Examining Social Influence in Information-Sharing Contexts

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2003 34: 391Small Group ResearchDavid Dryden Henningsen and Mary Lynn Miller Henningsen

Examining Social Influence in Information-Sharing Contexts

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10.1177/1046496403251933 ARTICLESMALL GROUP RESEARCH / August 2003Henningsen, Henningsen / NORMATIVE AND INFORMATIONAL INFLUENCE

EXAMINING SOCIAL INFLUENCE

IN INFORMATION-SHARING

CONTEXTS

DAVID DRYDEN HENNINGSEN

MARY LYNN MILLER HENNINGSEN

Northern Illinois University

Research on hidden profiles has found that groups tend to make decisions reflecting the

information shared among groupmembers prior to discussion.However, shared information

is confounded with individual prediscussion preferences in hidden profile situations. In this

article, the authors manipulate information distribution to examine hidden, ambiguous (i.e.,

prediscussion preferences favor no alternative), and clear (i.e., prediscussion preferences

support the decision alternative favored by the total information) profiles. They examine the

influence of profile type on group decisions, use of shared and unshared information, and

perceptions of normative and informational influence. Results indicate that groups make

superior decisions and rely more on unshared information in clear and ambiguous profiles

than in hidden profiles. In addition, perceived social influence is most prevalent in ambigu-

ous profiles.

Keywords: normative influence; informational influence; information sharing; hidden pro-

file; group decision making

There is a growingbody of research focusing on the importance of

information exchange in decision-making groups (Brodbeck,

Kerschreiter,Mojzisch, Frey,&Schultz-Hardt, 2002; Cruz, Boster,

& Rodriguez, 1997; Cruz, Henningsen, & Smith, 1999; Dennis,

1996;Gigone&Hastie, 1993, 1997;Gruenfeld,Mannix,Williams,

&Neale, 1996; Hollingshead, 1996a, 1996b; Kameda, Ohtsubo, &

Takezawa, 1997; Larson, Christensen, Abbott, & Franz, 1996;

391

AUTHORS’ NOTE: Address correspondence concerning this article to David Dryden

Henningsen, Department of Communication, Northern Illinois University, Dekalb, IL

60115.

SMALL GROUP RESEARCH, Vol. 34 No. 4, August 2003 391-412

DOI: 10.1177/1046496403251933

© 2003 Sage Publications

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Larson, Christensen, Franz, & Abbott, 1998; Larson, Foster-

Fishman, & Granz, 1998; Larson, Foster-Fishman, & Keys, 1994;

Lavery, Franz, Winquist, & Larson, 1999; Mennecke, 1997;

Postmes, Spears, & Cihangir, 2001; Propp, 1997; Savadori, Van

Swol, & Sniezek, 2001; Schittekatte, 1996; Schittekatte & Van

Hiel, 1996; Shaw & Penrod, 1962; Stasser & Stewart, 1992;

Stasser, Stewart, & Wittenbaum, 1995; Stasser, Taylor, & Hanna,

1989; Stasser & Titus, 1985, 1987; Stasser, Vaughn, & Stewart,

2000; Stewart, 1998; Stewart, Billings, & Stasser, 1998; Stewart &

Stasser, 1995, 1998; Van Hiel & Schittekatte, 1998; Winquist &

Larson, 1998; Wittenbaum, 1998, 2000; Wittenbaum, Hubbell, &

Zuckerman, 1999; Wittenbaum & Stasser, 1998; Wittenbaum,

Stasser, & Merry, 1996). This research consistently has demon-

strated that shared information (i.e., information held by all group

members) tends to be pooled in discussion more than unshared

information (i.e., information held by only one group member).

Overall, past research has indicated that shared information tends

to have a greater influence on group decision making than does

unshared information.

An overreliance on shared information is problematic for groups

when shared information favors a suboptimal decision alternative

but the information as a whole favors the best decision alternative.

Under these circumstances, relying on shared information at the

expense of unshared information could lead to faulty decisionmak-

ing. The negative influence over reliance on shared information can

have on decision making is clearly demonstrated in research using

hidden profiles (Stasser, 1988). In a hidden profile, the information

held by each individual group member favors a suboptimal deci-

sion alternative. However, the total information held by all group

members favors a better decision. If group members pool all of the

unshared information, the best alternative should become apparent.

Unfortunately, groupswith hidden profiles select the suboptimal

decision alternative more frequently than they select the best deci-

sion alternative. In contrast, groups in which all information is ini-

tially shared select the best alternative more than hidden profile

groups (e.g., Cruz et al., 1997; Hollingshead, 1996b;Kelly&Karau,

1999; Stasser & Titus, 1985). Stasser and Titus (1985) showed that

392 SMALL GROUP RESEARCH / August 2003



group discussion decreased the percentage of groupmembersmak-

ing optimal decisions under hidden profile conditions. This indi-

cates that social influence occurs in decision-making groups deal-

ing with hidden profiles. In the present study, we will examine how

social influence works under different information profiles.

SOURCES OF INFLUENCE

Researchers have identified two types of social influence in

decision-making contexts (Deutsch & Gerard, 1955; Kaplan &

Miller, 1987). Normative influence occurs when individuals make

decisions to gain approval from other group members. Informa-

tional influence, on the other hand, occurs when individuals make

decisions to reach the best possible decision.

Based on these definitions, normative influence occurs in groups

when discussion content presents the positions favored by other

group members (Kaplan &Miller, 1987). If normative influence is

effective, change their positions to the position favored by the

majority in order to fit in with the group. In contrast, informational

influence should occur when facts, evidence, or other forms of

information pertinent to the decision are discussed by group mem-

bers and cause them to reevaluate their positions (Kaplan &Miller,

1987). Researchers have operationalized normative influence as

the statements in discussion that indicate the positions supported

by other group members. Informational influence has been

operationalized as statements revealing relevant facts or evidence

(e.g., Kaplan &Miller, 1987; Kelly, Jackson, & Hutson-Comeaux,

1997). In any decision-making group, both normative and informa-

tional influence can occur. Next we examine how normative and

informational influence may occur in hidden profiles.

SOURCES OF NORMATIVE INFLUENCE

In the context of hidden profiles, the initial starting positions

adopted by group members represents a possible source of norma-

tive influence. Statements that indicate the position favored by a

majority of group members should provide normative pressure on

Henningsen, Henningsen / NORMATIVE AND INFORMATIONAL INFLUENCE 393



other groupmembers to shift toward that position. Numerous stud-

ies have indicated that prediscussion positions favored by the

majority or a plurality have a strong influence on group decisions

(e.g., Gigone&Hastie, 1993;Gruenfeld et al., 1996;Kameda et al.,

1997; Larson et al., 1994; Stasser & Titus, 1985, 1987; Stewart

et al., 1998;Winquist&Larson, 1998). Based on previous research,

we argue that normative influence will be strongest when a clear

consensus exists among group members.

We argue that normative influence will be stronger in consensus

groups than in groups without initial consensus. In essence, when

there is an initial consensus, group members should face strong

normative pressure tomaintain the group harmony by not disagree-

ing with the clear group preference. Very little group discussion

may be necessary for group members to feel this normative pres-

sure. Evidence of normative pressure in groups with initial consen-

sus is evidenced by the fact that such groups are less likely to

change to the position most favored by the information (e.g.,

Hollingshead, 1996b). In addition to the prevalence of normative

influence in hidden profiles, informational influence should also

occur when group members rely on decision-relevant information.

In the next section, we examine informational influence in hidden

profiles.

SOURCES OF INFORMATIONAL INFLUENCE

Unshared information raised during discussion is a clear source

of informational influence. Unshared information represents new

facts or evidence for most of the group members that may be rele-

vant to the group decision. If the information is deemed accurate

and relevant, it has the potential to cause groupmembers to reevalu-

ate their positions to account for the new information. A variety of

studies have found that the presence of unshared information in the

group discussion can increase group decision-making accuracy

(Gigone & Hastie, 1997; Kelly et al., 1997; Larson et al., 1998;

Winquist & Larson, 1998).

In addition to unshared information, shared information in dis-

cussion should also exert informational influence. Mayer, Sonoda,




and Gudykunst (1997) found that groups with more decision-rele-

vant informationmade better decisions than groups with less infor-

mation in a context where all information was shared. This indi-

cates that, like unshared information, shared information can serve

as a source of informational influence. Consistent with past

operationalizations of informational influence (e.g., Kaplan &

Miller, 1987), raising an item of shared information in discussion

creates the potential for informational influence. When informa-

tion is shared prior to discussion, it can be incorporated into each

group member’s prediscussion decision preferences (Winquist &

Larson, 1998).However,when a shared item ismentionedor repeated

by another group member, that item has the potential to take on

greater weight in the decision-making process. When a group

member mentions an item of shared information, it can verify for

the other group members that they accurately recalled that item.

Furthermore, it can indicate that other members also consider that

item important and relevant to the decision-making process (see

Wittenbaum et al., 1999). This verification process may increase

theweight that groupmembers assign to shared items of information

and cause the members to readjust their preferences accordingly.

Evidence of shared information serving as a source of informa-

tional influence is available in several studies. Recall that Stasser

and Titus (1985) found that discussion decreased the percentage of

correct decisions among group members in hidden profile condi-

tions. They also found that group members recalled more shared

than unshared information after discussion when dealing with hid-

den profiles, indicating a preference for shared information in dis-

cussion. Larson, Christensen, et al. (1998) found that repetition of

shared information during discussion increased bias in decisions.

These studies indicate that the discussion of shared information

may have had an influence above and beyond the information’s

impact on group members’ initial preferences.

We have discussed how shared starting positions can create nor-

mative pressure in decision-making groups and how discussion of

shared and unshared information can create informational pres-

sure. In the next section,wewill consider how sources of normative

and informational influence are confounded in hidden profiles.




A CONFOUND IN HIDDEN PROFILES

In hidden profiles, the initial starting positions adopted by group

members and the information shared by group members are con-

founded. Each individual starts outwithmore shared than unshared

information. Shared and unshared information support different

decision alternatives, with shared information always favoring a

suboptimal decision alternative. Thus, both shared information and

the balance of prediscussion information support the inferior deci-

sion alternative. This sets up a situation inwhich it is difficult to dis-

tinguish the impact of shared information from the impact of initial

starting positions.

In addition, both informational and normative sources of influ-

ence favor the inferior decision alternative in hidden profiles,

whereas only the potential informational influence in the form of

unshared information favors the best alternative. In this study, we

attempt to extend hidden profile research by examining situations

inwhich the confound between shared information and initial start-

ing positions are reduced and reversed.We propose to do this while

maintaining a key aspect of hidden profiles. Specifically, in this

study, overall shared information and unshared information always

favor different alternatives.

In contrast to a hidden profile, an ambiguous profile is created

when information distribution does not create an initial preference

for either the best or the suboptimal decision alternative. In an

ambiguous profile, each group member starts with the same num-

ber of items favoring high- and low-quality decision alternatives.

The balance of shared information favors the less desirable deci-

sion alternative, and the balance of unshared information favors the

more desirable decision alternative. Therefore, in an ambiguous

profile, initial starting positions should be no more likely to favor

the position supported by shared information than the position sup-

ported by unshared information.

In a clear profile, the initial information distribution creates a

preference for the superior decision alternative. Opposite to the

classic hidden profile, in a clear profile, each group member starts

with more information favoring the superior than the inferior deci-

sion alternative. Consistent with hidden and ambiguous profiles,




the balance of shared information favors the inferior decision alter-

native and the balance of unshared information favors the superior

decision alternative in clear profiles. In the next sections, we pres-

ent ourhypotheses concerninghidden, ambiguous, andclearprofiles.

GROUP DECISION HYPOTHESIS

In conjunction with past research, we predict that under hidden

profile conditions, groups will choose the inferior decision alterna-

tive more frequently than the superior decision alternative (e.g.,

Cruz et al., 1997; Hollingshead, 1996b; Stasser & Titus, 1985).

This reflects the fact that both initial starting positions and shared

information favor the incorrect decision, whereas only unshared

information favors the correct decision.

With ambiguous profiles, we anticipate that groups will be more

likely to select the best decision alternative than under hidden pro-

file conditions. Here, shared information favors the poor decision

alternative and unshared information favors the best decision alter-

native. Initial starting position is neutral, thus reducing its potential

to influence decisions one way or the other.

In clear profile conditions, unshared information and initial

starting positions favor the best decision alternative. This reverses

the bias created in hidden profile conditions. Under these circum-

stances, wewould expect groups tomake the correct decisionmore

frequently than in the ambiguous or the hidden profile conditions.

Hypothesis 1: Groups with clear profiles will be more likely toselect the best alternative than groups with ambiguous profiles;groupswith ambiguous profileswill bemore likely to select the bestalternative than groups with hidden profiles.

NORMATIVE AND INFORMATIONAL INFLUENCE HYPOTHESES

The stronger the initial preferences are for a given position, the

more that initial starting positions will influence group decisions.

There are many examples of research indicating that the initial

starting positions of group members significantly predict group

decisions (e.g., Gigone & Hastie, 1993; Gruenfeld et al., 1996;




Kameda et al., 1997; Stasser & Titus, 1985, 1987; Stewart et al.,

1998). Social influence generated by the shared initial starting

positions of group members should take the form of normative

influence. The nature of hidden and clear profiles should lead

groups tomore prediscussion consensus thanwill occur in ambigu-

ous profiles. Thus, we feel that normative influence will be more

prevalent in hidden and clear profiles than in ambiguous profiles.

In contrast, when there is less initial support for a specific deci-

sion alternative, the use of normative influence should be reduced,

creating an opportunity for group members to use informational

influence. Some support for this contention is provided by research

that shows increased use of information by decision-making

groups with conflicting starting positions (Brodbeck et al., 2002;

Propp, 1997; but see also Gigone & Hastie, 1993; Stasser & Titus,

1985). Overall, we predict that groups will rely more on informa-

tional influence under ambiguous profiles than under clear or hid-

den profiles. Thus, we propose the following hypotheses:

Hypothesis 2:Group members will perceive more normative influ-ence in hidden and clear profile conditions than in ambiguous pro-file conditions.

Hypothesis 3: Group members will perceive more informationalinfluence in ambiguous profile conditions than in hidden and clearprofile conditions.

Various studies have shown that shared information is discussed

more than unshared information during group discussions of hid-

den profiles (e.g., Cruz et al., 1997; Hollingshead, 1996b; Savadori

et al., 2001). As noted previously, in hidden profiles, shared infor-

mation and initial starting positions favor the suboptimal decision

alternative.When a clear profile exists, the advantage of shared ini-

tial starting position should augment the position favored by

unshared rather than shared information. Dennis (1996) found that

groups were more likely to discuss information supporting their

initial positions than information thatwas negative or neutral to that

position (see also Schittekatte, 1996). Kelly and Karau (1999)

found that groupmembers were more likely to discuss information

that favored the best decision alternative if they initially preferred




that alternative. These studies indicate that initial preferences tend

to promote discussion of items supporting those preferences. In

clear profiles, that should lead to increased discussion of the

unshared information.

We have discussed how initial preferences lead to increased dis-

cussion of preference-consistent information. In addition, Boster

and Mayer (1984) found that arguments presented supporting the

majority position were considered to be stronger than arguments

offered supporting the minority position. Initial preferences seem

to addweight to shared information in hidden profile conditions but

should augment unshared information in clear profile conditions.

Thus, we propose our 4th hypothesis:

Hypothesis 4: Groups will favor shared information over unsharedinformation in hidden profile conditions, will equally favor sharedand unshared information under ambiguous profile conditions, andwill favor unshared information over shared information in clearprofile conditions.

Finally, becausewe are interested in social influence, wewant to

determine whether perceptions of normative and informational

influence are accurate predictors of actual social influence in

groups. To that end, we propose to examine how group members’

perceptions of normative and informational influence predict the

actual social influence that occurs during group decision making.

We propose the following hypothesis to examine this issue:

Hypothesis 5: Perceptions of normative and informational influ-encewill be positive predictors of shifts in groupmembers’decisionpreferences from pre- to postdiscussion.

METHOD

PARTICIPANTS

One hundred eleven undergraduates at a large midwestern uni-

versity (63 females, 43males, 5 unreported) were randomly assigned




to three-person groups (N = 37) to take part in the study. Partici-

pants were volunteers who received extra course credit for their

participation.

DESIGN

The design of the experiment was a three-group, one-way inde-

pendent groups design with random assignment to experimental

condition. The independent variable was the type of profile to

which groups were assigned: hidden profile, ambiguous profile, or

clear profile.

DECISION MATERIALS AND MEASURES

Decisionmaterials fromCruz et al. (1997)weremodified for use

in this study. The materials included the descriptions of two job

applicants for the position of assistant professor. Each description

focused on 14 characteristics of each professor (the same character-

istics for each). A criterion expressing the desired qualifications on

each of 14 items for the job applicant also was provided. Each item

of information either satisfied a criterion for a preferred candidate

(i.e., supporting information) or failed to satisfy a criterion for the

preferred candidate (i.e., opposing information). One additional

item was added to the Cruz et al. materials to accommodate three-

person groups.

Each group member received both shared and unshared infor-

mation representing a proportion of the total information about

each candidate. For each condition, the balance of shared informa-

tion favored the inferior decision alternative and the balance of

unshared information favored the superior decision alternative.

The information was distributed so that initial starting positions

favored (a) the suboptimal alternative in the hidden profile condi-

tion, (b) neither the optimal nor the suboptimal alternative in the

ambiguous profile condition, or (c) the optimal alternative in the

clear profile condition.

The amount of shared information in the information sets varied

slightly across conditions.We varied shared information so that we




would not have to add items or subtract items to/from any of the

conditions. In essence, to modify the number of unshared items of

information distributed to each group member, a net change of

three items of information was needed, whereas changing shared

information allowed for a change of only one item. Shared items

that were changed were randomly selected. The distribution of

shared and unshared items supporting or opposing either candidate

is presented in Table 1.

To measure social influence, sixteen 7-point, Likert-type items,

derived from Henningsen, Henningsen, Cruz, and Morrill (2002),

were used to measure perceived normative influence (e.g., “People

used their opinions to change other people’s minds,” “My behavior

was guided by a desire for group harmony”)withα = .71. Sixteen 7-point, Likert-type items derived from Henningsen et al. were also

used to assess perceived informational influence (e.g., “I thought

the groupmembers used information to swaymy decisions,” “Peo-

ple used their information to change other people’s minds”) with

α = .72.

PROCEDURES

After arriving at the laboratory, participants were randomly

assigned to three-person groups and to one of the three experimen-

tal conditions. Individuals were seated separately and were each

provided with a packet of information. The packet described a

hypothetical job search in which the participants were instructed to

role-play the part of a member of the search committee. A list of 14

criteria was explained in the packet. In addition, each person

received a description of two job candidates, including information

about how each candidate fit some of the 14 established criteria for

the position. Each group member received five items about each

candidate that was shared with all other group members and three

items that were held uniquely in themember’s group. After reading

the information contained in the packet, each group member indi-

vidually recorded his or her initial decision preference. Individuals

were then seated with their group members and instructed to dis-

cuss the decision task until they arrived at a consensus decision.




Following recording of the group decision, group members were

asked to list the items of information they felt were most important

to the decision that they made. Then, group members were again

separated, recorded their individual preferences, and filled out the

normative and informational influence questionnaires. On com-

pleting the questionnaires, participants were debriefed and

released.

RESULTS

MANIPULATION CHECKS

To ensure that the profile manipulation was successful, a series

of χ2 tests were performed using individual prediscussion prefer-


TABLE 1: Shared andUnshared Information Favoring theOptimal and Suboptimal

Decision Alternatives

Applicant Shared Information Unshared Information

Optimal alternative

Hidden profile

Items supporting 0 9

Items opposing 5 0

Ambiguous profile


Items opposing 4 0

Clear profile


Items opposing 3 0

Suboptimal alternative

Hidden profile


Items opposing 0 9

Ambiguous profile


Items opposing 1 9

Clear profile


Items opposing 2 9

NOTE: All shared items are held by all group members. Unshared items are divided equallyamong group members.



ences. Under hidden profiles, we expected group members to pre-

fer the inferior decision alternative. For the hidden profile condi-

tion, χ2 (1) = 11.11, p < .01. Of 36 individuals provided with thehidden profile, 28 chose the inferior decision alternative, indicating

that the hidden profile successfully biased initial preferences in

favor of the suboptimal decision alternative.

We expected individuals under ambiguous profiles to show no

clear preference for the superior or the inferior decision alternative.

For the ambiguous profile conditions, χ2 (1) = 2.08, p = .11. Of 39individuals provided with the ambiguous profile, 15 selected the

best decision alternative and 24 selected the inferior decision alter-

native. The finding that this difference is not significant supports

our contention that the ambiguous profile condition did not provide

a clear bias for either candidate.

Finally,we anticipated that groups under clear profile conditions

would initially favor the best decision alternative over the lesser

decision alternative. For the clear profile conditions, χ2 (1) = 7.11,p < .01. Of 36 individuals with a clear profile, 26 selected the best

decision alternative and only 10 selected the lesser decision alter-

native. Again, this supports our contention that the clear profile cre-

ated a bias favoring the best decision alternative.

TESTS OF HYPOTHESES

In Hypothesis 1, we predicted that groups would be most likely

tomake the correct decision in the clear profile groups, less likely to

make the correct decision in the ambiguous profile groups, and

least likely tomake the correct decision in hidden profile groups. To

test these predictions, we used a one-way ANOVA design using

type of profile (hidden, ambiguous, or clear) as the independent

variable and group decision (correct decision = 1; incorrect deci-

sion = 2) as the dependent variable. To test the hypothesis, we

examined a planned contrast model that tested the linear contrast

(see Table 2 for means and standard deviations). We conducted a

contrast analysis because it allowed us to test the specific pattern of

means predicted inHypothesis 1.A significant contrastmodel indi-

cates that our hypothesis did accurately predict our findings. A




nonsignificant residual variance indicates that we did not overlook

any nonhypothesized significant effects.

The linear contrast model was significant, F(1, 37) = 15.02, p <

.01,η2 = .30,whereas the residual variancewas not significant,F(1,

37) = .12, p < .01, η2 < .01. Thus, Hypothesis 1 was supported.

Groups were most likely to select the best decision alternative

under clear profiles and were least likely to do so under hidden

profiles.

In Hypothesis 2, we predicted that groups would perceive more

normative influence in hidden and clear profile conditions than in

ambiguous profile conditions. Again, a planned contrast was per-

formed to determinewhether the hypothesized quadratic effectwas

supported (see Table 3 for means and standard deviations). Neither

the contrast model, F(1, 37) = 2.75, p = .11, η2 = .07, nor the resid-

ual variance, F(1, 37) = .09, p > .10, η2 < .01, was significant.

Therefore, we conclude that Hypothesis 2 is not supported.

In Hypothesis 3, we predicted that group members would per-

ceivemore informational influence in the ambiguous profile condi-

tion than in the hidden or clear profile conditions. A planned con-

trast analysis of the hypothesized quadratic effectwas performed to

test this prediction (see Table 4 for means and standard deviations).

The contrast model was significant, F(1, 37) = 3.94, p = .05, η2 =

.10, whereas the residual variance was not significant, F(1, 37) =

.03, p > .10, η2 < .01. Thus, Hypothesis 3 was supported. Group

members perceived more informational influence under ambigu-

ous profiles than under either of the other conditions.

We predicted in Hypothesis 4 that reliance on shared informa-

tion would be highest in hidden profiles and would be reduced as

groupsmoved to ambiguous and clear profiles. Conversely, we pre-

dicted that reliance on unshared information would steadily


TABLE 2: Means and Standard Deviations for Group Decision Contrast Model

M SD n

Hidden profile 1.92 .29 12

Ambiguous profile 1.62 .51 13

Clear profile 1.25 .50 12



increase from hidden profiles to ambiguous profiles to clear pro-

files. A planned contrast model was designed to test the linear

effects proposed in Hypothesis 4 (see Table 5 for means and stan-

dard deviations). To determine how much reliance groups placed

on shared or unshared information, each group recorded the items

of information they felt were most influential to their groups in

making the decision. These itemswere coded as shared or unshared

based on the distribution of information in each group. The number

of items of shared and unshared information each group reported

they relied on were used as a measure of that group’s reliance on

each type of information. Type of information (shared or unshared)

is a within-group variable, and the decision condition (hidden,

ambiguous, or clear profile) is a between-group variable. Overall,

the contrast model was significant, F(1, 37) = 13.57, p < .01, η2 =

.26, and the residual was not significant,F(1, 37) = .09, p> .10,η2 <

.01. This supports Hypothesis 4. The reliance on shared informa-

tion over unshared information in hidden profiles is reversed under

clear profiles.

REGRESSION ANALYSIS

To further examine the relationship between normative and

informational influence in decision-making contexts, we calcu-


TABLE 3: Means andStandardDeviations forNormative InfluenceContrastModel

M SD n




TABLE 4: MeansandStandardDeviations for Informational InfluenceContrastModel

M SD n






lated the correlation between normative and informational influ-

ence. The correlationwas significant and positive, r= .41, p= .01.

We were also interested in exploring the overall effect that nor-

mative and informational influence had on social influence in

groups. InHypothesis 5, we predicted both normative and informa-

tional influencewould positively effect changes in groupmembers’

preferences. We calculated a measure of overall influence in the

decision-making groups by subtracting the number of group mem-

bers expressing a preference for the best alternative after discussion

from the number of group members initially expressing a prefer-

ence for the best alternative in each group. Taking the absolute

value of this number gives us a measure of how many group mem-

bers changed positions during group discussion. This is a good

indicator of the overall social influence that occurred during group

discussions.We regressed thismeasure of social influence onto our

measures of perceived normative and informational influence. The

multiple regression coefficient for this regression was significant,

R= .63,R2 = .40, p< .01. Although the partial regression coefficient

for normative influence was not significant, β = –.05, p > .10, thepartial regression coefficient for informational influence was posi-

tive and significant, β = .65, p < .01. This indicates that the socialinfluence that occurred in the group decisions tended to be per-

ceived as more informational than normative and provides partial

support for Hypothesis 5.


TABLE 5: Means and Standard Deviations for Shared and Unshared Information

Contrast Model

M SD

Shared information

Hidden profile .50 .90

Ambiguous profile 1.46 1.26

Clear profile 1.83 1.83

Unshared information

Hidden profile 2.25 1.13

Ambiguous profile 1.38 1.19

Clear profile .66 .65



DISCUSSION

In this study, we began with the proposition that the effect of

shared information and initial starting positions are confounded in

hidden profiles because both favor a suboptimal decision alterna-

tive.Weproposed that groupswouldmake significantly better deci-

sions under ambiguous and clear profiles than under hidden pro-

files. Overall, we found support for this position. Groups moved

from inferior to superior decisions as they moved from hidden pro-

files to clear profiles.

We also predicted that normative influence would be more prev-

alent in groups with hidden and clear profiles than in groups with

ambiguous profiles. This hypothesis was not supported. No signifi-

cant differences existed across conditions for perceptions of nor-

mative influence. In contrast, as hypothesized, significantly more

informational influence was perceived in the ambiguous profile

condition than in the hidden and clear profile conditions. This find-

ing was consistent with our predictions.

We also found support for our hypothesis that groups’ reliance

on shared informationwas greatest in hidden profile conditions and

lowest in clear profile conditions, while the reverse held true for

reliance on unshared information. It appears that coupling shared

starting positions with either shared or unshared information tends

to increase the weight that information has in group decisions. This

is consistent with Boster and Mayer’s (1984) finding that argu-

ments from majorities are perceived as stronger than arguments

coming from minority positions within groups. When the

prediscussionmajority favors the best decision, the groupmembers

are more likely to rely on information that supports that decision

(i.e., unshared information). However, when the prediscussion

majority favors the inferior decision, the group members are more

likely to rely on the subset of information favoring the inferior deci-

sion (i.e., shared information). Thus, the weight accorded to items

of information is influenced by prediscussion support for the posi-

tion that information supports.

Perhaps the most intriguing result from this study is the finding

that perceptions of informational influence are a better predictor of




overall influence than perceptions of normative influence. This

seems counter to the findings of Cruz, Henningsen, and Williams

(2000), in which normative statements had a greater influence than

informational statements on individual decisions. One reason for

this may be due to how Cruz et al. operationalized normative influ-

ence. Cruz et al. used recasting statements tomanipulate normative

influence. Recasting occurs when a groupmember either discounts

(i.e., diminishes the importance) or bolsters (i.e., emphasizes the

importance) an item of information. Thus, a person engages in

recasting in a group when he or she discusses the importance (or

lack thereof) of an item of information rather than simply mention-

ing the item. In essence, recasting reflects how group members try

to influence how much weight an item of information should hold

for the group decision.

As Cruz et al. (2000) noted, recasting could serve as a source of

normative or informational influence. By addressing the weight

that should be given a piece of information, a group member indi-

cates the position he or she supports and thus may apply normative

influence. However, inferences drawn about information are indi-

cated when information is recast. For instance, Cruz et al. (1997)

offered the following example of discounting. A group member

argues that the high teaching ratings of a job candidate are more an

indicator that the candidate was an easy grader than an indicator

that the candidate was a good teacher. In this example, another

group member may recognize the speaker opposed a specific can-

didate (the candidate with better evaluations). However, the other

groupmembers alsomay consider the claim that good teaching rat-

ings are the result of easy grading as information relevant to the

decision. Thus, recastingmay be perceived as informational or nor-

mative influence.

It may also be that normative influence was reduced in the pres-

ent study because we used three-member groups. Asch (1955)

found a substantial increase in social influence for individuals fac-

ing a 3-to-1 majority compared to a 2-to-1 majority. It is possible

that in using smaller groups, we reduced the potential for group

members to successfully exert normative influence. In Cruz et al.




(2000), individuals potentially could face consistent pressure from

all four members of the hypothetical group.

LIMITATIONS AND FUTURE DIRECTIONS FOR RESEARCH

How recasting is interpreted by individuals in decision-making

groups presents a limitation of this study. Namely, we did not

record group discussions and so we were unable to look at the rela-

tionship between statements of information, statements of prefer-

ence, and recasting statements and our perceptual measures of nor-

mative and informational influence. Clearly, such data would be

beneficial to a fuller understanding of normative and informational

influence and is a clear direction for future research.

As it is, we feel that we have made a significant contribution to

the hidden profile literature. For the first time, to our knowledge, an

information distribution in which initial preferences coincided

with unshared rather than shared information was examined. The

creation of a clear profile offers conditions under which reliance on

unshared information exceeds reliance on shared information in

decision-making groups. This provides a clearer understanding of

why shared information is favored in hidden profile conditions.We

have found that the nature of a profile has a strong effect on (a) deci-

sions made by group members, (b) perceptions of informational

influence, and (c) reliance on shared and unshared information dur-

ing group decision making.

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David Dryden Henningsen (J.D., 1992; Ph.D., 1999, University of Wisconsin) is

assistant professor in the Department of Communication at Northern Illinois Uni-

versity. He has active lines of research looking at both group decision making and

interpersonal relationships. Across both lines of research he is interested in how nor-

mative and informational processes influence human behavior. His research has

touched on decision making, flirting, and deception.

Mary Lynn Miller Henningsen (Ph.D., 2001, University of Wisconsin) is assistant

professor in the Department of Communication at Northern Illinois University. Her

research focuses on message evaluation in social influence and interpersonal con-

texts. In particular, it has focused on small group decision-making interactions and

date initiation.




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Examining Social Influence in Information-Sharing Contexts