For younger siblings, their baseline RSA was positively correlated with mothers’

negative-nondominant emotional expressiveness. Younger siblings’ sharing was negatively

correlated with the ratio of mothers’ negative-dominant to negative-nondominant emotional

expressiveness. No younger sibling variables were correlated with any father variables.

The positive cross-parent correlation of positive emotional expressiveness was

significant. Cross-parent correlations of negative-dominant, negative-nondominant, and the

23

ratios of emotional expressiveness were not significant.

Mothers’ positive emotional expressiveness was positively correlated with their negative-

nondominant emotional expressiveness and their ratio of positive to negative-dominant

emotional expressiveness. Additionally, their positive emotional expressiveness was negatively

correlated with their ratio of negative-dominant to negative-nondominant emotional

expressiveness. Mothers’ negative-dominant and negative-nondominant emotional

expressiveness were strongly positively correlated. Mothers’ negative-dominant emotional

expressiveness was also strongly negatively correlated with their ratio of positive to negative-

dominant emotional expressiveness, as well as their ratio of positive to negative-nondominant

emotional expressiveness. There was a negative correlation between mothers’ negative-

nondominant emotional expressiveness and their ratio of positive to negative-dominant

emotional expressiveness. Additionally, it was strongly negatively correlated with their ratio of

positive to negative-nondominant emotional expressiveness and their ratio of negative-dominant

to negative-nondominant emotional expressiveness. The ratio of mothers’ positive to negative-

dominant emotional expressiveness was strongly positively correlated with their ratio of positive

to negative-nondominant emotional expressiveness, and negatively correlated with their ratio of

negative-dominant to negative-nondominant emotional expressiveness. Mothers’ ratio of

positive to negative-nondominant emotional expressiveness was strongly positively correlated

with their ratio of negative-dominant to negative-nondominant emotional expressiveness.

Fathers’ negative-nondominant emotional expressiveness was strongly positively

correlated with their own positive and negative-dominant emotional expressiveness. The ratio of

their positive to negative-dominant emotional expressiveness was strongly positively correlated

with their positive expressiveness and strongly negatively correlated with their negative-

24

dominant expressiveness. The ratio of fathers’ positive to negative-nondominant emotional

expressiveness was strongly negatively correlated with both their negative-dominant and

negative-nondominant expressiveness. Finally, their ratio of negative-dominant to negative-

nondominant emotional expressiveness was strongly negatively correlated with their positive

expressiveness and their ratio of positive to negative-dominant expressiveness. Additionally, it

was positively correlated with their dominant expressiveness and negatively correlated with their

negative-nondominant expressiveness.

Differences between mothers’ and fathers’ emotional expressiveness. To address aim

1, I examined whether there were differences in emotional expressiveness for mothers and

fathers. Paired t-tests were conducted and revealed that there was a significant difference in

mothers’ (M = 6.77, SD = 1.06) and fathers’ (M = 6.31 SD = 1.19) positive expressiveness, t = -

3.86, p < .001. There was no significant difference between mothers’ (M = 3.13, SD = 1.0) and

fathers’ (M = 3.34, SD = 1.13) negative-dominant emotional expressiveness, t = 1.54, p = .12,

nor a difference between mothers’ (M = 4.09, SD = 1.36) and fathers’ (M = 3.99, SD = 1.14)

negative-nondominant emotional expressiveness, t = -1.45, p = .15. The difference between

mothers’ (M = 2.40 SD = .90) and fathers’ (M = 2.16 SD = 1.05) ratios of positive to negative-

dominant emotional expressiveness was not significant, t = 1.44, p = .15. There was no

significant difference between mothers’ (M = 1.85 SD = .76) and fathers’ (M = 1.67, SD = .43)

ratios of positive to negative-nondominant emotional expressiveness, t = .86, p = .39. The

difference between mothers’ (M = .81, SD = .27) and fathers’ (M = .87 SD = .28) ratios of

negative-dominant to negative-nondominant emotional expressiveness was also not significant, t

= -1.89, p = .06.

Multilevel models. To examine whether parents’ emotional expressiveness and

25

children’s baseline RSA were associated with children’s prosocial behavior, multilevel models

were conducted using IBM SPSS Statistics 22.0. Multilevel models were used to account for the

nested structure of the data, specifically the interdependence between the older and younger

siblings’ prosocial behavior. Models were estimated with restricted maximum likelihood, as it

yields less biased estimates and standard errors when using small sample sizes (Snijders &

Bosker, 2012). Data were handled as repeated within the dyad, and heterogeneous compound

symmetry was used to permit errors to vary between the older and younger siblings (Kenny,

Kashy, & Cook, 2006). All continuous variables were grand mean centered. Sibling, the

distinguishing variable, was effect coded (OS = 1; YS = -1).

A series of models were conducted to explore the predictors of children’s helping and

sharing behavior. For each outcome variable (i.e., helping and sharing), due to the small size and

the need to limit the number of predictors, separate models were conducted for each dimension

of parents’ emotional expressiveness (i.e., positive, negative-dominant, and negative-

nondominant expressiveness).

To investigate whether the association between parental emotional expressiveness and

baseline RSA differed for older and younger siblings, interaction terms were created by

multiplying parents’ emotional expressiveness and baseline RSA variables by sibling (Aiken &

West, 1991). The power to detect interactions in non-experimental studies is low (McClelland

& Judd, 1993), and therefore it is recommended that interactions with p values of .10 and lower

should be probed (Kenny, 2014). Nonsignificant (greater than p = .10) interactions were

trimmed using a backward elimination method (Snijders & Bosker, 2012). Specifically, a full

model including all predictors was fit then nonsignificant interactions were subsequently

removed individually starting with the three-way interactions. Significant interactions were

26

plotted and simple slopes were calculated at +/- 1 SD from the mean (Aiken & West, 1991).

First, unconditional models were estimated to assess the interdependence between older

and younger siblings’ helping and sharing behaviors. Second, models were fit to determine

whether older and younger siblings’ sex, older and younger siblings’ age, children’s birth order,

age space between children, and sibling dyad gender composition needed to be included as

covariates in the subsequent analyses. Third, full models were estimated that included: (a) the

direct effects of mothers’ and fathers’ emotional expressiveness and children’s baseline RSA to

determine whether emotional expressiveness (Aim 2) and baseline RSA (Aim 3) were associated

with children’s prosocial behavior, (b) the emotional expressiveness x sibling interactions to

determine whether the associations between mothers’ and fathers’ emotional expressiveness and

children’s prosocial behavior differed for older and younger siblings (Aim 2a), (c) the baseline

RSA x sibling interactions to determine whether the association between baseline RSA and

children’s prosocial behavior differed for older and younger siblings (Aim 3a), (d) the emotional

expressiveness x baseline RSA interactions (e.g., baseline RSA x fathers’ expressiveness) to

determine whether baseline RSA moderated the association between parents’ emotional

expressiveness and children’s prosocial behavior (Aim 4), and (e) the emotional expressiveness x

baseline RSA x sibling interactions (e.g., mothers’ expressiveness x baseline RSA x sibling) to

examine whether the moderating effect of baseline RSA differed for older and younger siblings

(Aim 4a). Fourth, full models were estimated to include ratios of emotional expressiveness in

Aims 2, 3, and 4 to examine the relative proportions of each parent’s use of the different types of

emotional expressiveness.

Interdependence between older and younger siblings’ helping and sharing. The

interdependence between older and younger siblings’ helping behavior, as well as their sharing

27

behavior, was modeled as a covariance as opposed to a variance to allow for the potential

interdependence to be negative (Kenny et al., 2006). The results demonstrated that the

interdependence between older and younger siblings’ helping behavior was not significant, but

the interdependence between older and younger siblings’ sharing behavior was significant. For

helping, the intraclass correlation was .01 (SE = .13, p = .92; intercept estimate = .50, SE = .06, t

= 10.98, p < .001). For sharing, the intraclass correlation was .25 (SE = .13, p = .05; intercept

estimate = 2.13, SE = 1.98, t = 10.78, p < .001).

Covariates. Older and younger siblings’ sex, older and younger siblings’ age, children’s

birth order, age space between children, and sibling dyad gender composition were not

associated with children’s helping behavior or their sharing behavior. Therefore, no covariates

were included in the subsequent analyses.

Parental emotional expressiveness and children’s baseline RSA in association with

helping behavior. The final model of parents’ emotional expressiveness and children’s baseline

RSA predicting children’s helping behavior is presented in Table 3. Sibling was significantly

associated with children’s helping, demonstrating that older siblings showed more helping

behavior than younger siblings.

In the model that included mothers’ and fathers’ positive emotional expressiveness and

children’s baseline RSA predicting children’s helping behavior, there were no associations that

were significant. In the model that included mothers’ and fathers’ negative-dominant emotional

expressiveness and baseline RSA predicting children’s helping behavior, no significant

associations emerged. Lastly, for the model that included parents’ negative-nondominant

emotional expressiveness and children’s baseline RSA predicting children’s helping behavior,

there were no significant associations that emerged.

28

Parental emotional expressiveness and children’s baseline RSA in association with

sharing behavior. The final model of parents’ emotional expressiveness and children’s baseline

RSA predicting children’s sharing behavior is presented in Table 4.

In the model that included mothers’ and fathers’ positive emotional expressiveness and

children’s baseline RSA predicting children’s sharing behavior, there was a significant positive

association between mothers’ positive expressiveness and children’s sharing. This suggests that

children shared more when mothers reported expressing more positive emotions. The relation

between fathers’ emotional expressiveness and children’s sharing behavior was not significant,

nor was the relation between baseline RSA and children’s sharing significant. No significant

interactions emerged from this model.

In the model that included mothers’ and fathers’ negative-dominant emotional

expressiveness and children’s baseline RSA predicting children’s sharing behavior, the main

effects of mothers’ as well as fathers’ emotional expressiveness on children’s sharing were not

significant. Sibling moderated the association between maternal negative-dominant

expressiveness and children’s sharing behavior. The simple slope for the older sibling indicated

that older siblings shared less when mothers reported higher levels of negative-dominant

expressiveness (b = -.66, t = -2.46, p = .014; Figure 1). Younger siblings’ simple slope was not

significant (b = -.02, t = -.06, p = .95), demonstrating that there was no association between

mothers’ negative-dominant emotional expressiveness and younger siblings’ sharing. No other

interactions in the model were significant.

In the model that included mothers’ and fathers’ negative-nondominant emotional

expressiveness and children’s baseline RSA predicting children’s sharing behavior, the main

effects of mothers’ as well as fathers’ emotional expressiveness on children’s sharing were not

29

significant. Baseline RSA moderated the association between mothers’ negative-nondominant

expressiveness and children’s sharing. The simple slope for children with low baseline RSA

indicated that they shared more when mothers had higher levels of negative-nondominant

emotional expressiveness (b = .39, t = 2.12, p = .036; Figure 2). The simple slope for children

with high baseline RSA was not significant (b = -.19, t = -1.12, p = .27), demonstrating that there

was no association between mothers’ negative-nondominant emotional expressiveness and

children’s sharing for children with high baseline RSA. The association between children’s

baseline RSA and children’s sharing behavior was not significant.

Ratios of parental emotional expressiveness and children’s baseline RSA in

association with helping behavior. The final model of emotional expressiveness ratios and

children’s baseline RSA predicting children’s helping behavior is presented in Table 5.

In the model that included mothers’ and fathers’ ratios of positive to negative-dominant

emotional expressiveness and children’s baseline RSA predicting children’s helping behavior,

there were no associations that were significant. In the model that included mothers’ and fathers’

ratios of positive to negative-nondominant emotional expressiveness and baseline RSA

predicting children’s helping behavior, no significant associations emerged. Lastly, for the

model that included ratios of mothers’ and fathers’ negative-dominant to negative-nondominant

emotional expressiveness and children’s baseline RSA predicting children’s helping behavior,

there were no significant associations that emerged.

Ratios of parental emotional expressiveness and children’s baseline RSA in

association with sharing behavior. The final model of emotional expressiveness ratios and

children’s baseline RSA predicting children’s sharing behavior is presented in Table 6.

In the model that included mothers’ and fathers’ ratios of positive to negative-dominant

30

emotional expressiveness and children’s baseline RSA predicting children’s sharing behavior,

the results indicated that mothers’ emotional expressiveness was positively related to children’s

sharing behavior. This finding suggests that when mothers reported expressing more positive

emotion relative to their negative-dominant emotion, children shared more. The association

between fathers’ emotional expressiveness and children’s sharing was not significant. The

interaction between the ratio of mothers’ positive emotional expressiveness to her negative-

dominant emotional expressiveness and sibling predicting children’s sharing behavior was

marginally significant. The simple slope for the older siblings indicated that they shared more

when the ratio of mothers’ positive to negative-dominant emotional expressiveness was high, or

when mothers’ positive emotional expressiveness was relatively greater than her negative-

dominant expressiveness (b = .91, t = 2.58, p = .01; Figure 3). The simple slope for the younger

siblings was not significant (b = .21, t = .65, p = .52). No significant interactions with fathers’

emotional expressiveness emerged.

In the model that included mothers’ and fathers’ ratios of positive to negative-

nondominant emotional expressiveness and baseline RSA predicting children’s sharing behavior,

no significant associations emerged.

Lastly, for the model that included ratios of mothers’ and fathers’ negative-dominant to

negative-nondominant emotional expressiveness and children’s baseline RSA predicting

children’s sharing behavior, mothers’ emotional expressiveness was negatively related to

children’s sharing. This finding suggests that when mothers had greater negative-dominant

emotional expressiveness relative to their negative-nondominant emotional expressiveness,

children shared less. This association for fathers was not significant. No significant interactions

emerged.

31

Discussion

The emergence of prosocial behavior in early childhood is an important contributor to

children’s social competence when interacting with their family members and peers (Eisenberg

et al., 2006; Garner, Robertson, & Smith, 1997; Denham et al., 1990; Hastings et al., 2007).

Helping and sharing behaviors have been found to be distinct forms of prosocial behavior that

emerge early in life and follow different developmental trajectories (Dunfield et al., 2011;

Brownell et al., 2013; Dunn & Munn, 1986; Bryant & Crockenberg, 1980). The family’s

emotional climate contributes to young children’s social adjustment, exposing them to a variety

of emotions and teaching them how to respond to both positive and negative emotional stimuli

(Eisenberg et al., 1998; Ramsden & Hubbard, 2002). Parents’ reports of their own emotional

displays have been shown to influence children’s prosocial actions with their siblings more

specifically (Garner, Jones, & Miner, 1994). Further, it has been argued that children who have

higher levels of baseline RSA may be less sensitive to parents’ socialization than children with

lower baseline RSA (Hastings & De, 2008), which has important implications for the

development of prosocial behavior in the family context. The current study examined the

associations between parents’ emotional expressiveness and children’s helping and sharing

behaviors dependent upon children’s physiological regulation. Moreover, I investigated how

these relations differed for older and younger siblings, given that they are at different places in

their development of these prosocial behaviors.

The first aim was to investigate whether mothers and fathers differed in their levels of

emotional expressiveness. Consistent with what was hypothesized, I found that mothers

expressed more positive emotions than fathers. Past work has found that mothers report

displaying higher levels of positive emotion more frequently than fathers (Garner et al., 1997).

32

In contrast, mothers and fathers did not differ in their negative-dominant and negative-

nondominant expressiveness. These findings are somewhat surprising, given that other studies

have found that mothers report expressing more sadness (a negative-nondominant emotion), and

fathers often report demonstrating more anger (a negative-dominant emotion; Garner et al.,

1997). However, the literature on the types of emotions mothers and fathers express and to what

extent is mixed. For instance, past research has found that while mothers report displaying more

positive emotions, they also report more emotions overall, including negative emotions (Cassidy

et al., 1992). Future research would benefit from collecting both parents’ perceived levels of

emotional expressiveness as well as observational measures of emotional expression to more

comprehensively capture the emotional climate both mothers and fathers provide in the family

context. For instance, parents’ perceptions of how they express emotions around their children

may inform interventions to improve parental emotion socialization, especially if perceptions of

their expressions diverge from what they actually express.

Correlates of Children’s Sharing Behavior

The second aim of the study examined the relations between mothers’ and fathers’

emotional expressiveness and children’s sharing behavior, and whether these associations

differed for older and younger siblings. Consistent with what was expected, when mothers

reported expressing more positive emotions, children shared more. The existing literature has

found that mothers who show positive behavior in general have children who are prosocial with

their siblings (Howe & Ross, 1990; Garner et al., 1994). When mothers express more positive

emotions in the family context, children may experience less self-concern and be more adept at

responding to others’ emotions (Janssens & Gerris, 1992), particularly with other members of the

family, such as siblings. More specifically, children’s recognition of opportunities to share, as

33

well as their willingness to share with their siblings, may be heightened by a context in which

mothers show higher levels of positive expressiveness. Inconsistent with expectations, however,

was that fathers’ emotional expressiveness was not significantly related to children’s sharing

behavior. In past work, fathers’ positive emotional expressiveness, and not mothers’, has been

associated with kindergarteners’ helping and sharing behaviors (Boyum & Parke, 1995).

Additionally, children’s recognition of others’ emotions, which may be helpful in identifying

when situations warrant prosocial behavior, has been associated with fathers’ affective

expressions (Dunsmore et al., 2009). However, previous research on the roles of mothers’ and

fathers’ emotion socialization has found that mothers may have a greater influence on their

children’s socioemotional development than fathers (Morris et al., 2007). Mothers’ emotional

displays may be more salient to young children, particularly if mothers are reporting greater

levels of positive emotional expressiveness relative to fathers. Greater positive emotional

expression provided by mothers can afford children more resources for interacting positively

with others.

While the main effects of mothers’ negative-dominant and negative-nondominant

emotional expressiveness in association with children’s sharing were not significant, the second

aim of the study also investigated whether sibling influenced the relations between parental

emotional expressiveness and sharing. The results indicated that the relations between mothers’

negative-dominant emotional expressiveness and children’s sharing were different for older and

younger siblings, such that when mothers reported expressing more hostile negative emotions,

older siblings in the family shared less. In general, heightened distress in the family context,

such as exposure to harsh negative emotions, not unlike the negative-dominant emotions

reported in the current study, has been found to deter children’s attention away from situational

34

cues and the facial expressions of others (Eisenberg et al., 1990). Additionally, parents may

model their distress for their children through their higher levels of negative emotional

expressiveness, thus hampering their own abilities to appropriately regulate and demonstrate

effective expression strategies for their children. Higher levels of mothers’ negative-dominant

emotional expressiveness may be especially relevant for the older sibling in the family. Past

work has found that in the preschool years, older siblings initiate more prosocial behaviors

during sibling interactions and younger siblings respond to prosocial behaviors more positively

than older siblings (Abramovitch, Pepler, & Corter, 1980). These findings suggest that in early

childhood, younger siblings may be accustomed to watching the older sibling take the lead on

tasks and participating when the older sibling initiates a prosocial action, such as a sharing bid.

In general, older siblings are most likely, relative to the younger sibling, expected to be prosocial

in the family and model prosocial behavior for others in the family (Cicirelli, 1975; Eisenstadt,

1956). Therefore, they are perhaps more sensitive to parental emotion socialization than their

younger sibling might be. Given that they may be more susceptible to the parental socialization

of harsh emotions, they may not have the appropriate positive modeling from parents to engage

in prosocial behaviors with their younger siblings. Relatedly, the negative emotional climate

provided by mothers may cause them distress and harm their attentional capacities for tending to

the needs of others (Janssens & Gerris, 1992), which is required for engaging in sharing behavior

(Dunfield et al., 2011).

The association between mothers’ negative-nondominant expressiveness and children’s

sharing behavior did not differ for older and younger siblings. This suggests that there may be

an important distinction between the two types of negative expressiveness that mothers

demonstrate in the family context, given there were sibling differences in the association

35

between negative-dominant expressiveness and children’s sharing. In one study, mothers’

reported and observed negative-dominant emotional expressiveness were inversely related to

children’s effortful control, but the relations with negative-nondominant expressiveness were not

significant (Eisenberg et al., 2001). Negative emotional displays that are more submissive in

nature (i.e., expressions of worry or sadness) may neither help nor hinder sharing for a particular

sibling in the family, in that they may not provide the same level of distress in the emotional

climate as more hostile displays do.

The third aim of the current study was to investigate whether children’s baseline RSA

was associated with children’s sharing behavior, and if this relation differed for the older and

younger sibling in the family. I found that there was no link between baseline RSA and

children’s sharing and that there were no differences for siblings. This is similar to the research

of Hastings and De (2008), who found no direct relation between baseline RSA and children’s

social competence. Some work has found RSA withdrawal, rather than baseline RSA, to be

associated with children’s social functioning, such that children with greater withdrawal during

challenging tasks also had poorer social adjustment (Calkins, Graziano, & Keane, 2007). It has

also been established that when mothers use more negative control, children demonstrate poorer

physiological regulation during difficult social situations, in that vagal withdrawal during these

tasks was associated with more mobilized, defensive responding in the safe context (Hastings et

al., 2008). This supports the notion that parents may impact children’s physiological

mechanisms for effectively regulating their physiological state. Thus, changes in RSA may add

to our understanding of how children respond in the moment to social challenges (Porges, 1995),

such as sacrificing their own resource to satisfy the material need of another (i.e., sharing).

My fourth aim was to explore whether the link between parents’ emotional

36

expressiveness and children’s prosocial behavior differed as a function of children’s level of

baseline RSA, and whether these relations differed by sibling. The results demonstrated that

baseline RSA moderated the association between mothers’ negative-nondominant emotional

expressiveness and children’s sharing behavior, such that children with lower baseline RSA

shared more when mothers had higher levels of expressed submissive, negative emotions. In

contrast, parental emotional expressiveness was not associated with sharing for children with

higher baseline RSA. Expressions characterized by worry and low-level sadness can teach

children appropriate ways of expressing and recognizing negative affect without fostering

personal distress likely caused by events that are more hostile in nature (Cummings, 1987).

Further, these socialization experiences may be particularly important for children who have low

baseline RSA, as they are expected to have both a greater need for effectual parental emotion

socialization and a greater vulnerability for poor social engagement given an ineffective

socialization environment (Hastings & De, 2008). Previous work has delineated that children

with higher baseline RSA don’t have as substantial a need to rely on their parents’ cues for

socially engaging with their environment (Hastings & De, 2008). Baseline RSA may therefore

act as a protective or vulnerability factor that predisposes children toward certain social

functioning given how the emotional climate of the family operates.

Still, the broader literature on the role of parents’ negative-nondominant expressiveness

in children’s social and emotional development is largely mixed (Eisenberg et al., 1998).

Maternal submissive negative emotions, such as sadness, pain, and fear, have been associated

with toddlers’ greater observed concern for others (Crockenberg, 1985). On the other hand, high

levels of sadness, a submissive, negative expression in the family context, have been linked to

less caregiving behavior with siblings, such as physical and verbal comforting (Garner et al.,

37

1994). Relatedly, research has found evidence in support and in opposition of how children of

depressed parents engage in prosocial behavior (Hay& Pawlby, 2003). Children may internalize

their parents’ distress, limiting their capacities to engage with others prosocially. They also may

learn to be more empathetic toward others through a preoccupation with acting prosocial toward

the parent. This may be particularly relevant for promoting prosocial behavior in sibling

relationships, as the need to be prosocial may already be salient in the family context and

siblings may be more inclined to put aside their own material needs to share with one another.

Future work should examine prosocial behavior among siblings in families with a depressed

parent to better characterize the role that high submissive negative emotion plays in affecting

multiple family subsystems. In the current study, parents did not report high levels of negative-

nondominant expressiveness, which could explain the positive association, as moderated by

baseline RSA, between mothers’ negative-nondominant expressiveness and children’s sharing.

This finding highlights the need to examine how the parental expression of submissive negative

emotions may be particularly important for children with low RSA in terms of their prosocial

behavior, emphasizing the notion that compositing all negative emotional displays from parents

runs of the risk of overlooking important nuances of parents’ emotion socialization.

The extant literature has often made the assumption that negative and positive emotional

expressiveness fall on opposite sides of a continuum, but it important to acknowledge that an

individual’s level of one type of expression is not always correlated with other ways that they

express emotion (Diener et al., 1985). Recent work has delineated the need to investigate the

complexity of parental emotional expression, particularly the balance of emotions a parent

displays within the family context, and how it relates to children’s adjustment (e.g., Edwards,

2014). Thus, the current study was interested in examining ratios of parents’ own

38

expressiveness to better understand how relative levels of expression in the emotional climate

related to children’s prosocial behavior, and whether physiological regulation and sibling

contributed to these associations. The results supported the hypotheses of the second aim of the

study, indicating that when the ratio of mothers’ positive emotional expressiveness to their

negative-dominant emotional expressiveness was larger (i.e., mothers who had higher positive

expressiveness relative to their negative-dominant expressiveness), children engaged in more

sharing behavior. This is consistent with previous work on relations between parents’ emotional

balance and child outcomes, such that mothers with high levels of positive displays and low

levels of hostile negative displays in the family context have been found to have 4-year-old

children who express less negative affect and have greater emotion regulation (Nelson et al.,

2012). Children who come from homes where mothers demonstrate higher levels of positive

emotional expressiveness may feel more comfortable expressing positive emotions themselves

and engage in proper regulation strategies that allow them to adaptively interact in social

settings, such as ones that promote prosocial behavior. In conjunction, the low levels of negative

expressiveness mothers show may decrease the amount of distress in the home that could have

otherwise harmed children’s abilities to perform prosocial behaviors.

Also in support of what was predicted for the second aim of the study, results showed

that when the ratio of mothers’ negative-dominant to her negative-nondominant expressiveness

was high (i.e., mothers who had higher hostile negative expressiveness relative to their

submissive negative expressive), children displayed less sharing behavior. There is a dearth of

empirical literature on the relative proportions of these two types of negative expressiveness in

the family context. However, research has delineated that differentiating these forms of

expressiveness is important, given that they may have unique associations with children’s social

39

functioning. Children from homes high in hostile negative expressiveness have shown lower

levels of prosocial behavior (Boyum & Parke, 1995; Denham & Grout, 1992). Low levels of

submissive negative emotions such as sadness, on the other hand, may be helpful for the

development of children’s empathy (Crockenberg, 1985). It is suggested that children should be

exposed to some negative emotion in early childhood to learn how to express, understand, and

regulate their emotions in ways that are most adaptive for engaging in positive social situations

(Eisenberg et al., 1998), such as putting aside one’s own wants to share with another. Little is

known, however, on how much negative emotion, and perhaps more importantly, how much of

each type of negative emotion, is critical for socioemotional development. When taken together,

the levels of negative-dominant and negative-nondominant emotional expressiveness can inform

research on the ways in which certain negative emotions in the home can either be advantageous

or deleterious for children’s prosocial behavior development.

The associations between ratios of fathers’ emotional expressiveness and children’s

sharing were not significant. Again, the absence of relations among fathers’ emotional displays

and children’s sharing behavior was surprising, as there has been evidence to suggest that

fathers’ emotional expressiveness, over and above mothers’ emotional expressiveness, is related

to how their young children engage in challenging peer situations (Garner et al., 1997).

However, there has been some work suggesting that only mothers’ reported balance of emotional

expressiveness (i.e., their positive emotional expressiveness minus their negative emotional

expressiveness) is negatively related to children’s emotion knowledge, while only fathers’

balance of observed reactions to children’s greater emotional expressions is linked to children’s

emotion knowledge (Denham, Bassett, & Wyatt, 2010). Perhaps fathers’ reactions to children’s

emotions may be more salient to children than the degree to which fathers say they express

40

balanced levels of emotions in the family more generally.

Finally, the interaction of the ratio of mothers’ positive to negative-dominant emotional

expressiveness and sibling predicting children’s sharing behavior was marginally significant. In

other words, when mothers showed more positive emotional expressiveness relative to their

negative-dominant expressiveness, older siblings shared more. This is similar to the finding that

older siblings shared more when mothers had higher levels of negative-dominant expressiveness.

An emotional climate that is provided by the mother and characterized by high positivity

compared to negativity may be particularly important for the older sibling in the family. More

specifically, it may be more adaptive for the older sibling to pick up on positive emotional

displays that are not overridden by a hostile family environment as to promote prosocial behavior

toward their younger sibling.

Correlates of Children’s Helping Behavior

None of the associations with helping behavior were significant, with the exception of the

sibling predictor, such that older siblings were found to help more frequently than younger

siblings. Although the literature suggests that helping behavior typically does not increase across

18 to 76 months (Bar-Tal et al., 1982), older siblings, given the possibility of being expected to

help more, may engage in more helping behavior.

How little helping behavior occurred in the current study was surprising, given that

helping behavior typically comes online earlier in development than sharing. This is largely

because sharing requires the child to recognize that there is an equality between them and the

other individual, and they must be willing to sacrifice a resource in the process (Dunfield et al.,

2011). However, in the present study, there was limited variability for child helping. Helping

behavior was dichotomized because it occurred very infrequently with many instances of no

41

helping for the younger sibling. This limited the ability to detect associations between children’s

helping and parental emotional expressiveness, as well as with children’s physiological

regulation.

Limitations and Conclusions

The current study was one of the first to investigate, from a family systems perspective,

the roles of the family’s emotional climate and children’s baseline RSA in explicating

differences in the development of prosocial behavior in early childhood. Although interesting

results emerged, limitations need to be discussed. First, the sample was small for detecting

interaction effects. The sample was predominantly Caucasian thus it cannot generalize to

different populations. Because the study occurred at one point in time, it cannot be assumed that

parents influenced children’s development of prosocial behavior. It is important to note that the

conclusions drawn for explaining sibling differences are speculative, given that the variability of

younger siblings’ prosocial behavior was low. The lack of variability may be partially attributed

to lower levels of prosocial behavior that occur at this time in development (Eisenberg, 2005).

The current study was unique in that it examined helping and sharing behavior as

exclusive constructs, given the literature demonstrating their differentiated developmental

pathways (Dunfield et al., 2011). However, there were no significant associations between the

study’s predictor variables (with the exception of sibling) and children’s helping behavior.

Future work should observe prosocial behavior over a variety of sibling interactions to begin to

understand in what sibling contexts helping and sharing abilities are likely to arise. The present

study adds to the investigation of within-family processes that underpin children’s prosocial

development. Further, it examined the role of children’s dispositional physiological regulation in

moderating the association between mothers’ and fathers’ emotional expressiveness and

42

children’s prosocial behavior, and how these relations differed for the older and younger siblings

in the family. Despite the notion that a majority of children in the United States live in families

with more than one parent and grow up with at least one sibling, psychological research

overwhelmingly represents family processes within the confines of mother-child relationships.

This neglects the other pertinent relationships that influence a child’s environment and their

experiences within it. These results underscore the importance of a family systems perspective

in elucidating how parental emotional expressiveness and physiological regulation relate to

children’s emerging prosocial behavior.

43

References

Abramovitch, R., Pepler, D., & Corter, C. (1982). Patterns of sibling interaction among

preschool-age children. In M. E. Lamb & B. Sutton-Smith (Eds.), Sibling relationships:

Their nature and significance across the lifespan (pp. 61-86). New York, NY: Lawrence

Erlbaum Associates, Inc.

Aiken, L. S., & West, S. G. (1991). Multiple regression: Testing and interpreting interactions.

Thousand Oaks, CA: Sage Publications.

Asparouhov, T., & Muthén, B. O. (2010). Multiple imputation with Mplus. Technical Appendix.

Retrieved July 13, 2013, from: http://www.statmodel.com/download/Imputations7.pdf

Bar-Haim, Y., Marshall, P. J., & Fox, N. A. (2000). Developmental changes in heart period and

high-frequency heart period variability from 4 months to 4 years of age. Developmental

Psychobiology, 37(1), 44-56.

Bar-Tal, D., Raviv, A., & Goldberg, M. (1982). Helping behavior among preschool children: An

observational study. Child Development, 396-402.

Bar-Tal, D., Raviv, A., & Leiser, T. (1980). The development of altruistic behavior: Empirical

evidence. Developmental Psychology, 16(5), 516-524. doi: 10.1037/0012-1649.16.5.516

Beier, J. S., Over, H., & Carpenter, M. (2014). Young children help others to achieve their social

goals. Developmental Psychology, 50(3), 934-940.

Berntson, G. G., Quigley, K. S., Jang, J. F., & Boysen, S. T. (1990). An approach to artifact

identification: Application to heart period data. Psychophysiology, 27(5), 586-598.

Bornstein, M. H., & Suess, P. E. (2000). Child and mother cardiac vagal tone: continuity,

stability, and concordance across the first 5 years. Developmental Psychology, 36(1), 54-

65. doi: 10.1037/0012-1649.36.1.54

44

Boyum, L. A., & Parke, R. D. (1995). The role of family emotional expressiveness in the

development of children's social competence. Journal of Marriage and the Family, 57(3),

593-608.

Brody, L. R. (1985). Gender differences in emotional development: A review of theories and

research. Journal of Personality, 53(2), 102-149.

Brody, G. H., Stoneman, Z., & Burke, M. (1987). Child temperaments, maternal differential

behavior, and sibling relationships. Developmental Psychology, 23(3), 354-362.

Brownell, C. A., Svetlova, M., Anderson, R., Nichols, S. R., & Drummond, J. (2013).

Socialization of early prosocial behavior: parents’ talk about emotions is associated with

sharing and helping in toddlers. Infancy, 18(1), 91-119. doi: 10.1111/j.1532-

7078.2012.00125.x

Bryant, B. K., & Crockenberg, S. B. (1980). Correlates and dimensions of prosocial behavior: A

study of female siblings with their mothers. Child Development, 51(2), 529-544.

Calkins, S. D., & Fox, N. A. (2002). Self-regulatory processes in early personality development:

A multilevel approach to the study of childhood social withdrawal and

aggression. Development and Psychopathology, 14(3), 477-498. doi:

10.1017/S095457940200305X

Calkins, S. D., Graziano, P. A., & Keane, S. P. (2007). Cardiac vagal regulation differentiates

among children at risk for behavior problems. Biological Psychology, 74(2), 144–153.

doi: 10.1016/j.biopsycho.2006.09.005

Cassidy, J., Parke, R. D., Butkovsky, L., & Braungart, J. M. (1992). Family‐peer connections:

the roles of emotional expressiveness within the family and children's understanding of

emotions. Child Development, 63(3), 603-618. doi: 10.1111/j.1467-8624.1992.tb01649.x

45

Cicirelli, V. G. (1975). Effects of mother and older sibling on the problem-solving behavior of

the younger child. Developmental Psychology, 11(6), 749–756. doi: 10.1037/0012-

1649.11.6.749

Cox, M. J., & Paley, B. (1997). Families as systems. Annual Review of Psychology, 48(1), 243-

267. doi: 10.1146/annurev.psych.48.1.243

Crockenberg, S. (1985). Toddlers’ reactions to maternal anger. Merrill-Palmer Quarterly, 31,

361-373.

Cummings, E. M. (1987). Coping with Background Anger in Early Childhood. Child

Development, 58(4), 976–984. doi: 10.2307/1130538

Deater-Deckard, K. (1996). Within family variability in parental negativity and control. Journal

of Applied Developmental Psychology, 17(3), 407-422.

Denham, S. A., Bassett, H. H., & Wyatt, T. M. (2010). Gender differences in the socialization of

preschoolers' emotional competence. New Directions for Child and Adolescent

Development, 2010(128), 29-49. doi: 10.1002/cd.267

Denham, S. A., & Grout, L. (1992). Mothers' emotional expressiveness and coping: Relations

with preschoolers' social-emotional competence. Genetic, Social, and General

Psychology Monographs, 118(1), 73-101.

Denham, S. A., McKinley, M., Couchoud, E. A., & Holt, R. (1990). Emotional and behavioral

predictors of preschool peer ratings. Child Development, 61(4), 1145-1152. doi:

10.1111/j.1467-8624.1990.tb02848.x

Denham, S. A., Mitchell-Copeland, J., Strandberg, K., Auerbach, S., & Blair, K. (1997). Parental

Contributions to Preschoolers’ Emotional Competence: Direct and Indirect Effects.

Motivation and Emotion, 21(1), 65–86. doi: 10.1023/A:1024426431247

46

Diener, E., Larsen, R. J., Levine, S., & Emmons, R. A. (1985). Intensity and frequency:

Dimensions underlying positive and negative affect. Journal of Personality and Social

Psychology, 48(5), 1253–1265. doi: 10.1037/0022-3514.48.5.1253

Dunfield, K., Kuhlmeier, V. A., O’Connell, L., & Kelley, E. (2011). Examining the diversity of

prosocial behavior: Helping, sharing, and comforting in infancy. Infancy, 16(3), 227-247.

doi: 10.1111/j.1532-7078.2010.00041.x

Dunn, J., & Munn, P. (1986). Siblings and the development of prosocial behaviour. International

Journal of Behavioral Development, 9(3), 265-284. doi: 10.1177/016502548600900301

Dunsmore, J. C., Her, P., Halberstadt, A. G., & Perez-Rivera, M. B. (2009). Parents’ beliefs

about emotions and children’s recognition of parents’ emotions. Journal of Nonverbal

Behavior, 33(2), 121-140.

Eisenberg, N. (2000). Emotion, regulation, and moral development. Annual Review of

Psychology, 51(1), 665-697. doi: 10.1146/annurev.psych.51.1.665

Eisenberg, N. (2005). The development of empathy-related responding. In G. Carlo & C. P.

Edwards (Eds.), Nebraska symposium of motivation: Vol. 51. Moral motivation through

the life span (pp. 73-117). Lincoln: University of Nebraska Press.

Eisenberg, N., Cumberland, A., & Spinrad, T. L. (1998). Parental socialization of

emotion. Psychological Inquiry, 9(4), 241-273. doi: 10.1207/s15327965pli0904_1

Eisenberg, N., & Fabes, R. A. (1998). Prosocial development. In W. Damon (Series Ed.) & N.

Eisenberg (Vol. Ed.), Handbook of child psychology: Vol. 3. Social, Emotional, and

Personality Development (5th ed., pp. 701–778). New York: Wiley.

47

Eisenberg, N., Fabes, R. A., Karbon, M., Murphy, B. C., Wosinski, M., Polazzi, L., ... & Juhnke,

C. (1996). The relations of children's dispositional prosocial behavior to emotionality,

regulation, and social functioning. Child Development, 67(3), 974-992.

Eisenberg, N., Fabes, R. A., & Spinrad, T. L. (2006). Prosocial development. In N. Eisenberg

(Vol. Ed) and W. Damon & R. M. Lerner (Series Eds.), Handbook of child psychology:

vol. 3, social, emotional, and personality development (6th ed., pp. 646-718). New York,

New York: Wiley.

Eisenberg, N., Gershoff, E. T., Fabes, R. A., Shepard, S. A., Cumberland, A. J., Losoya, S. H., ...

& Murphy, B. C. (2001). Mother's emotional expressivity and children's behavior

problems and social competence: Mediation through children's regulation. Developmental

Psychology, 37(4), 475-490.

Eisenberg-Berg, N., & Hand, M. (1979). The relationship of preschoolers' reasoning about

prosocial moral conflicts to prosocial behavior. Child Development, 50(2), 356-363.

Eisenberg, N., & Miller, P. A. (1987). The relation of empathy to prosocial and related

behaviors. Psychological Bulletin, 101(1), 91-119. doi: 10.1037/0033-2909.101.1.91

Eisenstadt, S. N. (1956). From Generation to Generation: Age Groups and Social Structure.

Transaction Publishers.

El-Sheikh, M., Harger, J., & Whitson, S. M. (2001). Exposure to interparental conflict and

children's adjustment and physical health: The moderating role of vagal tone. Child

development, 72(6), 1617-1636.

Ensor, R., Spencer, D., & Hughes, C. (2011). ‘You Feel Sad?’ Emotion understanding mediates

effects of verbal ability and mother–child mutuality on prosocial behaviors: findings from

48

2 years to 4 years. Social Development, 20(1), 93-110. doi: 10.1111/j.1467-

9507.2009.00572.x

Eron, L. D., & Huesmann, L. R. (1984). The relation of prosocial behavior to the development of

aggression and psychopathology. Aggressive Behavior, 10(1), 201-211.

Feinberg, M., & Hetherington, E. M. (2001). Differential parenting as a within-family

variable. Journal of Family Psychology, 15(1), 22-37. doi: 10.1037/0893-3200.15.1.22

Garner, P. W., Jones, D. C., & Miner, J. L. (1994). Social competence among low‐income

preschoolers: Emotion socialization practices and social cognitive correlates. Child

Development, 65(2), 622-637.

Garner, P. W., & Power, T. G. (1996). Preschoolers' emotional control in the disappointment

paradigm and its relation to temperament, emotional knowledge, and family

expressiveness. Child Development, 67(4), 1406-1419. doi: 10.1111/j.1467-

8624.1996.tb01804.x

Garner, P. W., Robertson, S., & Smith, G. (1997). Preschool children's emotional expressions

with peers: The roles of gender and emotion socialization. Sex Roles, 36(11-12), 675-691.

Grusec, J. E., & Goodnow, J. J. (1994). Impact of parental discipline methods on the child's

internalization of values: A reconceptualization of current points of view. Developmental

Psychology, 30(1), 4-19. doi: 10.1037/0012-1649.30.1.4

Halberstadt, A. G. (1986). Family socialization of emotional expression and nonverbal

communication styles and skills. Journal of Personality and Social Psychology, 51(4),

827-836. doi: 10.1037/0022-3514.51.4.827

49

Halberstadt, A. G., Cassidy, J., Stifter, C. A., Parke, R. D., & Fox, N. A. (1995). Self-

expressiveness within the family context: Psychometric support for a new

measure. Psychological Assessment, 7(1), 93-103.

Hastings, P. D., & De, I. (2008). Parasympathetic regulation and parental socialization of

emotion: Biopsychosocial processes of adjustment in preschoolers. Social

Development, 17(2), 211-238. doi: 10.1111/j.1467-9507.2007.00422.x

Hastings, P. D., Nuselovici, J. N., Utendale, W. T., Coutya, J., McShane, K. E., & Sullivan, C.

(2008). Applying the polyvagal theory to children's emotion regulation: Social context,

socialization, and adjustment. Biological Psychology, 79(3), 299-306.

Hastings, P. D., Utendale, W. T., & Sullivan, C. (2007). The socialization of prosocial behavior.

In J. E. Grusec, & P. D. Hastings (Eds.) Handbook of socialization: Theory and research

(pp. 638-664). New York and London: The Guildford Press.

Hay, D. F., Caplan, M., Castle, J., & Stimson, C. A. (1991). Does sharing become increasingly"

rational" in the second year of life? Developmental Psychology, 27(6), 987-993. doi:

10.1037/0012-1649.27.6.987

Hay, D. F., & Pawlby, S. (2003). Prosocial Development in Relation to Children’s and Mothers’

Psychological Problems. Child Development, 74(5), 1314–1327.

Hinnant, J. B., & El-Sheikh, M. (2009). Children’s externalizing and internalizing symptoms

over time: The role of individual differences in patterns of RSA responding. Journal of

Abnormal Child Psychology, 37(8), 1049-1061.

Hoffman, M. L. (1977). Empathy, its development and prosocial implications. In C. B. Keasey

(Ed.), Nebraska Symposium on Motivation (Vol. 25). Lincoln: University of Nebraska

Press.

50

Howe, N., & Ross, H. S. (1990). Socialization, perspective-taking, and the sibling relationship.

Developmental Psychology, 26(1), 160–165. http://doi.org/10.1037/0012-1649.26.1.160

Iannotti, R. J. (1985). Naturalistic and structured assessments of prosocial behavior in preschool

children: The influence of empathy and perspective taking. Developmental

Psychology, 21(1), 46-55.

Isley, S. L., O'Neil, R., Clatfelter, D., & Parke, R. D. (1999). Parent and child expressed affect

and children's social competence: Modeling direct and indirect pathways. Developmental

Psychology, 35(2), 547. doi: 10.1037/0012-1649.35.2.547

Janssens, J. M. A. M., & Gerris, J. R. M. (1992). Childrearing, empathy, and prosocial

development. In J. M. A. M. Janssens, & J. R. M. Gerris (Eds.), Childrearing: Influence

on prosocial and moral development (pp. 57-77). Amsterdam: Swets & Zeitlinger.

Kenny, D. A. (2014). Moderation: Effect size and power [Webinar]. From

http://davidakenny.net/webinars/Moderation/Power/Power.html

Kenny, D. A., Kashy, D. A., & Cook, W. L. (2006). Dyadic data analysis. New York: Guildford

Press.

Knafo, A., & Plomin, R. (2006). Prosocial behavior from early to middle childhood: Genetic and

environmental influences on stability and change. Developmental Psychology, 42(5),

771-786. doi: 10.1037/0012-1649.42.5.771

Kok, B. E., Coffey, K. A., Cohn, M. A., Catalino, L. I., Vacharkulksemsuk, T., Algoe, S. B., ...

& Fredrickson, B. L. (2013). How positive emotions build physical health perceived

positive social connections account for the upward spiral between positive emotions and

vagal tone. Psychological Science, 24(7), 1123-1132. doi: 10.1177/0956797612470827

51

Kok, B. E., & Fredrickson, B. L. (2010). Upward spirals of the heart: Autonomic flexibility, as

indexed by vagal tone, reciprocally and prospectively predicts positive emotions and

social connectedness. Biological psychology, 85(3), 432-436. doi:

10.1016/j.biopsycho.2010.09.005

Lamb, M. E., & Lewis, C. (2010). The development and significance of father-child relationships

in two-parent families The role of the father in child development (5th ed., pp. 94-153).

Hoboken, NJ, US: John Wiley & Sons Inc.

Liszkowski, U., Carpenter, M., Striano, T., & Tomasello, M. (2006). 12-and 18-month-olds point

to provide information for others. Journal of Cognition and Development, 7(2), 173-187.

doi: 10.1207/s15327647jcd0702_2

MacDonald, K., & Parke, R. D. (1984). Bridging the gap: Parent-child play interaction and peer

interactive competence. Child Development, 55(4), 1265-1277.

McClelland, G. H., & Judd, C. M. (1993). Statistical difficulties of detecting interactions and

moderator effects. Psychological Bulletin, 114(2), 376-390. doi: 10.1037/0033-

2909.114.2.376

Muthén, L. K., & Muthén, B. O. (1998–2012). Mplus user's guide (7th ed.). Los Angeles, CA:

Muthén & Muthén.

Nelson, J. A., O’Brien, M., Calkins, S. D., Leerkes, E. M., Marcovitch, S., & Blankson, A. N.

(2012). Maternal Expressive Style and Children’s Emotional Development. Infant and

Child Development, 21(3), 267–286. http://doi.org/10.1002/icd.748

Paulus, M., & Moore, C. (2014). The development of recipient-dependent sharing behavior and

sharing expectations in preschool children. Developmental Psychology, 50(3), 914-921.

52

Porges, S. W. (1995). Cardiac vagal tone: A physiological index of stress. Neuroscience &

Biobehavioral Reviews, 19(2), 225–233. doi: 10.1016/0149-7634(94)00066-A

Porges, S. W. (2007). The polyvagal perspective. Biological Psychology, 74(2), 116-143. doi:

10.1016/j.biopsycho.2006.06.009

Porges, S. W., Doussard‐Roosevelt, J. A., Lourdes Portales, A., & Suess, P. E. (1994). Cardiac

vagal tone: Stability and relation to difficultness in infants and 3‐ year‐

Olds. Developmental Psychobiology, 27(5), 289-300. doi: 10.1002/dev.420270504

Porges, S. W., & Furman, S. A. (2011). The early development of the autonomic nervous system

provides a neural platform for social behaviour: A polyvagal perspective. Infant and

Child Development, 20(1), 106-118.

Radke-Yarrow, M., Zahn-Waxler, C., & Chapman, M. (1983). Children's prosocial disposition

and behavior. In E. M. Hetherington (Ed.), Handbook of child psychology: Socialization,

personality, and social development (Vol. 4, pp. 469-545). New York: Wiley.

Ramsden, S. R., & Hubbard, J. A. (2002). Family Expressiveness and Parental Emotion

Coaching: Their Role in Children’s Emotion Regulation and Aggression. Journal of

Abnormal Child Psychology, 30(6), 657–667. doi: 10.1023/A:1020819915881

Rheingold, H. L., Hay, D. F., & West, M. J. (1976). Sharing in the second year of life. Child

Development, 47(4), 1148-1158.

Sebastián-Enesco, C., & Warneken, F. (2015). The shadow of the future: 5-Year-olds, but not 3-

year-olds, adjust their sharing in anticipation of reciprocation. Journal of Experimental

Child Psychology, 129, 40-54.

Snijders, T. A. B., & Bosker, R. J. (2012). Multilevel analysis: An introduction to basic and

advanced multilevel modeling (2nd ed.). Thousand Oaks, CA: Sage.

53

Stifter, C. A., & Fox, N. A. (1990). Infant reactivity: Physiological correlates of newborn and 5-

month temperament. Developmental Psychology, 26(4), 582-588. doi: 10.1037/0012-

1649.26.4.582

Thompson, C., Barresi, J., & Moore, C. (1997). The development of future-oriented prudence

and altruism in preschoolers. Cognitive Development, 12, 199–212.

Valiente, C., Eisenberg, N., Fabes, R. A., Shepard, S. A., Cumberland, A., & Losoya, S. H.

(2004). Prediction of children's empathy-related responding from their effortful control

and parents' expressivity. Developmental Psychology, 40(6), 911. doi: 10.1037/0012-

1649.40.6.911

Warneken, F., & Tomasello, M. (2006). Altruistic helping in human infants and young

chimpanzees. Science, 311(5765), 1301-1303. doi: 10.1126/science.1121448

Warneken, F., & Tomasello, M. (2007). Helping and cooperation at 14 months of

age. Infancy, 11(3), 271-294. doi: 10.1080/15250000701310389

Yarrow, M. R., Waxler, C. Z., Barrett, D., Darby, J., King, R., Pickett, M., & Smith, J. (1976).

Dimensions and correlates of prosocial behavior in young children. Child Development,

47(1), 118-125.

Zhou, Q., Eisenberg, N., Losoya, S. H., Fabes, R. A., Reiser, M., Guthrie, I. K., ... & Shepard, S.

A. (2002). The Relations of Parental Warmth and Positive Expressiveness to Children's

Empathy‐Related Responding and Social Functioning: A Longitudinal Study. Child

Development, 73(3), 893-915. doi: 10.1111/1467-8624.00446

54

Appendix A: Tables

Table 1

Descriptive Statistics.

Older Sibling Younger Sibling

M SD M SD

Helping .73 .46 .28 .44

Sharing 2.28 2.01 1.98 1.91

BLRSA 5.81 1.29 4.91 1.46

Mother Father

M SD M SD

Pos. EE 6.77 1.06 6.31 1.19

N-D EE 3.13 1.0 3.34 1.13

N-ND EE 4.09 1.36 3.99 1.14

Pos. to N-D EE Ratio 2.40 .90 2.16 1.05

Pos. to N-ND EE Ratio 1.85 .76 1.67 .43

N-D to N-ND EE Ratio .81 .27 .87 .28

Note. Descriptive statistics for helping and sharing were calculated using the recoded

weighted frequencies. BLRSA = baseline RSA, EE = emotional expressiveness, Pos. =

positive, N-D = negative-dominant, N-ND = negative-nondominant.

55

Table 2

Correlations among Study Variables.

Measure 1 2 3 4 5 6 7 8

1. OS Helping ---- .148 .071 .264* -.132 .017 .129 -.189

2. OS Sharing ---- ---- .025 .175 .255 .329* .311* -.315*

3. OS BLRSA ---- ---- ---- .040 .173 .277* .503** .142

4. YS Helping ---- ---- ---- ---- .160 .154 .137 -.136

5. YS Sharing ---- ----- ---- ---- ---- .260 .178 -.011

6. YS BLRSA ---- ---- ---- ---- ---- ---- .244 .057

7. Pos. EE .163 .121 -.118 .074 -.055 -.150 .313* .062

8. N-D EE -.131 -.084 -.239 .126 -.001 -.052 -.057 .132

9. N-ND EE .040 .002 -.158 .165 .011 -.007 .524** .518**

10. Ratio Pos. to N-D EE .152 .028 .196 -.075 -.065 -.054 .512** -.769**

11. Ratio Pos. to N-ND EE .050 .031 .069 -.170 -.041 -.094 .178 -.577**

12. Ratio N-D to N-ND EE -.169 -.121 -.072 -.067 -.020 -.066 -.618** .497**

Note. Correlations above the diagonal are for the mother and below the diagonal are for the father. Cross-parent

56

correlations are on the diagonal (bolded). OS = older sibling, YS = younger sibling. BLRSA = baseline RSA, EE =

emotional expressiveness, Pos. = positive, N-D = negative-dominant, N-ND = negative- nondominant. * p < .05. ** p <

.01.

57

Table 2 (continued)

Correlations among study variables.

Measure 9 10 11 12

1. OS Helping -.109 .136 .191 .005

2. OS Sharing -.086 .380** .106 -.270*

3. OS BLRSA .207 .093 .042 -.107

4. YS Helping .002 .191 .040 -.150

5. YS Sharing .203 .096 -.119 -.257*

6. YS BLRSA .271* .080 -.176 -.272

7. Pos. EE .354** .393** .115 -.334*

8. N-D EE .637** -.812** -.510** .259

9. N-ND EE .044 -.355* -.772** -.512**

10. Ratio Pos. to N-D EE -.142 .023 .520** -.407**

11. Ratio Pos. to N-ND EE -.693** .557** -.009 .516**

12. Ratio N-D to N-ND EE -.429** -.704** .046 .171

Note. Correlations above the diagonal are for the mother and below the diagonal

58

are for the father. Cross-parent correlations are on the diagonal (bolded). OS =

older sibling, YS = younger sibling. BLRSA = baseline RSA, EE = emotional

expressiveness, Pos. = positive, N-D = negative-dominant, N-ND = negative-

nondominant. * p < .05. ** p < .01.

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Table 3

Multilevel models examining mothers’ and fathers’ emotional expressiveness and children’s baseline RSA as correlates of children’s helping behavior.

Positive Negative-Dominant Negative-Nondominant

Variable Estimate SE t Estimate SE t Estimate SE t

Intercept .50** .05 11.05 .50** .05 11.14 .50** .05 11.05

Sibling .21** .04 5.40 .21** .04 5.40 .21** .04 5.34

BLRSA .04 .03 1.04 .04 .03 1.38 .05 .03 1.40

M EE .02 .05 .47 -.08 .05 -1.75 -.03 .04 -.88

F EE .04 .04 1.06 .02 .04 .41 .05 .04 1.16

Sibling x BLRSA ---- ---- ---- ---- ---- ---- ---- ---- ----

M EE x F EE ---- ---- ---- ---- ---- ---- ---- ---- ----

M EE x Sibling ---- ---- ---- ---- ---- ---- ---- ---- ----

M EE x BLRSA ---- ---- ---- ---- ---- ---- ---- ---- ----

M EE x Sibling x BLRSA ---- ---- ---- ---- ---- ---- ---- ---- ----

F EE x Sibling ---- ---- ---- ---- ---- ---- ---- ---- ----

F EE x BLRSA ---- ---- ---- ---- ---- ---- ---- ---- ----

F EE x Sibling x BLRSA ---- ---- ---- ---- ---- ---- ---- ---- ----

Note. Estimates are unstandardized regression coefficients. SE = Standard Error. M = mother, F = father. BLRSA = baseline RSA, EE = emotional expressiveness. † p < .10. *

p < .05. ** p < .01.

60

Table 4

Multilevel models examining mothers’ and fathers’ emotional expressiveness and children’s baseline RSA as correlates of children’s sharing behavior.

Positive Negative-Dominant Negative-Nondominant

Variable Estimate SE t Estimate SE t Estimate SE t

Intercept 2.13 ** .19 11.17 2.13** .19 11.12 2.22 ** .20 11.09

Sibling .14 .17 .78 .07 .17 .44 .10 .16 .58

BLRSA .03 .15 .19 .17 .14 1.21 .08 .14 .57

M EE .44* .21 2.12 -.37 .21 -1.76 .10 .16 .62

F EE -.07 .18 -.40 -.01 .17 -.04 .09 .17 .52

Sibling x BLRSA ---- ---- ---- ---- ---- ---- ---- ---- ----

M EE x F EE ---- ---- ---- ---- ---- ---- ---- ---- ----

M EE x Sibling ---- ---- ---- -.33* .16 -2.03 ---- ---- ----

M EE x BLRSA ---- ---- ---- ---- ---- ---- -.20* .08 -2.51

M EE x Sibling x BLRSA ---- ---- ---- ---- ---- ---- ---- ---- ----

F EE x Sibling ---- ---- ---- ---- ---- ---- ---- ---- ----

F EE x BLRSA ---- ---- ---- ---- ---- ---- ---- ---- ----

F EE x Sibling x BLRSA ---- ---- ---- ---- ---- ---- ---- ---- ----

Note. Estimates are unstandardized regression coefficients. SE = Standard Error. M = mother, F = father. BLRSA = baseline RSA, EE = emotional expressiveness. † p < .10. *

p < .05. ** p < .01.

61

Table 5

Multilevel models examining mothers’ and fathers’ ratios of emotional expressiveness and children’s baseline RSA as correlates of children’s helping behavior.

Positive Negative-Dominant Negative-Nondominant

Variable Estimate SE t Estimate SE t Estimate SE t

Intercept .50** .05 11.09 .50** .05 11.04 .50** .05 10.99

Sibling .21** .04 5.53 .21** .04 5.45 .21** .04 5.49

BLRSA .03 .03 1.07 .04 .03 1.25 .03 .03 1.06

M EE .08 .06 1.46 .08 .07 1.17 -.06 .19 -.99

F EE .01 .05 .29 -.06 .10 -.56 -.16 .17 -.33

Sibling x BLRSA ---- ---- ---- ---- ---- ---- ---- ---- ----

M EE x F EE ---- ---- ---- ---- ---- ---- ---- ---- ----

M EE x Sibling ---- ---- ---- ---- ---- ---- ---- ---- ----

M EE x BLRSA ---- ---- ---- ---- ---- ---- ---- ---- ----

M EE x Sibling x BLRSA ---- ---- ---- ---- ---- ---- ---- ---- ----

F EE x Sibling ---- ---- ---- ---- ---- ---- ---- ---- ----

F EE x BLRSA ---- ---- ---- ---- ---- ---- ---- ---- ----

F EE x Sibling x BLRSA ---- ---- ---- ---- ---- ---- ---- ---- ----

Note. Estimates are unstandardized regression coefficients. SE = Standard Error. M = mother, F = father. BLRSA = baseline RSA, EE = emotional expressiveness. † p < .10. *

p < .05. ** p < .01.

62

Table 6

Multilevel models examining mothers’ and fathers’ ratios of emotional expressiveness and children’s baseline RSA as correlates of children’s sharing behavior.

Positive Negative-Dominant Negative-Nondominant

Variable Estimate SE t Estimate SE t Estimate SE t

Intercept 2.13 ** .19 11.36 2.13** .20 10.91 2.13 ** .19 11.37

Sibling .10 .17 .59 .09 .17 .50 .11 .17 .63

BLRSA .11 .14 .82 .14 .14 1.00 .09 .14 .65

M EE .56* .27 2.04 -.02 .32 -.05 -1.90* .82 -2.31

F EE -.06 .20 -.27 -.02 .44 -.05 -.15 .68 -.22

Sibling x BLRSA ---- ---- ---- ---- ---- ---- ---- ---- ----

M EE x F EE ---- ---- ---- ---- ---- ---- ---- ---- ----

M EE x Sibling .35† .20 1.74 ---- ---- ---- ---- ---- ----

M EE x BLRSA ---- ---- ---- ---- ---- ---- ---- ---- ----

M EE x Sibling x BLRSA ---- ---- ---- ---- ---- ---- ---- ---- ----

F EE x Sibling ---- ---- ---- ---- ---- ---- ---- ---- ----

F EE x BLRSA ---- ---- ---- ---- ---- ---- ---- ---- ----

F EE x Sibling x BLRSA ---- ---- ---- ---- ---- ---- ---- ---- ----

Note. Estimates are unstandardized regression coefficients. SE = Standard Error. M = mother, F = father. BLRSA = baseline RSA, EE = emotional expressiveness. † p < .10. *

p < .05. ** p < .01.

63

Appendix B: Figures

Figure 1. The interaction between mothers’ negative-dominant emotional expressiveness and

sibling predicting children’s sharing.

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

5

Low High

Chil

dre

n's

Shar

ing

Mother N-D EE

YS

OS

64

Figure 2. The interaction between mothers’ negative-nondominant emotional expressiveness and

children’s baseline RSA predicting children’s sharing.

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

5

Low High

Chil

dre

n's

Shar

ing

Mother N-ND EE

Low

Blrsa

High

Blrsa

65

Figure 3. The interaction between the ratio of mothers’ positive to negative-dominant emotional

expressiveness and sibling predicting children’s sharing.

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

5

Low High

Chil

dre

n's

Shar

ing

Ratio of Mother Pos. to N-D EE

YS

OS