Circadian preference and perceived quality of the sleep/wake cycle in Italian high school students

We explored the relationship between circadian preference and perceived quality of the sleep/wake cycle in Italian high school students aged between 14 and 18 years. Three hundred and forty-five participants (299 females, 46 males) were administered the Morningness–Eveningness Questionnaire for Children and Adolescents (MEQ-CA) and the Mini Sleep Questionnaire (MSQ) to determine circadian preference and subjective quality of the sleep/wake cycle, respectively. The MSQ includes two main factors: sleep and wake; lower scores on these two factors correspond to a poorer quality of sleep and wake. Evening-type adolescents scored significantly lower than morning types on the wake factor. No significant effect of circadian preference was observed regarding the sleep factor. Our results suggest that Eveningness preference is significantly and negatively related to the perceived quality of the wake factor of Italian high school students.     

Cross‐cultural comparison of seven morningness and sleep–wake measures from Germany,India and Slovakia

Morningness–eveningness or circadian typology can be viewed as an interesting aspect of individual differences. Morningness–eveningness is a preference for a given time of day for physical or mental performance, but also reflects aspects of affect. Here, we used seven different measures to assess differences in morningness–eveningness between Germany, Slovakia and India. The hypothesis was that Indians should be earliest chronotypes, followed by Slovakia and then Germany, because of higher temperatures in India, and the fact that Slovakia is located farther east compared to Germany. We applied the Composite Scale of Morningness (CSM), the Circadian Energy Scale (CIRENS), the CAEN Chronotype Questionnaire (CCQ), and habitual sleep–wake variables to calculate sleep duration, midpoint of sleep and social jetlag. Sample sizes were N = 300 (Germany), N = 482 (Slovakia) and N = 409 (India). Country had the strongest influence on morningness–eveningness. Germans were latest chronotypes and differed in all seven measures from Indians but differed from Slovakians only in the energy level at the evening and midpoint of sleep. Slovakians and Indians differed in all measures but the energy level (CIRENS). Women scored higher on the CSM, lower on CIRENS, lower on the morningness–eveningness (ME) scale, but higher on distinctness (DI) scale. Women slept longer and had an earlier midpoint of sleep.     

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.     

日周期类型与心理健康

个体间表现出的昼夜节律差异现象可以从日周期类型上进行分类, 包括偏爱早睡早起的清晨型, 偏爱晚睡晚起的夜晚型以及处于两者之间的中间型。已有研究表明, 夜晚型与心境障碍、注意缺陷多动障碍和进食障碍等心理疾病有关, 而日周期类型与心理健康的关系可能受到基因、社会时差、人格等因素的影响。未来应改进研究设计和测量方法, 深入考察日周期类型与心理健康的关系及其作用机制, 以及在我国文化背景下推进日周期类型与心理健康的关系研究。     

Effects of longitude,latitude and social factors on chronotype in Turkish students

The aim of this research was to investigate whether morningness–eveningness, midpoint of sleep and average sleep duration are associated with longitude, latitude, age, gender, inhabitation and school start times in Turkish students. 15,362 students from 9 to 21 years participated in this study. Eveningness and midpoint of sleep – but not sleep duration – increased from east to west, suggesting that longitude has an effect on chronotype. Adolescents from the southern parts of Turkey were more morning oriented, suggesting an influence of climate or latitude. Morningness was negatively and midpoint of sleep was positively related with age. Females had higher morningness scores and students from urban localities showed higher eveningness and a later midpoint of sleep.     

Morningness in German and Spanish students: a comparative study

Humans show pronounced individual differences in circadian orientation. Transcultural comparisons are interesting since biological (or environmental) factors together with cultural ones may contribute to differences in morningness–eveningness. We compared Spanish and German undergraduates using the Composite Scale of Morningness (CSM) to assess circadian preferences. Confirmatory and multiple groups confirmatory factor analysis were used to assess factor structure and structural invariance across countries. The results showed that a three‐factor model of morningness best characterises the CSM structure of both samples. Partial factorial invariance (factor loadings) across countries was demonstrated for the factors ‘morningness’ and ‘morning alertness’. Scores of both factors were higher in German students. Potential cultural and biological explanations for the differences are discussed. Copyright © 2007 John Wiley & Sons, Ltd.     

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.     

Effect of personality dimensions on the diurnal pattern of motor activity

The effects of personality dimensions, age, and gender on 24-hour motor activity patterns were studied in 101 healthy subjects between 20-70 years. We measured motor activity by wrist-actigraphy and personality dimensions by the Tridimensional Personality Questionnaire (TPQ) of Cloninger. Random Regression Models were used to estimate the effects of personality dimensions, age, and gender on the diurnal pattern of motor activity. Harm Avoidance as well as Reward Dependence influenced the overall level of motor activity, independent of age and gender. Subjects high on Harm Avoidance showed lower activity levels than subjects low on Harm Avoidance, whereas subjects high on Reward Dependence had higher overall levels of motor activity than subjects low on Reward Dependence. Older subjects were found to be less active than younger subjects, but the activity level did not differ between males and females.     

Association between morningness-eveningness and mental and physical health in adolescents

Individuals differ in their biological rhythms and their preference for morning or evening hours. Morning types prefer morning hours for intellectual and physical activities while evening types feel and perform best at late afternoon or in the evening. This not only is a simple dichotomous classification but also can be viewed as a continuum. Individual differences in morningness-eveningness are an interesting facet of personality, but little is known about the relationship between psychological factors or health-related variables and morningness-eveningness in adolescents. In Study I, there were positive correlations between morningness and positive attitude towards life and a negative association between morningness and depression. In Study II, there were significant positive relationships between morningness and physical health, mental health, self-esteem, familial relationship, and school functioning. These results indicate that eveningness might be an unspecific risk factor for mental and physical health.     

Association of daytime sleepiness and the morningness/eveningness dimension in young adult subjects in Brazil

Sleepiness is a major public health problem associated with motor vehicle crashes, occupational accidents, decreased productivity, and interpersonal problems. It can be influenced by many factors, including the individual's circadian rhythm. The objective of this study is to assess the correlation between the morningness/eveningness dimension and daytime sleepiness in medical school students. This is a cross-sectional study; 310 subjects (123 women and 187 men, M age 20.5 +/- 1.9 yr.) completed a questionnaire on use of drugs, diagnostic diseases, sleeping habits, the Morningness/Eveningness Questionnaire and the Epworth Sleepiness Scale. The only variable related to daytime sleepiness was the morningness/eveningness dimension (r = -.18, p=.002). Questions with higher coefficients of discrimination between the morning and the evening chronotype were "Lying down to rest in the afternoon when circumstances permit" (.61), "Sitting and reading" (.53), and "As a passenger in a car for an hour without a break" (.53). The implications of the findings are discussed.     

Morningness–Eveningness and Risk Taking

ABSTRACT. Depending on individual differences in biological rhythms and diurnal preferences, people have long been described as either “larks” or “owls.” Larks and owls differ greatly in personality aspects, but from the behavioral perspective it is unclear whether they have significant differences in terms of risky behaviors. Whether morning types or evening types are consistently more risk-taking or risk-averse in different domains remains unknown. This study adopted a general American adult sample to systematically investigate the relationship between chronotype and individuals’ risky behaviors in different domains. By using different methods to measure risky behaviors in different domains, the current research obtained convergent results that morningness was negatively related only to financially risky behaviors for American adults. More specifically, by using the composite scale of morningness and the domain-specific risk attitude scale, Study 1 showed that for American adults, morning types were less likely than evening types to engage in financially risky behaviors (N = 212). In Study 2, after scenario-based methods were used to measure risky behavior, results showed that that participants engaged less in risky behaviors in the domains of gambling and investment (N = 187). A mediator test showed that the negative relationship between morningness and financially risky behaviors was partly mediated by individuals’ self-control ability (self-control scale, Study 1).     

Are Early Birds More Disciplined? A Social Jet Lag Perspective

The relationship between personality and morningness-eveningness orientation is attracting a lot of attention. The relationship between morningness-eveningness orientation and personality related to self-regulation, however, remains unclear. The present research adopted a general American adult sample to investigate the relationship among morning and evening types and the individual self-regulatory trait. More important was that we used social jet lag theory to explain this relationship. According to the different scales that were used to measure self-regulatory trait, Study 1 obtained the convergent result that morningness is positively related to high self-regulation. In Study 2, we found that misalignment of rising time between free and work days (reflecting social jet lag) could partly explain the positive relationship between morningness and self-regulation. More specifically, because morning types can work in accordance with their natural clock, they have more resources for self-regulation; therefore, they have higher-self-regulation than intermediate types and evening types do.     

Age and Sex Differences in Morningness/Eveningness Along the Life Span: A Cross-Sectional Study in Spain

Work psychology has noted the importance of considering the temporal dimension of behavior in organizations. Given that society widely operates on a 24-hr schedule, it is important to know how circadian typologies are distributed in the general population. In this study, diurnal preference was analyzed among 4,175 Spanish participants (61.3% women), 12–59 years old, who completed the Composite Scale of Morningness (Smith, Reilly, & Midkiff, 1989). Several measurement models of the CSM were analyzed using exploratory structural equation modeling and confirmatory factor analysis. The bifactor model showed the best fit, with a general factor (morningness/eveningness) and three subfactors (morningness, morning affect, and time of retiring). The age and sex factorial invariance of the bifactor model were tenable at the latent variance-covariance level. Next, age and sex differences analysis indicated a progressive increase in morningness with age, but over 40 years old, men were more morningness oriented than women were. These results indicate that morningness/eveningness can be considered a multidimensional construct and that psychosocial factors must be considered when estimating the prevalence of morningness/eveningness in different populations or countries.     

The relationships between morningness-eveningness, ageing and personality

In an attempt to study the relationship between ageing and personality and the morningness-eveningness dimension two experiments were carried out. In experiment I, an Italian version of the Morningness-Eveningness Questionnaire (MEQ) was administered to 435 Ss ranging in age from 20 to 79 yr, and divided in to six age groups. In comparison with younger people older S tended to display greater Morningness-Eveningness scores. These results suggest that ageing relates to a shifting toward morningness. In Experiment II the Eysenck Personality Questionnaire (EPQ) and the MEQ were administered to 233 Ss (20–29 yr). Morning-types had significantly higher N scores and tended to be insignificantly more introverted. Evening-types had significantly higher N scores and tended to be insignificantly more extraverted. The present findings are consistent with reports of a tendency for morning-types to be introverted and for evening-types extraverted. However, they do provide some evidence of individual differences on the neuroticism and psychoticism dimensions of personality between the two diurnal types.     

Morningness–Eveningness Scale for Children (MESC): Spanish normative data and factorial invariance according to sex and age

The purpose of the current study was to test the psychometric properties of the Morningness–Eveningness Scale for Children (MESC) to establish normative data, determine cut-off scores for differentiating between morning, intermediate and evening types, and test factorial invariance according to sex and age in a Spanish adolescent population. Additionally, self-reported sleep habits were related to morningness–eveningness (M–E) to study their convergent validity. A sample of 5387 Spanish youth aged 10–16 years old (50% girls) were included in this study. The results revealed that the MESC has acceptable reliability (α = .70), good fit to empirical data with a one-dimensional factorial structure, and metric invariance according to sex and age. M–E scores decreased with age, and boys scored higher in M–E compared to girls. Age and sex size effects were moderate and slight, respectively. The relationship between M–E and sleep habits indicated a delayed pattern of sleep–wake habits in evening types compared to morning types. The Spanish version of the MESC possesses good psychometric properties regarding reliability, metric factorial invariance and convergent validity with self-reported sleep habits.     

Personality correlates of occupational status according to Holland types

The present investigation sought to identify personality correlates of occupational status. Because occupational status is a direct function of occupation, the relationship between personality and status was examined both within and across occupational groups using Holland's 1973 typology. Four two-way analyses of covariance of 16PF (Sixteen Personality Factor Questionnaire, Form A) second-order personality factors were performed using data from 175 employed adult males. No single personality factor was associated with status across occupational types. Among Social occupations, the low-status group had higher Extraversion and lower Anxiety scores than the high-status group. In general, the relationship between personality factors and occupational types provided additional confirmation of Holland's theory using an employed adult sample.     

Circadian preferences and personality traits: A meta‐analysis

In this study we report results of a meta‐analysis of studies linking personality to circadian rhythms. A total of 35 independent samples, 96 correlations and 8589 participants were included. Results showed that conscientiousness is the personality dimension that mostly related to morningness (r = .29). Agreeableness was also related to morningness although to a lesser degree (r = .13). Openness to experience, extraversion and neuroticism, contribute to a very small degree (i.e. ?.09, ?.06 and ?.07, respectively). Furthermore, moderation analyses suggested effects of personality measure (big five vs. other) and sample (students vs. workers). Average age of participants had no significant impact on the relationship between morningness and personality, apart from a very trivial influence on openness to experience. Copyright © 2010 John Wiley & Sons, Ltd.     

To Challenge the Morning Lark and the Night Owl: Using Smartphone Sensing Data to Investigate Day–Night Behaviour Patterns

For decades, day–night patterns in behaviour have been investigated by asking people about their sleep–wake timing, their diurnal activity patterns, and their sleep duration. We demonstrate that the increasing digitalization of lifestyle offers new possibilities for research to investigate day–night patterns and related traits with the help of behavioural data. Using smartphone sensing, we collected in vivo data from 597 participants across several weeks and extracted behavioural day–night pattern indicators. Using this data, we explored three popular research topics. First, we focused on individual differences in day–night patterns by investigating whether ‘morning larks’ and ‘night owls’ manifest in smartphone-sensed behavioural indicators. Second, we examined whether personality traits are related to day–night patterns. Finally, exploring social jetlag, we investigated whether traits and work weekly day–night behaviours influence day–night patterns on weekends. Our findings highlight that behavioural data play an essential role in understanding daily routines and their relations to personality traits. We discuss how psychological research can integrate new behavioural approaches to study personality.     

Morningness versus eveningness arousal patterns in young adults.

The preference for morning versus evening time for activities requiring alertness was investigated. Responses from 9 individuals categorized as "owls" and 7 classed as "larks" based on their scores on the Morningness Versus Eveningness Questionnaire were compared to a group of 11 classified as "neither" on measures of sleep attitude and personality factors of arousal. No statistically significant differences were found; however, an item analysis yielded a statistically significant difference among the groups' responses on questions involving personal choices of sleep/wake schedules. This distinguishing aspect between the groups denotes the utility of subjective measures of preference. Our findings complement those from other subjective and experimental studies of "owls" and "larks" and add the important dimension of inquiring about personal preferences of subjects.     

Happy as a lark: morning-type younger and older adults are higher in positive affect

A literature on young adults reports that morning-type individuals, or "larks," report higher levels of positive affect compared with evening-type individuals, or "owls" (Clark, Watson, & Leeka, 1989; Hasler et al., 2010). Morning types are relatively rare among young adults but frequent among older adults (May & Hasher, 1998; Mecacci et al., 1986), and here we report on the association between chronotype and affect in a large sample of healthy younger and older adults. Overall, older adults reported higher levels of positive affect than younger adults, with both younger and older morning types reporting higher levels of positive affect and subjective health than age mates who scored lower on morningness. Morningness partially mediated the association between age and positive affect, suggesting that greater morningness tendencies among older adults may contribute to their improved well-being relative to younger adults.