Publications by authors named "Juan F Diaz-Morales"

The aim of the present study was to conduct a preliminary study of the Stanford Gender-Related Variables for Health Research (GVHR) adapted to the Spanish population, testing its factor structure, sex factorial invariance and relationship with health variables. Participants were 438 adults between 19-73 years old ( = 31.90, = 12.

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Morningness-eveningness reflects individual differences in circadian functioning and is related to health and well-being. Cross-cultural comparison could facilitate understanding of the environmental factors affecting morningness-eveningness, which requires establishing cross-cultural validity of the relevant assessment tools. In this study, we applied the Composite Scale of Morningness (CSM) to Bangladeshi ( = 1015; 37.

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The main objective of this study was to explore the differences in sleep habits and chronotype across different age groups in Mexican adolescents attending a permanent double-shift school system. This cross-sectional study consisted of 1,969 (1,084 girls) students from public elementary, secondary, and high schools, as well as undergraduate university students from Mexico. Age range was 10-22 [15.

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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 (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.

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Biological and psychosocial factors have been related to the shift to eveningness during early adolescence but it is necessary to study them from a longitudinal perspective. This longitudinal study examined the contribution of these factors to the onset of a shift towards eveningness in early adolescence. A sample of 440 (49.

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The aim of the present study was to adapt the Morningness-Eveningness-Stability Scale improved (MESSi) to the Spanish adolescent population, testing its factor structure and construct validity. The participants were 725 adolescents (52.9% girls; = 14.

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On the Morningness/Eveningness (M/E) continuum, eveningness has been related to mood disorder and poor well-being. M/E differs between men and women throughout their lifespan. However, there is a lack of information on sex differences in the relationship between M/E, mood, and well-being.

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Objective: To determine the differences between sleep habits and circadian preference in school-aged children attending a Mexican double-shift school system.

Methods: This cross-sectional study consisted of 400 elementary public-school children (mean age = 10.77, SD = 0.

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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.

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This study aimed to validate the Morningness-Eveningness-Stability-Scale improved (MESSi) in Mexico, analyzing the factor structure and sleep habits, combined with the proposal of cutoff values for the scales, and to assess the relationship with substance use. We applied the questionnaires through an online survey to a total sample of 510 Mexicans, aged 18-77 years (M = 27.79, SD = 10.

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Mate selection is part of a growing interest in the study of processes by which couples are established, consolidated and/or separated. Similarity in psychological traits has been related to the well-being of couples, but given the possible effect of temporal convergence, it is necessary to control for the relationship length and whether or not both members of the couple live together. The aim of this study was to analyse the association between Morningness/Eveningness (M/E) similarity and relationship satisfaction in young-dating-non-cohabiting, young-married-cohabiting and old-married-cohabiting couples.

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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.

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Background: The effect of morningness-eveningness, sleep habits, and intelligence on academic performance has been studied in a fixed morning school shift. However, no studies have analysed these variables in an afternoon school shift and tested whether morningness-eveningness is related to academic performance beyond sleep habits and intelligence effects.

Aims: The psychometric properties of the Morningness-Eveningness Scale for Children (MESC) were analysed.

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The aim of this study was to provide validity for the Spanish version of the Morningness-Eveningness-Stability Scale - improved (MESSi), a novel evolved assessment of circadian typology which considers the subjective phase and amplitude by morning affect (MA), eveningness (EV) and distinctness (DI; subjective amplitude) sub-scales. Convergence validity of the MESSi with the reduced Morningness-Eveningness Questionnaire (rMEQ) and relationships with the General Health Questionnaire (GHQ-12) and sensitivity to reward and punishment (SR and SP) were analyzed. Two different Spanish samples, young undergraduate students (n = 891, 18-30 years) and adult workers (n = 577, 31-65 years) participated in this study.

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The aim of the present study was to conduct the preliminary adaptation of the Morningness-Eveningness-Stability-Scale improved (MESSi) to Spanish population, testing its factor structure and construct validity. Participants were 261 adults (65% women; M = 31.4, SD = 12.

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At the onset of puberty, students shift their sleep to later hours, but school starts early. It is suggested that evening orientation and early school start times do not go well together. Therefore, the aim of this study was to investigate sleep problems in adolescence, and it was expected that the adolescents' eveningness orientation is associated with many sleep-related problems.

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Morningness-Eveningness Stability Scale improved (MESSi) is a newly constructed measure to assess circadian types and amplitude. In this study, we applied this measure to participants from three different countries: Germany, Spain and Iran. Confirmatory factorial analysis (CFA) of MESSi displayed mediocre fit in the three countries.

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Measuring morningness-eveningness is an important aspect of individual differences because it is associated with many aspects of personality and health. The present study outlines recent advancements in the field of measurement and proposes an improved assessment of morningness-eveningness, such as the measurement of circadian amplitude, updating and reflecting new item developments, addressing the clock time based measures, the morning-biased items and the aspect of uni versus multidimensionality. Four studies have been carried out in Germany to present a novel development (with a total sample of N = 1181).

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Facebook has become the most popular social networking site round the world. In seeking an explanation for this phenomenon, individual differences in circadian functioning seem to be an interesting issue. The main aim of this study was to examine the potential associations between morningness/eveningness and Facebook use (intrusion and intensity).

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Adolescents in high school suffer from circadian misalignment, undersleeping on weekdays and oversleeping on weekends. Since high schools usually impose early schedules, adolescents suffer from permanent social jetlag (SJL) and thus are a suitable population to study the effects of SJL on both academic and cognitive performance. In this study, 796 adolescents aged 12-16 years reported information about their sleep habits, morningness-eveningness (M-E), cognitive abilities and grade point average (GPA).

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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).

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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.

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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.

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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.

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