Previous research suggests a possible link between eveningness and general difficulties with self-regulation (e.g., evening types are more likely than other chronotypes to have irregular sleep schedules and social rhythms and use substances). Our study investigated the relationship between eveningness and self-regulation by using two standardized measures of self-regulation: the Self-Control Scale and the Procrastination Scale. We predicted that an eveningness preference would be associated with poorer self-control and greater procrastination than would an intermediate or morningness preference. Participants were 308 psychology students (mean age=19.92 yrs) at a small Canadian college. Students completed the self-regulation questionnaires and Morningness/Eveningness Questionnaire (MEQ) online. The mean MEQ score was 46.69 (SD=8.20), which is intermediate between morningness and eveningness. MEQ scores ranged from definite morningness to definite eveningness, but the dispersion of scores was skewed toward more eveningness. Pearson and partial correlations (controlling for age) were used to assess the relationship between MEQ score and the Self-Control Scale (global score and 5 subscale scores) and Procrastination Scale (global score). All correlations were significant. The magnitude of the effects was medium for all measures except one of the Self-Control subscales, which was small. A multiple regression analysis to predict MEQ score using the Self-Control Scale (global score), Procrastination Scale, and age as predictors indicated the Self-Control Scale was a significant predictor (accounting for 20% of the variance). A multiple regression analysis to predict MEQ scores using the five subscales of the Self-Control Scale and age as predictors showed the subscales for reliability and work ethic were significant predictors (accounting for 33% of the variance). Our study showed a relationship between eveningness and low self-control, but it did not address whether the relationship is a causal one.
