Evening adolescents: the role of family relationships and pubertal development.

Accumulating evidence suggests that evening-type adolescents are exposed to a number of determinants that might have a negative impact on their health condition. Despite the fact that biological and psychosocial factors are interrelated, their impacts on the shift toward eveningness during puberty have been considered only separately. In this study, the effects of frequency of conflicts and functional autonomy on the relationship between pubertal development and Morningness-Eveningness (M-E) were tested together. A sample of 2081 adolescents aged 12-16 completed pubertal development, M-E, family frequency of conflicts and functional autonomy scales. Results indicated that greater functional autonomy and more conflicts in the family were unique predictors of greater eveningness, and they both together were better predictors of M-E than an advanced age and pubertal development. Apart from biological development, family relationship seems an important factor explaining progressive tendency toward eveningness during puberty and adolescence. Some implications to adolescent development were indicated.

Hemisphere Preference Test: psychometric properties and relations with academic performance among adolescents.

The present study explored, in adolescents, the dimensionality (factorial structure), reliability (internal consistency and test-retest stability) and predictive validity (in relation with academic grades) of the Hemispheric Preference Test (HPT), a widely used self-report index of thinking styles among adults. A sample of 990 Spanish adolescents aged 10-14 completed HPT and reported their academic grades. Results indicated a two-factor structure for HPT that can be interpreted in terms of left- and right-Hemisphere Preference (HP). The two-factor structure was clearer in boys compared to girls. The internal consistency and test-retest at 6 and 12 months were satisfactory. Left-HP scores decreased with age whereas girls obtained a higher mean score on right-HP sub-scale. Finally, Left-HP accounted for a significant variance percentage on academic grades after controlling for age and sex. Results suggested that Spanish version of the HPT was effective and reliable among adolescents.

Chronotype, Time of Day, and Performance on Intelligence Tests in the School Setting.

Research suggests the existence of an association between chronotype and intellectual performance, but the nature of this link remains unclear. Studies conducted in a laboratory setting point to the synchrony effect (better performance at a person's preferred time of day) for fluid intelligence, but not for crystallized intelligence, whereas studies that have analyzed students' grades suggest that the effect exists for both. In the present study, we aimed to verify the synchrony effect by applying direct measures of crystallized intelligence, fluid intelligence, and subjective sleepiness-alertness in a sample of high school students during their morning or afternoon class. The results revealed a synchrony effect for crystallized, but not for fluid intelligence. During morning class, students with a morning chronotype performed better than evening chronotypes on a test of crystallized intelligence, whereas during afternoon class there was no difference between chronotypes. The association resulted from decreased performance during morning class in evening chronotypes that improved during afternoon class and constant performance in morning chronotypes. These effects were independent of sleepiness-alertness levels. The results suggest that individual differences between chronotypes may be important for tasks performed during morning classes, but not during afternoon ones, and that performance across school days may depend on time of day in evening chronotypes.

Morningness-eveningness and health-related quality of life among adolescents.

Accumulating evidence suggests that evening-type adolescents are exposed to a number of determinants that might have a negative impact on their health condition. Given that few studies have investigated the association between chronotype and quality of life measures in large samples of adolescents, the aim of this study was to assess the relationship between morningness-eveningness and health-related quality of life among 1600 adolescents (aged 12-16 years). Adolescents completed the Veçu et Santé Perçue de L'adolescent (VSP-A) and the Morningness-Eveningness Scale for Children (MESC). Girls and older adolescents reported worse health indicators and were more evening oriented. Evening-type adolescents obtained lower scores on vitality, physical and psychological well-being, body image, relations with parents, relations with teachers, school work and global health scale.

The Parent's Chronotype and Child's Sleeping Quality in Association with Relationship Satisfaction.

The prospective Ulm-SPATZ study was investigated to assess the role of child sleeping quality between 4 to 6 years of age in affecting a partner's sleeping and relationship satisfaction within a couple. The study was conducted using a triadic approach in which the child was included in the Actor-Partner-Interdependence Model (APIM). Sleeping quality of the child was determined by using the German version of the children's sleep habits questionnaire, sleeping features of the parents were assessed by using the Munich chronotype questionnaire, and the partner relationship assessment was performed by employing the German version of the parenting stress index questionnaire. In 211 German triads, we observed that sleeping characteristics and partner relationship scores at different child ages are consistent for both men and women. Higher and statistically significant sleep duration, time spent in bed, the midpoint of sleep, time getting out of bed, and sleep onset in women compared to men during the working days were observed. The APIM analyses showed a significant direct effect of child sleep quality on the partner relationship satisfaction. In women, a mediated effect of child sleep quality acted through sleep duration and time spent in bed on the partner relationship satisfaction score during both free and working days. In men, low child sleep quality was found to be associated with increased sleep onset during both free and working days. Child sleep quality influences relationship satisfaction mostly in mothers, likely because of their higher involvement in childcare during working days. Distress in the couple could be counteracted by a major involvement of the fathers in child management.

[Assortative mating in temperament and intelligence, and the role of marital satisfaction]. / Emparejamiento selectivo en temperamento e inteligencia y su relación con la satisfacción marital.

Assortative mating is the mating of pairs that are more similar in some trait than would be expected from random mating. It takes place when sexually reproducing organisms tend to mate with individuals that are like themselves in some respect (positive assortative mating) or dissimilar (negative assortative mating). The present study measures verbal and nonverbal intelligence, along with several temperamental traits, testing the similarity, complementarity, social homogamy, and convergence hypotheses. The role of marital satisfaction was also analyzed. The sample comprised 357 adults (age range 19-69), who completed verbal aptitude, inductive reasoning, and temperament tests. The findings show that couples are similar in almost all the measured traits, even after controlling for age and educational level. Differences were observed in the couples' degree of similarity depending on the duration of their relationship. Further, only similarity in verbal intelligence for males and in impulsivity for females was associated with marital satisfaction in long-term couples.

Indecision and avoidant procrastination: the role of morningness-eveningness and time perspective in chronic delay lifestyles.

The authors examined how time orientation and morningness-eveningness relate to 2 forms of procrastination: indecision and avoidant forms. Participants were 509 adults (M age = 49.78 years, SD = 6.14) who completed measures of time orientation, morningness-eveningness, decisional procrastination (i.e., indecision), and avoidant procrastination. Results showed that morningness was negatively related to avoidant procrastination but not decisional procrastination. Overall, the results indicated different temporal profiles for indecision and avoidant procrastinations. Avoidant procrastination related to low future time orientation and low morningness, whereas indecision related to both (a) high negative and high positive past orientations and (b) low present-hedonistic and low future time orientations. The authors inferred that distinct forms of procrastination seem different on the basis of dimensions of time.

Morningness-eveningness in adolescents.

Individual morningness-eveningness differences explain the rhythmic variations of behavioral and biological patterns. Several studies have corroborated that morningness preference increases over adulthood and aging. Adolescents shift their time of day preferences from morningness to eveningness during puberty. The aims of this study were translate to Spanish the Morningness-Eveningness Scale for Children (MESC) and to analyze age and sex differences. A group of 600 adolescents (aged between 12 and 16 years) participated in the study. Psychometric analysis showed that reliability and factor structure were suitable and similar to previous studies. The results indicated a clear decrease of morningness as of 12 years. Boys were more morningness-oriented than girls in several items of the questionnaire. In view of the results, several educational implications are raised.

Validity of the Morningness-Eveningness Scale for Children among Spanish adolescents.

Adolescents tend to be much later chronotypes than other age groups. This circadian phase delay is attributed as much to biological as psychosocial factors. Because the consequences of this change on performance and health have been documented, questionnaires to identify morning and evening-type adolescents are necessary. The aim of the present study was to validate a Spanish version of the Morningness-Eveningness Scale for Children (MESC) by means of several relevant psychological variables as external criteria. A sample of 623 urban high school students completed the MESC and self-reported measures of sleep behaviors, subjective alertness, physical performance, and mood. On the whole, results indicate a good validity of MESC. Significant differences in the self-reported ratings between morning and evening types were obtained by time-of-day. These results provide preliminary support for the Spanish version of MESC.

Perceptions of self-concept and self-presentation by procrastinators: further evidence.

Two samples of university students completed self-report measures of chronic procrastination and either self-concept variables (Sample 1, n = 233) or self-presentational styles (Sample 2, n = 210). Results indicated that procrastination was significantly related to a self-concept of oneself as dominated by issues related to task performance, and to self-presentation strategies that reflected a person as continually justifying and excusing task delays and being "needy" of others' approval. It seems that men and women procrastinate in order to improve their social standing by making their accomplishments seem greater than they really are.

[Factorial structure and reliability of Zimbardo Time Perspective Inventory]. / Estructura factorial y fiabilidad del Inventario de Perspectiva Temporal de Zimbardo.

Time orientation is a fundamental psychological variable, what it flows all aspects of human behaviour. Past, present, and future orientation decomposed of allocated into different temporal frames the continual flow of behaviour, providing meaning and coherence. It has been proposed the Zimbardo Time Perspective Inventory (ZTPI) so multidimensional measure of time orientation, which include positive and negative evaluation of past and present, as well as future evaluation. The factorial structure and reliability of ZTPI was analysed on Spanish adult population. The participants were 756 adults with age range 19-67 years old ( M = 40.1, SD = 15.45). The principal components analyses showed five factors, very similar to obtain on nort-american undergraduate samples, even thought a little difference in composition of the present-fatalist factor. The reliability of each factor was suitable. Age and gender differences analysis showed that older groups were more future oriented and less present hedonist, female were high orientation to past negative, past positive and present fatalist, while young females were more future oriented than older females.

Chronotype and time-of-day effects on mood during school day.

Existing evidence suggests an association between mood, time-of-day and morningness-eveningness (M-E). Since few studies have been carried out among adolescents, in this study daily mood fluctuations were analyzed in the naturalistic school context during 2 d in order to test how chronotype and time-of-day are related to mood during the school schedule period and check if sleep length is involved in the above relation. A sample of 655 adolescents (12-16 years) reported mood levels (current level of pleasantness) three times during school day (8:10-8:30 h, 10:20-11:40 h, 13:50-14:10 h). They also reported M-E preference and time in bed. Neither age nor sex were related to mood. However, the results indicated that regardless of chronotype mood increased throughout the school day from the lowest morning levels. Moreover, morning types showed better mood compared to other chronotypes, while evening types exhibited the lowest mood. Evening-oriented students slept less than other chronotypes, but time in bed was not involved in the relationship between chronotype and mood. These results suggest that it is not shortened sleep duration responsible for decreased mood in evening-oriented students.

Composite and preferences Scales of Morningness: reliability and factor invariance in adult and university samples.

The creation and adaptation of scales or inventories assessing specific circadian typologies has been a predominant focus within the field of chronopsychology. The present study addressed the psychometric properties of two scales of morningness-eveningness: the Morningness Composite Scale (CS; Smith, Reilly, & Midkiff, 1989) and the Early/Late Preferences Scale (PS; Smith, Folkard, Schmieder, Parra, Spelten, & Almirall, 1993). Internal consistency and factor invariance of the CS and PS were analyzed in two samples: a group of 203 university students (age range = 19-30) and a group of 125 working adults (age range = 31-65). Results indicated satisfactory internal consistency for both full scales with each age group and confirmed the factor invariance across age for the two CS factors and one of the PS factors. A higher tendency in morningness on both scales was noted in the adult sample.

Daily fluctuations in attention at school considering starting time and chronotype: an exploratory study.

Interest to investigate daily fluctuations in cognitive tasks, so-called "school-rhythms", lies in exploring the most favourable time-of-day for learning considering the analysis of variations in performance taking into account individual differences. The aim of this study was to describe daily fluctuations in attention at three different times of the school day, two different days, considering chronotype and three different school start times (08:00, 08:15 and 08:30 h). Participants were 669 adolescents aged 12-16. Sleep length and inductive reasoning were considered as covariates. In general, attention increased throughout the school day, boys reached higher attention than girls and, moreover, evening type boys reached higher attention than evening type girls. No differences between chronotypes were observed. When students were familiar with the task, chronotype, sex and time-of-day interactions seem to be important factors to consider.

Chronotype, gender, and time for sex.

The study aimed at testing chronotype and gender differences in the time of day when humans feel the greatest need for sex and the time of day they actually undertake sexual activity. A Polish sample of 565 participants aged between 18 and 57 was tested. In females, regardless of chronotype, the greatest need for sex occurred between 18:00 and 24:00, but a secondary peak appeared only in morning types at 6:00-9:00. In males, the greatest need for sex occurred either in the morning or evening hours: in evening types at 9:00-12:00 and 18:00-3:00; in neither types at 6:00-9:00 and 18:00-24:00; in morning types at 6:00-12:00 and 18:00-24:00. Considering time of day when subjects were undertaking sexual activity most frequently, this appeared between 18:00 and 24:00 for all the participants, and prolonged until 3:00 at night in evening type males. Morningness preference was more strongly related to the timing of need for sex than to the timing of actual sexual activity (r = -0.275 vs. r = -0.174), while the timing of desire and the timing of sexual activity were positively, but moderately related (r = 0.320).

Women would like their partners to be more synchronized with them in their sleep-wake rhythm.

Men sleep shorter and go to bed and get up later than women, thus they are later chronotypes. This difference between the sexes is most pronounced between puberty and menopause indicating the possibility that morningness is subject to sexual dimorphism related to reproductive aspects. The objective of the study was to compare the sleep-wake behavior of women with their actual partners and with their preferred partners. As a hypothesis, we expect some assortment in mating concerning chronotype (with the actual partner), but we also expect a higher synchronization with a preferred ideal partner. 167 women were analyzed in this study (mean age: 23.0 ± 2.57 (SD) years). Mated women were earlier chronotypes than their partners (t = -2.051, p = .042, d = .34) but the difference was small (11:02 min ± 1:04 min). The results of the present study showed women preferring a partner synchronized to their own sleep-wake-rhythm more than their actual partners were. The above result was true either for single facets of the sleep-wake rhythm (e.g. bed time, sleep onset) or for midpoint of sleep on free days - an indicator of actual chronotype: women's and their partners' correlation of midpoint of sleep was lower (r = .513) than women's and their ideal partners' correlation (r = .855). Amongst various sleep-wake measures, women particularly preferred a partner going to bed at the same time. Assortative mating according to sleep-wake rhythm exists, but women for long-term pair-bonds would like their partners far more synchronized.

Circadian preference and thinking styles: implications for school achievement.

Research has shown that thinking styles could have an influence on academic achievement. Previous studies have described that evening types are usually right-thinkers who tend to be creative and intuitive, whereas morning types tend to be left-thinkers who prefer verbal and analytic strategies in processing information. However, these studies have been realized among undergraduates, who have more freedom to choose their time schedules according to their circadian preference than adolescents or adult workers. On other hand, the relationship between thinking styles and circadian preference has not been analyzed considering school achievement. The present study aims (1) to investigate the relationship between circadian preference, that is, behavioral differences in circadian rhythmic expression, and thinking styles, referring to the preference toward information processing typical of the right versus the left cerebral hemisphere; and (2) to test the implications for self-reported school achievement. A sample of 1134 preadolescents and adolescents (581 girls; mean ± SD age: 12.1 ± 1.47, range: 10-14 yrs) completed the Morningness-Eveningness Scale for Children (MESC) as measure of circadian preference (morning, neither, or evening types), the Hemispheric Preference Test (HPT), conceived as a tool to measure thinking styles (right-, balanced-, and left-thinkers), and self-reported school achievement. Results indicated a greater percentage of left-thinkers among morning types and a greater percentage of right-thinkers among evening types. No differences were found among balanced-thinkers and neither types. Morning types and left-thinkers reported the highest subjective level of achievement, followed by evening types and left-thinkers, and morning types and right-thinkers. Evening types and right-thinkers reported the lowest subjective level of achievement. Finally, multivariate regression analysis indicated that age, left hemisphere and morning preferences accounted for 14.2% of total variance on self-reported achievement.

Morningness and life satisfaction: further evidence from Spain.

Life satisfaction is a crucial component of well being, thus research of its determinants are of great importance and are conducted worldwide. Recently, morningness has been shown to be related to greater life satisfaction in Polish and German samples; and in the present study, this relationship was tested in a Spanish adult sample. The results provide further evidence for the relationship of morningness with higher life satisfaction, which it seems independent of culture and geographic location.

Morningness-eveningness and sleep habits among adolescents: age and gender differences.

Previous research has indicated the need to use large samples in different cultural contexts in order to clarify age and gender differences on morningness-eveningness and sleep habits. The goal of our research was to study the relationship between morningness-eveningness and sleep habits in a large sample of 2,649 adolescents between 12 and 16 years. The Morningness- Eveningness Scale for Children and an adaptation of the School Sleep Habits Survey measures were used. Results indicated a greater tendency toward eveningness with age and higher eveningness in 13- and 14-year-old girls. Older adolescents claimed later rising time on weekends, later bedtime and shorter sleep length, and greater social jetlag, weekend rise time delay, and weekend bedtime delay. Girls reported earlier rising time on weekdays, later rising time on weekends, longer sleep length on weekends, and greater social jetlag and weekend rising time delay. Lastly, evening oriented adolescents claimed later rising time and bedtime, shorter sleep length on weekdays but longer sleep duration on weekends, and greater social jetlag, weekend rising time delay, and weekend bedtime delay.