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

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 (M_age = 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.     

Longitudinal predictors of changes in the morningness–eveningness personality among Norwegian nurses

The aim of this cohort study was to investigate factors that might cause a shift in morningness–eveningness personality. A large sample of Norwegian nurses (n = 1144) participated in a longitudinal survey study about life- and work factors, symptoms of anxiety and depression, and habits such as smoking, caffeine- and alcohol consumption. A hierarchical regression analysis was employed to determine if these variables had predictive value concerning changes in morningness assessed with the Diurnal Type Scale (DTS) over a 24-month interval. The results showed that percentage of full time equivalent, having children (or having children move in), and female gender all predicted higher scores on the morningness scale over time. Also, factors such as number of night shifts during the past two years, whether the subject had started smoking and higher alcohol consumption by the subject all predicted lower scores on the morningness scale over time.     

Conscientiousness but not agreeableness mediates females’ tendency toward being a morning person

Individuals differ in their chronotype, and some are identified as morning ones and others as evening ones. Earlier studies showed that women were higher on morningness, conscientiousness, and agreeableness. In this study, we aimed at exploring the mediational effects of conscientiousness and agreeableness in the relationship of gender and morningness‐eveningness. Participants were 669 university students. Results supported positive relationships between morningness and conscientiousness and agreeableness and between conscientiousness and agreeableness. Females were higher on all these three variables. Mediation analyses suggested that the effect of gender (here females) on chronotype (here morningness) was mediated by conscientiousness but not agreeableness so that after the mediation partially occurred, the gender's effect did not remain significant anymore. This study backed our hypothesis that conscientiousness might play a more pronounced role than the intrinsic diurnal rhythm concerning the sex differences in chronotype.     

Predicting students’ learning strategies: The contribution of chronotype over personality

Students’ learning strategies as well as the search for its determinants have gained expanding interest in psychology and educational research. The present study investigated the contribution of chronotype, another construct of increasing importance in the academic context, to students’ learning strategies controlling for the established predictor of personality and its relations to chronotype. A sample of 318 college students (mean age = 22.6, SD = 2.5; age range = 19–34) was assessed online through self-report questionnaires. We discriminated between two learning strategy factors aggregated by a diverse set of learning strategies, learning discipline and elaboration. First, results confirmed significant associations between most personality scales and students’ strategy use. Furthermore, we found evidence for significant associations between chronotype and personality, as well as chronotype and learning strategies. Finally, structural equation modeling revealed that openness, agreeableness, conscientiousness, and morningness were significant predictors for elaboration, whereas learning discipline was significantly predicted by conscientiousness and morningness. We conclude that chronotype plays an important role explaining students’ learning strategies over and above personality.     

The stability of the morning affect scale across age and gender

A limitation of the morningness–eveningness literature is the assumption that morningness is a ‘fixed’ construct. Morningness–eveningness scales are often developed on young adult samples, yet studies report that eveningness peaks in young adults with a shift to morningness from the age of 25 to 35 years of age. This age related change in morningness–eveningness may explain why these scales have limited success when applied in older samples. We tested this argument by developing a measurement model based on the Composite Scale of Morningness using a sample aged <30 years of age. Tucker’s congruence coefficient and confirmatory factor analysis indicated this solution was not a good fit in three older age groups. In contrast, we repeated this assessment using the ‘morning affect’ scale. This scale comprises items that measure morningness preference only. Model fit indicators suggested the ‘morning affect’ scale was a good fit across four age groups and gender.     

Morningness-eveningness, use of stimulants, and minor psychiatric disorders among undergraduate students

Morningness–eveningness dimension in humans have been indicated to influence social behavior and individual health. The aim of the present study was to investigate the association of the morningness–eveningness dimension with behavioral and health aspects in a sample of undergraduate students. We assessed demographic data; the Pittsburgh Sleep Quality Index was used to evaluate sleep quality; the Morningness/Eveningness Questionnaire to determine morningness–eveningness, and the Self‐Reporting Questionnaire to assess minor psychiatric disorders. A total of 372 students (66.7% females), on average 21.6 years old, participated in this study. Among them, 92.2% did not smoke, 58.9% engaged in physical activities, and 19.7% were night‐shift workers. In regard to morningness–eveningness, 55.9% of the participants were intermediate between evening (39.5%) and morning (4.6%) types. Poor sleep quality (OR = 1.89), minor psychiatric disorders (OR = 1.92), and tobacco consumption (OR = 3.65) predominated among evening types. Evening types were predominantly males (OR = 1.72). This study suggests that evening types are more vulnerable to sleep and psychiatric disturbances, and tend to smoke more than morning types.     

Creatures of the night: Chronotypes and the Dark Triad traits

In this study (N = 263) we provide a basic test of a niche-specialization hypothesis of the Dark Triad (i.e., narcissism, psychopathy, and Machiavellianism). We propose that in order to best enact a “cheater strategy” those high on the Dark Triad traits should have optimal cognitive performance and, thus, have a night-time chronotype. Such a disposition will take advantage of the low light, the limited monitoring, and the lessened cognitive processing of morning-type people. The Dark Triad composite was correlated with an eveningness disposition. This link worked through links with the “darker” aspects of the Dark Triad (i.e., Machiavellianism, secondary psychopathy, and exploitive narcissism); correlations that were invariant across the sexes. While we replicated sex differences in the Dark Triad, we failed to replicate sex differences in chronotype, suggesting eveningness may not be a sexually selected trait as some have argued but is a trait under natural selective pressures to enable effective exploitations of conspecifics by both sexes.