Morningness-eveningness Preferences Research Articles

The Interplay of Time-of-day and Chronotype Results in No General and Robust Cognitive Boost

Using physiologically validated questionnaires in which the peak of circadian arousal is determined through morningness-eveningness preferences, individuals can be categorized into morning or evening chronotypes. Typically, individuals with such chronotypes are assumed to show better cognitive performance at their subjective peak of circadian arousal than at off peak. Although this so-called synchrony effect is accepted as common knowledge, empirical evidence is rather mixed. This may be explained by two methodical challenges. First, most studies are underpowered. Second, they include one task, but tasks differ across studies. Here, we tested the synchrony effect by focusing on two cognitive constructs that are assumed to underlie a wide variety of behaviors, that is: short-term maintenance and attentional control. Short-term maintenance refers to our ability to maintain information temporarily. Attentional control refers to our ability to avoid being distracted by irrelevant information. We addressed the methodical challenges by asking 446 young adults to perform eight tasks at on- and off-peak times. Four tasks were used to assess temporary maintenance of information (i.e., short-term memory). Four tasks were used to assess temporary maintenance and manipulation of information (i.e., working memory). Using structural equation modeling, we modeled attentional control as the goal-directed nature of the working-memory tasks without their maintenance aspects. At the individual-task level, there was some evidence for a synchrony effect. However, the evidence was weak and limited to two tasks. Moreover, at the latent-variable level, the results showed no evidence for a robust and general synchrony effect. These results were observed for the full sample (N = 446) and the subsample including participants with moderate to definite morning or evening chronotypes (N = 191). We conclude that the synchrony effect is most likely a methodical artefact and discuss the impact of our research on psychological science and scientific research more widely.

Distribution of dim light melatonin offset (DLMOff) and phase relationship to waketime in healthy adults and associations with chronotype

ObjectivesDim light melatonin onset, or the rise in melatonin levels representing the beginning of the biological night, is the gold standard indicator of circadian phase. Considerably less is known about dim light melatonin offset, or the decrease in melatonin to low daytime levels representing the end of the biological night. In the context of insufficient sleep, morning circadian misalignment, or energy intake after waketime but before dim light melatonin offset, is linked to impaired insulin sensitivity, suggesting the need to characterize dim light melatonin offset and identify risk for morning circadian misalignment. MethodsWe examined the distributions of dim light melatonin offset clock hour and the phase relationship between dim light melatonin offset and waketime, and associations between dim light melatonin offset, phase relationship, and chronotype in healthy adults (N = 62) who completed baseline protocols measuring components of the circadian melatonin rhythm and chronotype. Results74.4% demonstrated dim light melatonin offset after waketime, indicating most healthy adults wake up before the end of biological night. Later chronotype (morningness-eveningness, mid-sleep on free days corrected, and average mid-sleep) was associated with later dim light melatonin offset clock hour. Later chronotype was also associated with a larger, positive phase relationship between dim light melatonin offset and waketime, except for morningness-eveningness. ConclusionsThese findings suggest morning circadian misalignment risk among healthy adults, which would not be detected if only dim light melatonin onset were assessed. Chronotype measured by sleep timing may better predict this risk in healthy adults keeping a consistent sleep schedule than morningness-eveningness preferences. Additional research is needed to develop circadian biomarkers to predict dim light melatonin offset and evaluate appropriate dim light melatonin offset timing to promote health.

Morningness-eveningness Preferences among Medical Students: A Cross-sectional Study

Introduction: Morningness and eveningness is a phenomenon which looks at the differences among the individuals regarding their diurnal preferences, sleep-wake pattern of activity and alertness in evening or morning. Morning chronotypes are individuals who exhibit morning tendencies like rising early in the morning while evening chronotypes prefer to get up later in the morning and stay awake later at night time and also perform their best during late afternoon or evening. Morning chronotypes are known to exhibit better physical and mental health, greater self-esteem and academic performance. Aim: To estimate the prevalence of morningness and eveningness among medical students. Association of chronotype with academic performance was also determined. Materials and Methods: The present cross-sectional study was conducted on 110 apparently healthy medical students at Shaheed Hasan Khan Mewati Government Medical College, Nalhar, Haryana, India from October 2021 to January 2022. All the participants were sent a validated Morningness-Eveningness self-assessment Questionnaire (MEQ). Data of chronotypic preferences expressed as frequencies of participants (%) and association determined using Pearson’s Chi-square test and p-value <0.05 was considered statistically significant. Results: Study revealed that 67 (61%) students belonged to the Intermediate (I) chronotype, around one-fourth {n=26 (24%)} were Morning (M) type while 17 (15%) were Evening (E) type. Morningness was more frequently reported by females as compared to males in n=8 (28%) vs. n=18 (22%) respectively. Higher scores (≥50%) were more prevalent among M types as compared E types in n=10 (38%) vs. n=3 (18%) respectively}; however, association between chronotype and academic performance could not reach significant level (p-value=0.15). Conclusion: The distribution of chronotypes in study sample provided the evidence that majority of students could be classified as intermediate type. Morningness was more frequent in females as compared to males. Further studies with large sample size are needed to explore the influence of chronotype on academic performance.

Burnout and engagement in university students: relationships with morningness-eveningness preferences, average sleep length and social jetlag

ABSTRACT Academic burnout and engagement are critical factors in student success, school attendance and dropout. It is important to determine the variables associated with burnout and engagement to develop university students and their competencies. Therefore, the current study aims to elucidate the association of morningness-eveningness preferences, average sleep length (ASL) and social jetlag (SJL) with burnout and engagement in university students. The sample was composed of 270 university students. The composite scale of morningness (CSM), the Maslach burnout inventory-student scale, student engagement scale and a questionnaire were utilized. CSM total score was found to correlate with both burnout and engagement sub-domains significantly. In addition, CSM total score was a significant predictor in all burnout and engagement models. ASL was a significant predictor of exhaustion and cynicism while SJL was significant predictor of efficacy. Both ASL and SJL were significant predictors of silent in-class behaviours sub-domain of engagement. In sum, CSM total score was found to be the most significant predictor of both burnout and engagement compared to other study variables. Considering the relationships of CSM total score with burnout and engagement sub-dimensions, eveningness can be treated as an important risk factor for burnout and engagement in the context of university students.

Chronotype and Life Satisfaction: The Role of Sex and Age

Chronotype represents the preference for evening or morning hours for mental and physical performance and viewed as a stable human behavioral trait and personality feature. Chronotype relates to many biological, social, and psychological aspects. Depression, anxiety, and health problems are associated with eveningness in the clinical and non-clinical populations. At the same time, morningness demonstrates a positive relationship with well-being (Randler, 2008a). Many studies show that age and sex is a significant predictor of time-of-day preference (Adan et al., 2012). This study is attempted to investigate the association between life-satisfaction and morningness-eveningness and explore age and sex differences. Two hundred thirty-eight persons participated in this study; age distribution was: 17–28 years. The reduced Morningness–Eveningness Questionnaire was used to measure chronotype preferences, and Social frustration and life satisfaction scale were used to assess the subjective level of life satisfaction. Age differences were found for chronotype demonstrating the tendency to eveningness for young adults (23–28 age) than for students (18–22 age), but no sex differences in morningness-eveningness were found. Eveningness negatively correlates with all life-satisfaction dimensions, but this association differs depending on sex and age. In general, the morningness-eveningness preferences seem to be dependent on age more than sex, but the life satisfaction influenced by both factors. We may report the existence of association between eveningness and life satisfaction, which is much more reliable for men and younger persons.

Does visual search mediate the effect of chronotype on driving behaviour: Evidence from simulated driving

Chronotype refers to individual differences in the timing of circadian sleep-wake cycles and subjective alertness throughout the day. It is a potential factor influencing people's driving behaviour, but no research has explored the mechanisms underlying this topic. The current study aimed to explore the relationship between morningness-eveningness preferences and driving behaviour and the mediating effect of visual search between them. Thirty-eight drivers were selected to participate in this study based on their chronotype. They were divided into morning-type and evening-type groups by their score on the reduced Morningness-Eveningness Questionnaire (rMEQ). Both groups completed a visual search task and a simulated driving task in a morning session and an evening session. The results showed that morningness-eveningness preferences had synchronous effects on basic driving performance; specifically, morning-type drivers showed better driving behaviour in the morning than in the evening, and evening-type drivers showed the opposite trend. Furthermore, visual search abilities showed a mediating effect between morningness-eveningness preference and driving performance. The mechanisms underlying these results are discussed. Related results and data could aid with schedule arrangements for professional drivers.

Association between morningness‐eveningness, sleep duration, weekend catch‐up sleep and depression among Korean high‐school students

The present study aimed to examine the association between morningness-eveningness preferences, sleep duration, weekend catch-up sleep duration and depression among Korean high-school students. A total of 8,655 high-school students participated from 15 districts in South Korea and completed an online self-report questionnaire. The following sleep characteristics were assessed: weekday and weekend sleep duration, weekend catch-up sleep duration, morningness-eveningness preference, perceived sufficiency of sleep, self-reported snoring and sleep apnea, daytime sleepiness, and sleep environment. Age, gender, body mass index, number of private classes, proneness to internet addiction, and depressive mood were also evaluated. A logistic regression analysis was conducted to compute odds ratios for the association between depression and sleep characteristics, after controlling for relevant covariates. Eveningness preference was a significant predictor of depressive mood (adjusted OR, 1.71; 95% CI, 1.47-1.99). Weekend CUS durations that were ≥2hr and enrollment in numerous private classes were associated with a lower risk for depression (0.68, 0.55-0.85; 0.76, 0.60-0.95; respectively). Female gender, underweight and obese body weight, short weekday sleep durations, excessive daytime sleepiness, perceived excessiveness and insufficiency of sleep, self-reported snoring and sleep apnea, proneness to internet addiction and a non-optimal sleep environment were associated with an increased risk for depression. Eveningness preference and insufficient weekday sleep duration were associated with an increased risk for depression. Weekend CUS duration ≥2hr reduced the risk for depression. Diverse aspects, including sleeping habits and sleep-related environmental factors, should be considered to reduce depressive symptoms in late adolescents.

Circadian preferences of birdwatchers in Poland: do "owls" prefer watching night birds, and "larks" prefer daytime ones?

Birdwatching is a very popular and increasing leisure activity, and the study and observation of birds is more popular in the morning due to the greater activity among birds at that time of day. The aim of our study was to find out whether there was a relationship between the circadian preference of observers and their favourite bird species and whether it was influenced by such factors as professional status, age and gender. In an e-mail survey we asked a total of 433 Polish ornithologists (professionals) or birdwatchers (non-professionals) for their morningness–eveningness preferences (four categories) and favourite (open choice) bird species and received 143 responses. The temporal (circadian) preferences of respondents declined from early morning (35.7%) to evening/nighttime (11.4%). Circadian preference categories differed significantly by age, with early morning respondents significantly older. These preference categories did not differ significantly in terms of response time to the survey invitation or in the percentage of their favourite birds that were categorised as daytime birds. A total of 204 species were identified as favourite birds of which 34 species were mentioned by five or more respondents, with only two, the common crane Grus grus and the Eurasian pygmy owl Glaucidium passerinum mentioned by more than 10% of respondents. The white stork Ciconia ciconia was more popular with professionals than non-professionals and the swift Apus apus less popular. A significant gender × circadian preference interaction was detected for the percentage of favourite birds categorised as daytime birds, with fewer daytime birds among early morning female recorders. The presented results are obviously of a correlative nature, but open the door for further, more advanced study and suggest there may be a need to investigate temporal biases when analysing citizen-based data.

Factorial Structure of the Morningness-Eveningness-Stability-Scale (MESSi) and Sex and Age Invariance.

Assessing morningness-eveningness preferences (chronotype), an individual characteristic that is mirrored in daily mental and physiological fluctuations, is crucial given their overarching influence in a variety of domains. The current work aimed to investigate the best factor structure of an instrument recently presented to asses this characteristic: the Morningness-Eveningness-Stability-Scale improved (MESSi). For the first time, the originally proposed three-factor structure was pitched against a uni- and a two-factor solution. Another novelty was to establish that the best-fitting model would be invariant in relation to sex and age, two variables that influence chronotype. A Confirmatory Factor Analyses on the data obtained from a sample of 2096 German adults (age: 18–76; M = 25.5, SD = 7.64) revealed that the originally proposed three-factor structure of the MESSi – Morning Affect, Eveningness, and Distinctness – was the only one to achieve acceptable fit indicators. Furthermore, each scale obtained good internal consistency. In order to assess age invariance, following the literature on development and chronotype, our sample was divided into three age groups: 18–21 years, 22–31 years, and 32 years or older. Full measurement invariance of the three-factor model was found for sex and age. Regarding differences between sexes, females did not differ significantly from males in Morning Affect, but scored significantly lower on Eveningness and higher on Distinctness; this last result has been consistent across validation studies of the MESSi. With respect to age differences, the oldest group scored lower on Eveningness and Distinctness in comparison with the other two age-groups; the intermediate group (age: 22–31) scored lower on Morning Affect when compared to both the younger and older age groups. Additionally, both Eveningness and Distinctness were negatively correlated with age. This latter relation has been consistently reported in other validation studies. Our results reinforce the idea that the MESSi assesses three different components of chronotype in a reliable manner and that this instrument can be used to explore sex and age differences.

Salivary Pubertal Hormones, Sleep Disturbance, and an Evening Circadian Preference in Adolescents: Risk Across Health Domains

PurposePuberty influences biological and psychological development during adolescence. This includes a shift toward an evening circadian preference, which is characterized by greater physical and mental activity at night compared to the morning. This study examines how pubertal hormones are related to risk across key health domains among adolescents with an evening circadian preference. MethodsParticipants were adolescents with an evening circadian preference (n = 165, 96 female and 69 male, mean age = 14.8) from an NICHD-funded study. Hormones included testosterone, dehydroepiandrosterone (DHEA), and estradiol (females only). Sleep measures included weeknight total sleep time and weeknight bedtime. Circadian preference was assessed with the Children's Morningness-Eveningness Preferences Scale. Health domains included emotional, cognitive, behavioral, social, and physical health. ResultsFor female adolescents, estradiol was related to higher risk in the emotional domain. Among female adolescents with later bedtimes, higher estradiol was associated with higher behavioral domain risk (specifically alcohol and substance use). For male adolescents with a more extreme evening circadian preference, higher DHEA and testosterone were associated with higher behavioral domain risk, specifically greater alcohol and substance use or sensation seeking (DHEA only). Among female adolescents with a more extreme evening circadian preference, higher DHEA was associated with greater physical health risk. ConclusionsPubertal hormones may be associated with heightened risk across select health domains. Specifically, higher levels of hormones may contribute to increased risk for alcohol and substance use as well as sensation seeking in the context of an evening circadian preference.

Effects of time of day on age-related associative deficits.

Time of day is known to influence cognition differently across age groups, with young adults performing better later than earlier in the day and older adults showing the opposite pattern. Thus age-related deficits can be smaller when testing occurs in the morning compared with the afternoon/evening, particularly for tasks requiring executive/controlled/inhibitory processes. Stronger influences of time of day were therefore predicted on associative than on item recognition memory based on their differential requirements for demanding recollective (rather than familiarity) processes. In 2 experiments, participants were presented with unrelated word pairs and then tested on both item recognition (old/new item?) and associative recognition (intact/recombined pair?). In Experiment 1, young adults were tested either in the morning or in the evening; recognition memory was better when time of testing matched participants' morningness-eveningness preferences, and more so for associative than for item memory. In Experiment 2, young and older adults (evening and morning types, respectively) were tested both in the morning and in the evening; again, recognition memory was better at participants' preferred times of day, especially for associative memory. Consequently, age-related associative deficits varied considerably-indeed more than fourfold-from a nonsignificant 8% for testing in the morning to a substantial 35% for testing in the evening, suggesting that it is important to consider time of day effects in future studies of the associative deficit hypothesis. (PsycINFO Database Record

Sleep, Circadian Rhythms, and Risk Across Health Domains in Adolescents With an Evening Circadian Preference

Sleep and circadian rhythm changes during adolescence contribute to increased risk across emotional, behavioral, cognitive, social, and physical health domains. This study examines if sleep and dim light melatonin onset (DLMO) are related to greater risk in these 5 health domains. Participants were 163 (93 female, age = 14.7 years) adolescents with an evening circadian preference from a study funded by the Eunice Kennedy Shriver National Institute of Child Health and Human Development. Sleep and circadian measures included weekday total sleep time (TST), bedtime, and shut-eye time assessed via sleep diary, the Children’s Morningness–Eveningness Preferences scale, and DLMO. Health domains included self-reported emotional, cognitive, behavioral, social, and physical health. Later DLMO was significantly associated with shorter weekday TST, later weekday bedtime, and later weekday shut-eye time, as well as lower risk in the behavioral domain. At the trend level, later DLMO was related to fewer physical health problems. Earlier DLMO combined with a later bedtime, later shut-eye time, or shorter TST predicted greater risk in the cognitive domain. Later DLMO and shorter TST or a later bedtime predicted worse physical health. DLMO timing was not related to the emotional or social domain. There is evidence that a discrepancy between sleep behaviors and the endogenous circadian rhythm may be related to risk in the cognitive domain for adolescents with an evening circadian preference. Preliminary evidence also indicated that a delayed DLMO and shorter TST or a later bedtime may be related to vulnerability to physical health risk.

Morningness-Eveningness preferences and academic results: correlation between practical and theoretic discipline

Human beings organize most of their biological and behavioural activities according to a 24h period. The biological rhythms show differences between individuals and this variability is known as Circadian Typology (CT). Morning-types (M-types), are active early in the morning and soon reach their peak in mental and physical performance but tire early in the evening. Evening-types (E-types) find difficult to get up in the morning and require more time to reach their optimal status. Neither-types (N-types) show intermediate characteristics. Many studies indicate that age and sex may influence: morningness preference increases with age in adults, and women show a stronger trend toward morningness than men [1]. Student chronotype can represent one of the factors that may affect academic achievement. This study investigates whether the CT of the students is related to the final exam grades of two different disciplines, theoretic (Anatomy) and practical (Athletics). Anatomy and Athletics grades are good indicators of the overall academic performance of the undergraduates. The aim of this study was to evaluate whether the performance in Anatomy is correlated with Athletics for the three chronotypes. Participants were recruited among students of the School of Sport Science, University of Milan. They were 427 (294 males; 133 females). They completed the Morningness-Eveningness Questionnaire (MEQ): 44 students were classified as M-types, 280 as N-types and 103 as E-types. Individual performance in the final exams of Anatomy and Athletic were collected among them. M-type students achieved better results on final exams in Anatomy and Athletic than either E-type or N-type students. Moreover for M-types (R2= 0.187), it was observed a higher correlation concerning the results of the two disciplines than E-types (R2=0.0727) and N-types (R2=0.0236).

Ontogeny of morningness-eveningness across the adult human lifespan.

Sleep timing of humans can be classified alongside a continuum from early to late sleepers, with some people (larks) having an early activity, early bed, and rise times and others (owls) with a more nocturnally orientated activity. Only a few studies reported that morningness-eveningness changes significantly during the adult lifespan based on community samples. Here, I applied a different methodological approach to seek for evidence for the age-related changes in morningness-eveningness preferences by using a meta-data from all available studies. The new aspect of this cross-sectional approach is that only a few studies themselves address the age-related changes of the adult lifespan development, but that many studies are available that provide exactly the data needed. The studies came from 27 countries and included 36,939 participants. Age was highly significantly correlated with scores on the Composite Scale of Morningness (r = 0.70). This relationship seems linear, because a linear regression explained nearly the same amount of variance compared to other models such as logarithmic, quadratic, or cubic models. The standard deviation of age correlated with the standard deviation of CSM scores (r = 0.55), suggesting when there is much variance in age in a study; in turn, there is much variance in morningness. This meta-analytical approach shows that morningness-eveningness changes across the adult lifespan and that older age is related to higher morningness.

Morningness–eveningness preferences in Portuguese adolescents: Adaptation and psychometric validity of the H&O questionnaire

Throughout development individuals vary in their circadian preferences. One of the most notable changes occurs during adolescence when individuals tend to become progressively more evening-oriented. This is a critical age period to be studied given that eveningness preferences seem to relate with physical, psychological and social problems, whereas the most morning-oriented individuals tend to be protected against these problems. The aim of this study was to adapt and present the psychometric validity of the Morningness–Eveningness Questionnaire (Horne & Östberg, 1976) to Portuguese adolescents (12–14years old). To this end, 300 adolescents responded to the questionnaire which was initially translated, re-translated, and then subject to a think-aloud procedure. Overall, the psychometric measures were positive. We found no significant effect of sex on the circadian preferences and a tendency for increased eveningness as age progresses, especially in males. We discuss our results in light of the existing literature.

Chronotypes in an Uruguayan population affected by multiple sclerosis

Sleep disturbances in Multiple Sclerosis (MS) are common. Disturbances of the sleep–wake cycle have social, working and even therapeutic implications (i.e. regarding the timing at which treatments are delivered). The aim of our study was to evaluate the morningness–eveningness preferences in a group of MS affected patients and compare this results with the chronotypes of a control group free from neurological diseases. Fifteen patients from the outpatients MS clinic were included, 12 women and 3 men, with median age 47 [32–67] years. The control group included 8 individuals, 6 women and 2 men, with median age 46 [30–56] years. Both groups were paired by age and sex. A validated Spanish translation of the Horne-Ostberg Morningness–Eveningness Questionnaire (MEQ) was used to study chronotypes. Percentages between groups were compared by the Fisher Exact test and scores by the Mann–Whitney test. In the studied population, MEQ test total score showed a median of 56 points in controls [50–66], belonging to the neither chronotype, and a median of 64 in patients [36–75], classified as moderately morning chronotype. Individualized classifications analysis showed: 1.Patients: a. Definitely Evening Chronotype (EEC): 0 patient (0%); b. Moderately Evening Chronotype (MEC): 2 patients (13%); c. Neither Chronotype (IC): 3 patients (20%); d. Moderately Morning Chronotype (MMC): 5 patients (33%); e. Definitely Morning Chronotype (EMC): 5 patients (34%). 2.Controls: a. DEC: 0 (0%); b. MEC: 0 (0%); c. N:7 (88%); d. MMC: 1 (12%); e. DMC: 0 (0%). MMC and DMC were more frequently observed in MS patients (67 % vs. 12 % in controls; ( p = 0.019). Controls showed higher proportion of NC ( 88% vs. 20% in MS patients; p = 0,003). (1) Chronotypes in the analyzed MS population tend to be morning types. (2)They differ from control population, which presents a non preferential (neither) circadian trend. (3) There appears also a tendency in MS towards a moderately evening preference, although not statistically significant, probably due to the small number of cases and controls studied. (4) Differences should be confirmed studying a larger population. Hospital de Clínicas - Instituto de Neurología.

Sleep Problems, Chronotype, and Diurnal Preferences in Children and Adults with Spina Bifida

Spina bifida meningomyelocele (SBM) is a neural tube defect that involves dysraphism of the spinal cord and extensive reorganization of the brain. The authors assessed the relationship between chronotype, diurnal preferences, and sleep problems in individuals with SBM and healthy controls. Although individuals with SBM showed the characteristic decelerating quadratic relationship between age and chronotype, the curve was displaced, peaking at a younger age in controls compared with SBM (23.4 vs. 29.2 years). Groups did not differ in morningness-eveningness preferences. Individuals with SBM endorsed more sleep problems than controls. Further examination of the relationship between entrainment and sleep in SBM is warranted.

Double trouble? The effects of sleep deprivation and chronotype on adolescent affect

Two understudied risk factors that have been linked to emotional difficulties in adolescence are chronotype and sleep deprivation. This study extended past research by using an experimental design to investigate the role of sleep deprivation and chronotype on emotion in adolescents. It was hypothesized that sleep deprivation and an evening chronotype would be associated with decreased positive affect (PA), increased negative affect (NA), and lower positivity ratios. Forty-seven healthy adolescents (aged 10-15 for girls, 11-16 for boys) participated in a sleep deprivation and a rested condition. A subsample of 24 adolescents was selected on the basis of extreme morningness or eveningness scores (based on outer quartiles of scores on the Children's Morningness-Eveningness Preferences Scale). PA and NA were measured using the Positive and Negative Affect Schedule for Children, and positivity ratios were calculated by dividing PA by NA. Participants reported less positive affect and lower positivity ratios when sleep deprived, relative to when rested. Evening chronotypes reported less positive affect and lower positivity ratios than morning chronotypes in both rested and sleep deprivation conditions. These findings extend previous research by suggesting that adolescents are adversely impacted by sleep deprivation, and that an evening chronotype might serve as a useful marker of emotional vulnerability. Early intervention and prevention strategies can focus on improving sleep and on using chronotherapy principles to reduce eveningness.

Morningness-Eveningness Preferences and Academic Achievement of University Students

The present study investigates whether the circadian preferences of students are related to their academic achievements. This study explores whether different class times affect students' achievement and examines the performance of students on final exams administered at 09:30 h for differences according to chronotype. A total of 1471 university students between 18 and 25 yrs of age responded to a morningness-eveningness questionnaire (MEQ), and data on their cumulative grade point averages (CGPA) were also collected from their transcripts. Some of the students in the sample attended classes during the first teaching period, which started at 08:00 h and ended at 14:50 h, and the remaining students followed the second schedule, which started at 15:00 h and ended at 21:50 h. MEQ scores were found to differ by sex. MEQ scores partially predicted academic success and that students' academic achievements differed according to the time of the teaching period. Moreover, final exam (administered at 09:30 h) scores differed with respect to their circadian preferences; students with a morning preference achieved higher scores than either those with an evening or intermediate preference. Both teaching and test start times thus impact academic performance. (Author correspondence: sbesoluk@sakarya.edu.tr)

Morningness–eveningness preferences and university entrance examination scores of high school students

This study explored whether morningness–eveningness preference influences achievement in a standardised university entrance examination. A total of 235 senior high school students aged 17–19 years responded to the Morningness–Eveningness Questionnaire (MEQ). The obtained MEQ responses indicated that out of 235 participants, 19.1% were “moderately morning” type, 68.1% were “neither” type, 11.9% were “moderately evening” type and 0.9% were “definitely evening” type (there was no “definitely morning” type student in the sample). A significant correlation was observed between MEQ scores and university entrance examination scores. In addition, morningness–eveningness preference was found to effect success in a university entrance examination. “Morning” type students performed better compared to “neither” type and “evening” type students, indicating that students with “morning” type circadian preference are at an advantage because of the starting time of the university entrance examination.