Juan F. Díaz-Morales

Juan F. Díaz-Morales
Complutense University of Madrid | UCM · Department of Personality, Evaluation and Psychological Treatment II (Individual Differences and Work Psychology)

PhD, MD

About

126
Publications
138,241
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
4,293
Citations
Introduction
Juan F. is working at Faculty of Psychology of Complutense University of Madrid, on individual differences (chronopsychology, personality, intelligence, and gender studies). - Scholar Academic (Google): http://scholar.google.es/citations?user=PGRi3EwAAAAJ&hl=es; - ResearcherID Profile (Thomson Reuters): http://www.researcherid.com/rid/A-7797-2010; - Personal web (Complutense University): https://www.ucm.es/jfdiazmorales/
Additional affiliations
February 2002 - present
Complutense University of Madrid
Position
  • Individual Differences
January 2002 - present
Complutense University of Madrid
Position
  • Individual Differences

Publications

Publications (126)
Article
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 a...
Article
Full-text available
Evening preference has recently been identified as a risk factor for depression and anxiety. In this study, the relationship between anxiety, morningness–eveningness and sleep habits were examined during adolescence. Adolescents aged 12–16 years (n = 1406; 50.9 % girls) completed the Morningness–Eveningness Scale for Children, the State-Trait Anxie...
Article
Full-text available
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. Additi...
Article
Full-text available
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...
Article
Full-text available
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 two days in order to test how chronotype and time-of-day are related to mood during the school...
Article
Full-text available
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 ( M = 31.90, SD = 12.12) who comple...
Article
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 app...
Article
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 univers...
Article
Full-text available
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 studi...
Article
Full-text available
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 adoles...
Article
Birding specialization can be measured alongside a continuum from the beginner to the specialist. The structure of birding specialization has three dimensions: (1) skill/knowledge, (2) behavior, and (3) psychological commitment. We tested the factorial structure and factorial invariance of the birding specialization scale in traditional and simplif...
Article
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; M = 14.8, SD = 1.99) who completed the MESSi, the Morningness Eveningness Scale of Children (MESC), ques...
Article
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. This study aimed to test sex differences in the M/E, mood, a...
Article
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. This study aimed to test sex differences in the M/E, mood, a...
Article
Full-text available
The aim was to analyze the morningness/eveningness (M/E) effect on suicidal ideation through sleep and depressive symptoms mediators with school shift (i.e., morning and afternoon) as moderator. In this study, 586 Mexican adolescents, with a mean age of 16.31 ± 0.92, from a public high school in a double-shift school system (298 from the morning sh...
Article
The Composite Scale of Morningness (CSM) is a self-report measure of circadian preference that is related with one’s physical and mental health. This study aimed to explore the psychometric properties of the Bangla version of the CSM and validate it with sleep habits, BRUnel Mood Scale (BRUMS) and Positive Mental Health Scale (PMH-scale). The sampl...
Article
In this study, the day-of-week effect on positive and negative affect, taking into account the moderating effect of chronotype, sleep length and sex, was analyzed. Ninety-four adolescents (16.1 ± 1.24 years old) attending high schools in the morning filled out diaries to assess the natural day-to-day fluctuations in mood and sleep. Using multilevel...
Article
Spain is one of the countries with the highest number of Covid-19 cases per habitant. On March 14, 2020, the Government declared the State of Alarm which included the mandatory confinement of all citizens. On March 30 and April 11, we surveyed 1659 adults to research the relevance of social/work status and personality variables in the prediction of...
Article
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 = 0.70 y, from 4th, 5th and 6th grades) in Reynosa, Tamaulipas, in northeastern Mexi...
Article
Full-text available
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 qualit...
Article
Full-text available
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,...
Article
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 bot...
Article
Full-text available
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...
Article
Full-text available
People choosing a pet have a number of factors to consider. The important one is whether a pet can synchronize with humans in sleep timing. Chronotype reflects individual differences in sleep timing. Social jetlag referring to a misalignment of ones’ own biological (internal) time compared to the social time reflects variability in sleep timing bet...
Article
Full-text available
Given the known relationship between eveningness and sociosexuality among females, the aims of this study were: (a) to analyze this relationship in four countries using midsleep time on free days and morning affect measures of morningness–eveningness and (b) to test the role of dark personality andother relevant control variables in this relationsh...
Article
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)...
Chapter
The importance of gender in understanding health practices and cases of illness is increasingly recognized, and key to this chapter is a better understanding of the application of gender approaches to women’s and men’s health. First, the Gender and Health section describes how the influence of sex and gender on health has been analyzed. Second, the...
Article
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 vali...
Article
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 = 12.01) who filled out measures of Morningness-Eveningness (MESSi and CSM), sleep ha...
Article
Full-text available
Morningness–eveningness and sleep habits relationship were studied between Mexican and Spanish adolescents. A total sample of 611 Mexican and Spanish adolescents (13–15 years old; 14.12 ± 0.75) participated in this comparative study and filled out the preferred timing of sleep and activity using item 19 of Morningness–Eveningness Questionnaire and...
Article
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...
Article
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. Comparing incre...
Article
Full-text available
The aim of this study was to analyze the psychometric properties of the widely used general procrastination, decisional procrastination, and adult inventory of procrastination scales in both undergraduate and adult Polish populations. Polish versions of these scales were filled out by 390 student and 513 adult participants. Principal component anal...
Article
Full-text available
Morningness-eveningness is the preference for different times of day for activity and sleep. Here, we addressed the effects of sleep behaviour and morningness-eveningness on sociosexuality. Three hundred students (mean age 22.75 years, with 95% between 18 and 28) participated online, answering questions about morningness-eveningness (rMEQ), mid-poi...
Article
Full-text available
The increasing interest in the way in which morningness-eveningness affects psychological functioning is remarkable in recent years. Accumulating evidence demonstrates that time of day preferences and sleep habits have an influence on cognitive and school performance and adolescent's health. Our research team has been analysing the role of chronoty...
Article
Full-text available
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)....
Chapter
Full-text available
This chapter summarises some results of the International Time Perspective Research Project, which is a collaborative cross-cultural study of time perspective carried out in 24 countries. The highlights of structural equivalence assessment study are presented, showing the cross-cultural invariance of 36 items of the Zimbardo Time Perspective Invent...
Article
Full-text available
The interest in the extent to which time-of-day preferences affect school performance is increasing. Apart from biological factors, Morning and Evening types differ in their lifestyle and personality traits which may have implications into diverse areas such as their motivation to learn. Taking into account available data, the aim of the present st...
Chapter
Full-text available
One negative consequence related to poor future planned behaviour is chronic procrastination, the purposive and frequent delay in beginning or completing a task to the point of experiencing subjective discomfort. Although shown to be associated to affective, behavioral, and cognitive characteristics reflecting more than inefficient time management,...
Article
Full-text available
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 behavio...
Article
Full-text available
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 24:0...
Article
Full-text available
This review provides an overview of the role of circadian prefer-ence in psychological functioning of adolescents taking into account their shift to eveningness during this stage of life. After a brief explanation about morningness/eveningness and other terms related, an overview of the changes that occur on three of the most important areas in the...
Article
Full-text available
Education on sleep hygiene improves sleep knowledge. However, the literature shows that improvements in adolescents’ sleep hygiene behaviour are less convincing. We developed an educational intervention for 6th graders based on self-determination theory and evaluated this program in a pre-post-design with a control group. Pre-test was one week befo...
Article
Full-text available
Sociosexual orientation is a construct describing the propensity to engage in casual sex and sexual activity in uncommitted relationships, varying from restricted to unrestricted orientation. The personality profile of people exhibiting unrestricted sociosexuality matches a personality profile related to eveningness. Previous research on sociosexua...
Article
Full-text available
The use of self-reported grades in psychological research may be necessary since sometimes it is not possible to obtain school transcripts. This study analyses the accuracy of self-reported grades among Spanish high-school students considering actual level of achievement, sex/gender, and age. Results indicate that high-school students tended to ove...
Article
Full-text available
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 towards eveningness during the age of puberty have been considered only separately. I...
Article
Full-text available
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...
Article
Full-text available
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 a...
Article
Full-text available
Article 515686S GOXXX10.1177/2158244013515686Sircova et al.Sircova et al. 9 , & 54 members of the International Time Perspective Research Project (presented in alphabetical order by country): Slimane Djarallah 10 , Mohamed Seghir Chorfi 11 , Umbelina do Rego Leite 12 , Hui Lin 13 , Houchao Lv 14 , Tomislav Bunjevac 15 , Tena Tomaš 15 , Jasmina Pune...
Article
Full-text available
In this article, we assess the structural equivalence of the Zimbardo Time Perspective Inventory (ZTPI) across 26 samples from 24 countries (N = 12,200). The ZTPI is proven to be a valid and reliable index of individual differences in time perspective across five temporal categories: Past Negative, Past Positive, Present Fatalistic, Present Hedonis...
Article
Full-text available
Research relating procrastination and mental health suggests that poor adjustment may be explained directly by the stress resulted from worry/anxiety over the delay, and indirectly by the tendency to put off important coping behaviors. In the present study, participants (80 women, 24 men; age range = 18-33 years, M age = 21.12 years old, SD = 2.03)...
Chapter
Full-text available
El objetivo de este capítulo es proporcionar algunas recomendaciones sobre cómo incorporar la Perspectiva de Género (PG) en la investigación, realizando acciones sensibles al género a lo largo de las distintas fases de investigación. En primer lugar, se plantean algunas cuestiones sobre el género y la salud, principalmente en cuanto a los tipos de...
Article
Full-text available
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 pro...
Article
Full-text available
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...
Article
Full-text available
Optimal performance depends, among others, on two factors related to time preferred: a) synchrony between time of day at which the task is performed and pupil’s chronotype (morning- or evening-type), and b) getting adequate sleep time. Because of school schedules are mostly in the morning, evening-type adolescents may obtain worse school performanc...
Article
Full-text available
El sobreentrenamiento aparece en deportistas cuando el desgaste propio del entrenamiento se hace extremo y se bloquean los procesos de recuperación (Kellman, 2002). De modo similar, los artistas padecen problemas derivados de su ocupación y estilo de vida. La constante demanda de perfección, los largos periodos de entrenamiento, la competencia y la...
Article
Los músicos padecen problemas derivadosde su ocupación y estilo de vida. Unadedicación excesiva a la práctica musicalpuede tener consecuencias similaresa las que experimentan deportistas cuandoel desgaste propio del entrenamientose hace extremo y se bloquean los procesosde recuperación (agotamiento osobreentrenamiento). Dada la elevadadedicación qu...
Article
Full-text available
Adolescents move to evening orientation just when school schedule becomes earlier. Whereas school achievement has been associated to morningness orientation during morning school schedule, some studies have indicated that evening people are more intelligent. In this study the relative contribution of Morningness–Eveningness (M–E) in the prediction...
Article
Full-text available
The relationship between morningness-eveningness and anxiety trait among adolescents was studied. Six hundred thirty eight adolescents between 12 and 14 years old participated in this study. Morningness-eveningness was measured by the Morningness-Eveningness Scale for Children, MESC (Carskadon, Vieira & Acebo, 1993) and anxiety trait was measured b...
Chapter
Full-text available
One negative consequence related to poor future planned behaviour is chronic procrastination, the purposive and frequent delay in beginning or completing a task to the point of experiencing subjective discomfort. Although shown to be associated to affective, behavioral, and cognitive characteristics reflecting more than inefficient time management,...
Article
Full-text available
Optimal performance depends, among others, on two factors related to time preferred: a) synchrony between time of day at which the task is performed and pupil's chronotype (morning- or evening-type), and b) getting adequate sleep time. Because of school schedules are mostly in the morning, evening-type adolescents may obtain worse school performanc...
Article
Full-text available
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 year...
Article
Full-text available
Knowledge of the sleep beliefs among adolescents is relevant in order to promote primary prevention of unhealthy lifestyles related to sleep hygiene. In study 1, sleep beliefs among 11–16-years-old adolescents were explored according to gender, age, and chronotype. Adolescents completed the Sleep Beliefs Scale (SBS; Adan A, Fabbri M, Natale V, Prat...
Article
Full-text available
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 relationsh...
Article
Full-text available
There are few studies suggesting that chronotype or morningness-eveningness (M/E) is a predictor of depressive symptoms. A sample of 277 women (university students) of a mean age of 22.25 years ± (SD) 2.47 participated in this study. We used the Composite Scale of Morningness to assess circadian typology, the Patient Health Questionnaire (PHQ-9) to...
Article
Full-text available
RESUMEN: El optimismo se presenta como una variable importante a estudiar para comprender las características psicológicas asociadas al máximo rendimiento. Algunos trabajos destacan una relación positiva entre el optimismo, el rendimiento y la edad de los deportistas, aunque se requieren más investigaciones al respecto. Teniendo en cuenta los aspec...
Article
Full-text available
Recently, it has been demonstrated that attitudes toward an organization impact upon sustained volunteerism. We compared Spanish and Italian volunteers using the Organizational Commitment Questionnaire (OCQ) and then investigated how organizational commitment related to the intention to remain in the organization. Confirmatory and multiple-groups c...
Article
Full-text available
Students currently enrolled in gerontology studies in professional schools, as well as aging network personnel pursuing advanced certificates in gerontology require a broadened perspective and knowledge base for advancing volunteer services in behalf of older citizens. This paper describes an innovative Gerontology Career Preparation Program in gra...
Article
Full-text available
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 verba...
Article
Full-text available
This work has explored the socioemotional selectivity theory (Cartensen, 1995) with the purpose of evaluating how people selectively optimize their activities involving social investments as they increase in age, investing more in self-relevant and emotionally meaningful goals. Specifically, the purpose of this study was to test hypotheses derived...
Article
Full-text available
Assortative mating in temperament and intelligence, and the role of marital satisfaction. 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 assorta...
Article
El emparejamiento selectivo se refiere a la unión de pares de individuos más semejantes de lo que cabría esperar por azar. En este estudio se han analizado, en parejas adultas, varias hipótesis sobre emparejamiento selectivo: hipótesis de la semejanza (o complementariedad), homogamia social y convergencia. Una vez analizado el tipo de emparejamient...
Article
Full-text available
Given that personality aspects of procrastinators are a consequence of their coping with environmental and social demands, we examined the extent that avoidant procrastination was related to personality styles from the Millon’s personality model. In the current study 1027 Spanish adults self-reported motivational, cognitive and behavioral personali...
Article
El propósito de este estudio es analizarlas relaciones entre la salud física y psicológicaen función del género y determinarsi esa relación cambia cuando lossujetos son analizados en función de susituación laboral (trabajadores, desempleadoso amas de casa). La muestra erade 1500 personas representativas de lapoblación española y que pertenecían ala...
Article
Full-text available
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. Res...
Article
Full-text available
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...
Article
Full-text available
Abstract People’s health and well-being may be determined by the interaction of endogenous and external rhythms. Late chronotypes should become anxious because of the demand to perform tasks in a society oriented preferentially to morning work. In this study, we examined the relationship between morningness and anxiety in 559 adults (age range 40–6...
Article
Full-text available
Individual differences in human biological rhythms and diurnal preference (morningness-eveningness) are often based on self-report scales. Here, we compare Spanish (N = 771) and German (N = 1,182) adolescents (12–18 years) using the Composite Scale of Morningness (CSM). A 3-factorial solution of the CSM was supported in both countries, morningness,...