Person:
Díaz Morales, Juan Francisco

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First Name
Juan Francisco
Last Name
Díaz Morales
URI
https://hdl.handle.net/20.500.14352/80114
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Psicología
Department
Psicología Social, Trabajo y Diferencial
Area
Personalidad, Evaluación y Tratamiento Psicológico
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2022 - 20232
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Author: Jankowski, Konrad S. × Has files: true ×

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Now showing 1 - 2 of 2
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    Chronotype, Time of Day, and Performance on Intelligence Tests in the School Setting
    (Journal of Intelligence, 2023) Jankowski, Konrad S.; Díaz Morales, Juan Francisco; Vollmer, Christian
    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.
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    Factors Underpinning the Shift to Eveningness during Early Adolescence: Pubertal Development and Family Conflicts
    (Journal of Youth and Adolescence, 2022) Díaz Morales, Juan Francisco; Escribano, Cristina; Puig Navarro, Yaiza; Jankowski, Konrad S.
    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 (49.9% boys) Spanish adolescents were assessed for pubertal development, family conflicts, and morningness/eveningness. The same measures were taken twice at the age of 12 and one year later (T1: M = 12.47, SD = 0.75 and T2: M = 13.64, SD = 0.78). Pubertal development and family conflicts were considered predictors of morningness/eveningness in a mixed-effects multilevel model. The developmental shift towards eveningness appeared in girls but not in boys. The shift was related to more advanced pubertal development and more conflicts in the family. This study has implications for shaping healthy sleep habits in adolescents and possible interventions focused on family dynamics.