Age, the Big Five, and time-of-day preference: A mediational model

•Older participants expressed a morning preference.•Conscientious and agreeable participants expressed a morning preference.•Open, neurotic, and extraverted participants expressed an evening preference.•Conscientiousness attenuated the association between age and time of day preference.

This research examined the extent to which the Big Five personality factors mediated the relationship between age and time-of-day preference. A sample of 491 Americans (Mage = 32 yrs) completed the 240-item NEO-PI-R, the 19-item Horne and Östberg’s (1976) Morningness–Eveningness Questionnaire (MEQ), and provided demographic information. As demonstrated in previous research, correlations revealed that older people expressed a stronger morning preference. More importantly, using bootstrapping procedures, it was found that the Big Five factor of conscientiousness attenuated the relationship between age and time-of-day preference. These findings indicate that conscientiousness plays a significant role in the relationship between age and time-of-day preference.