Sleep-length and life satisfaction in a college student sample
William E. Kelly
The relationship between sleep-length and global life satisfaction was investigated among a sample of 212 college students. Participants indicated their habitual sleep-length and completed the Satisfaction with Life Scale. Results of a simple regression indicated that individuals who reported habitually attaining less sleep were also significantly likely to report lower life satisfaction. The results and directions for future research are discussed.
According to previous research individuals who attain less sleep, when compared to those who attain more sleep, tend to be less psychologically healthy. For instance, college students who attain less sleep report more neuroticism (Kumar & Vaidya, 1982), anxiety (Kumar & Vaidya, 1984), worry (Kelly, 2002) and hallucinations (Soper, Kelly, & Von Bergen, 1997). They also tend to report less creativity (Hicks, Guista, Schretlen, & Pellegrini, 1980) and lower grade-point averages (Kelly, Kelly, & Clanton, 2001).
Many of the variables associated with sleep-length are also related to satisfaction with life. For example, previous research indicates that individuals who are less satisfied with life report higher levels of anxiety (Headey, Kelley, & Wearing, 1993), worry, and neuroticism (Chang, 2000).
Based on their common relationships with other variables, it could be speculated that sleep-length and life satisfaction are related. However, no published empirical research examines this possibility. The purpose of this study, therefore, is to examine the relationship between sleep-length and life satisfaction. Based on the shared unpleasant psychological experiences between individuals experiencing lower levels of both these variables, it was predicted that sleep-length would be positively related to life satisfaction.
Participants and Procedure
After obtaining informed consent, 171 females and 41 males (M age = 24.6, SD = 7.0) enrolled in undergraduate psychology and graduate counseling courses were administered the self-report surveys described below. The average age of the sample was 26.9 (SD = 8.9).
Sleep-Length. Sleep-length estimates were self-reported as a continuous variable by using the method of Kumar & Vaidya (1984), whereby participants were asked to write the amount of time, hours and minutes, they habitually sleep, on average, in a 24-hour period.
Life Satisfaction. Life satisfaction was measured using the 5-item Satisfaction with Life Scale (SWLS; Diener, Emmons, Larsen, & Griffin, 1985), a measure of global life satisfaction. Individuals responded to items using a 7-point Likert scale ranging from 1 = “strongly disagree” to 7 = “strongly agree.” Responses were summed to produce a total SWLS score, with higher scores indicating more life satisfaction. Internal consistency (.87), test-retest reliability (.82, eight weeks), and validity of the SWLS are good (Diener et al., 1985).
RESULTS AND DISCUSSION
The average sleep-length reported by the sample was 6.96 (SD = 1.92) hours per 24-hour period. The mean, standard deviation, and Coefficient Alpha of the SWLS in the current sample were: 23.6, 6.5, and .82, respectively. Age did not significantly correlate with sleep-length, r = -.04, or SWLS scores, r = .03. There were no significant differences between males and females for sleep-length, t (210) = .744, or SWLS scores, t (210) =. 16. Hence, data were collapsed across sex and analyzed irrespective of age.
A simple regression was calculated using sleep-length as the criterion and SWLS scores as the predictor. The result was significant, F(1,210) = 12.3,p < .001, with SWLS scores accounting for 5.5% of the variance in sleep-length. Consistent with the hypothesis, the beta weight, revealed a positive relationship; attaining less sleep was associated with less life satisfaction, [beta] = .24.
Overall, the result of this study is consistent with previous research suggesting that college students who attain less sleep tend to be less psychologically healthy (see review above). A causal direction for these results cannot be determined. However, it might be speculated that the unpleasant psychological experiences of habitually short-sleepers may result in individuals perceiving their lives as less than satisfactory. Alternatively, it is possible that individuals that attain less sleep also have a general pessimistic, neurotic temperament, which in turn, influences their perception that they experience many unpleasant psychological symptoms. Additional research is required to examine: these possibilities. Also, specific situations at bedtime may influence both decreased sleep and less life satisfaction. For instance, Kelly (2003, Study 1) found that individuals who reported less life satisfaction also tended to attribute difficulty sleeping to the experience of worry. Additional research is needed to evaluate the role of disruptive sleep experiences in the relationship between sleep-length and life satisfaction.
Chang, E. C. (2000). Perfectionism as a predictor of positive and negative psychological outcomes: Examining a mediation model in younger and older adults. Journal of Counseling Psychology, 47, 18-26.
Diener, E., Emmons, R. A., Larsen, R. J., & Griffin, S. (1985). The Satisfaction With Life Scale. Journal of Personality Assessment, 49, 71-75.
Headey, B. W., Kelley, J., & Wearing, A. J. (1993). Dimensions of mental health: Life satisfaction, positive affect, anxiety, and depression. Social Indicators Research, 29, 63-82.
Hicks, R. A., Guista M., Schretlen, D., & Pellegrini, R. J. (1980). Habitual duration of sleep and divergent thinking. Psychological Reports, 46, 426.
Kelly, W. E. (2002). Worry and Sleep Length Revisited: Worry, Sleep Length, and Sleep Disturbance Ascribed to Worry. Journal of Genetic Psychology, 163, 296-304.
Kelly, W. E. (2003). Some correlates of sleep disturbance ascribed to worry. Individual Differences Research, 1, 137-146.
Kelly, W. E., Kelly, K. E., & Clanton, R. C. (2001). The relationship between sleep length and grade-point average among college students. College Student Journal, 35, 84-86.
Kumar, A., & Vaidya, A. K. (1982). Neuroticism in short and long sleepers. Perceptual and Motor Skills, 54, 962.
Kumar, A., & Vaidya, A. K. (1984). Anxiety as a personality dimension of short and long sleepers. Journal of Clinical Psychology, 40, 197-198.
Soper, B., Kelly, W. E., & Von Bergen, C. W. (1997). A preliminary study of sleep length and hallucinations in a college student population. College Student Journal, 31, 272-275.
WILLIAM E. KELLY
Individual Differences Research Group
P.O. Box 201073
Austin, Texas 78720-1073
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