Karlyn E. VatthauerCollege of Arts & Science, Department of

Psychology, & Honors CollegeMentor: Dr. Daniel Taylor, Ph.D., Department of

Psychology, UNT

Research TopicThe predictive relationship of sleep and

academic performance (GPA).

VocabularyTraditional - variables that have commonly

been shown to predict academic performance in previous researchHigh school GPA, standardized test scores,

ethnicity, gender, socioeconomic statusModifiable - variables that may be amenable to

treatment to increase academic performanceAlcohol/drug use, alcohol/drug disorder,

anxiety, depression, sleep

PurposeThe intention of this project was to compare

traditional and modifiable variables, specifically sleep, as predictors of GPA (cumulative & semester*).

* Data not shown in this presentation

Research QuestionsIs sleep significantly correlated with GPA?

If yes, in what way?Is sleep a significant predictor of GPA when

other variables are accounted for?

Literature ReviewSeveral studies have shown a positive

correlation between undergraduate academic performance (GPA) and postgraduate earnings (Filer 1981, 1983; Jones & Jackson, 1990; Pascarella & Terenzini, 2003; Wise, 1975).

Colleges and universities rely very heavily on standardized test scores and high school grades to predict GPA.

Literature Review When combined, HS GPA and standardized test

scores only predict 25 % of GPA variance (ACT, 1997; Boldt, 1986; Mathiasen, 1984; Mouw & Khanna).

In previous studies, gender, ethnicity, and socioeconomic status (SES) have predicted GPA (Betts & Morell, 1999; Peters, Joireman, & Ridgway, 2005).

Literature ReviewResearch has shown mixed results (negative

relationship or no relationship) for alcohol use as a predictor of GPA (Paschall & Freisthler, 2003; Singleton, 2007).

Chronic drug use leads to cognitive impairments on achievement tests (Block, Erwin, & Ghoneim, 2002; Hoshi, Mullins, Boundy, Brignell, Piccini, & Curran, 2007; Solowij et al., 2002).

Literature ReviewPrevious and current research has shown a

positive relationship between anxiety disorders and GPA (Stringer, Crown, Lucas, & Supramanium, 1977).

Research has yet to show whether a relationship exists between depression and GPA (Hysenbegasi, 2005; Svanum & Zody, 2001).

Literature ReviewResearch of sleep patterns and academic

performance has been very limited.Most researchers use total sleep time to study

differences in sleep patterns (Gau et. al, 2007; Peters et al., 2005; Thacher, 2008).

There are many other sleep variables that can be studied:Time in bed, sleep efficiency, sleep onset

latency, wake after sleep onset, time awake in morning, nap time, and number of awakenings

Literature ReviewSleep problems are a frequent occurrence within

the college population (Forquer, Camden, Gabriau, & Johnson, 2008).

These problems should affect more than the bedroom.

HypothesesSleep pattern will be significantly correlated with

GPA because it is a primary part of students’ lifestyles.Specifically, sleep onset latency, wake time

after sleep onset, and time awake in morning will predict GPA.

Sleep pattern will significantly predict GPA when all variables are accounted for.

Sleep pattern will significantly predict GPA when traditional variables are removed.

MethodsParticipants (N = 951) were recruited from

undergraduate psychology classes at the University of North Texas.

Participants completed a self-report health questionnaire packet and a week long sleep diary, available on the SONA system, an online research service.

Students received four extra credit points towards their psychology class.

Methods Demographics

74% were femalesEthnicity

63% Caucasian 13% African-American 10% Hispanic-American 5% Asian/Pacific-Islander 1% Native American 4% other

Academic rank 40% freshmen 27% sophomores 19% juniors 15% seniors

Age (M = 20.3; SD = 3.9).Family income ( Mean = $100,000 - $149,000 (SD = 2.9)

Data AnalysisMultiple correlation

Sleep pattern variables and GPA All other variables and GPA*

Stepwise multiple regression Significant correlates and GPA**Significant modifiable variables and GPA

*Data not shown in this presentation

**Only sleep pattern variables shown

ResultsMultiple correlation of sleep pattern and GPA

Significant relationship between GPA and:Sleep onset latency (r = -.06, p < .05)Nap time (r = -.11, p < .01)Number of awakenings (r = .08, p < .05)

Table 1

Summary of Stepwise Multiple Regression Analysis with Significant

Correlates as Criterion

Step Predictor Variable R² R² F β

6 NWAK .18 .01 5.93* .10**

7 NAP .19 .01 6.42* -.08*

Note. NWAK = Number of Wakenings; NAP = Nap Time; PSS =

Perceived stress scale

 

*p < .05. **p < .01.  

Table 2

Summary of Stepwise Multiple Regression Analysis with Significant Intervention-

Possible Correlates as Criterion

Step Predictor Variable R² R² F β

1 AUDIT .02 .02 20.26** -.12**

2 NAP .03 .01 11.44** -.11**

3 PSS .04 .01 9.20** -.11**

4 NWAK .06 .01 10.02** .11**

5 MPS .06 .01 5.07* -.08 *

Note. AUDIT = Alcohol use disorders identification test; NAP = Nap Time; PSS =

Perceived stress scale; NWAK = Number of Wakenings; MPS = Marijuana

problem scale. *p < .05. **p < .01.

DiscussionSleep pattern was significantly correlated with

GPA.Specifically, sleep onset latency, nap time,

and number of awakenings.Nap time and number of awakenings continued

to be significant predictors of GPA after accounting for all other variablesEach accounted for an additional 1% of GPA

variance.

DiscussionOverall, of modifiable variables:

Sleep variables accounted for 2% of GPA variance

Alcohol use disorders 2%Trait stress 1% Marijuana use 1%

AcknowledgementsDr. Daniel Taylor, PsychologyDr. Susan Eve, Associate Dean of the Honors

CollegeDr. Gloria Cox, Dean of the Honors CollegeDepartment of PsychologyCollege of Arts and Science

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