Published papers

© 2020 Elsevier Ltd This study examined associations of the General Factor of Personality (GFP) with trait emotional intelligence (EI) and emotional and behavioral problems in Japanese children and adolescents. We used self- and parent-rated personality data to extract the two GFPs using the Ten Item Personality Inventory. Participants were 10,357 Japanese children and adolescents (M = 13.99 years; SD = 2.53; range 9–18; 5177 boys, 5168 girls, 12 unknown). Correlational and multiple regression analyses revealed that the two GFPs were significantly associated with trait EI. However, the association between the self-rated GFP and trait EI was weaker than previously reported. The GFPs were also associated with emotional and behavioral problems in children and adolescents above and beyond trait EI. These findings support the notion that the GFP reflects social effectiveness and imply differences in the GFP-trait EI association between youths and adults.

It was originally hypothesized by Block that what has come to be known as the General Factor of Personality (GFP) reflects ego-resiliency. We test Block’s hypothesis in two studies. In Study 1 a meta-analysis (N = 15,609) examining the relationship between the GFP and ego-resiliency/resilience was conducted. In Study 2 (N = 157) archival data from Block and Block was used to examine the association between rater judged ego-resiliency across childhood, adolescence, and into early adulthood and the GFP based on self-report in early adulthood. Using structural equation modeling for the meta-analytic data, the correlation between the GFP and ego-resiliency/resilience was estimated at r = 0.93. Using a trait-state occasion model to test the hypothesis in Study 2, the correlation between the GFP and rated ego-resiliency was estimated at r = 0.85. The results of the two studies offer substantial support for Block’s original hypothesis. Given the strength of the associations between the GFP and ego-resiliency/resilience one may conclude that the two constructs largely reflect the same underlying phenomenon.

The purpose of this study was to validate the 20-item Mini-K scale, which is the short form of the Arizona Life History Battery, as translated into Japanese. Two samples of Japanese adults (N=2000; 50.0% men; Mage=40.9 for the first survey; N=400; 50.0% men; Mage=42.2 for the second survey) completed a web-based questionnaire, including the Japanese translation of the Mini-K. The results showed that the psychometric properties of the Japanese Mini-K scale were comparable to those of the original English version. The scale had good reliability based on Cronbach's and McDonald's . Convergent validity was demonstrated by the correlation between the Mini-K scores and life history indicators. In addition, the Mini-K score was related to both personality and psychosomatic health. The translated scale provides a valid and reliable instrument in Japanese that measures human life-history strategy.

This study explored the effects of age and gender on the mean levels of Big Five personality traits in Japanese adulthood. The data for the present study were drawn from a large cross-sectional study. The participants were 4,588 adults (2,476 women, M age＝53.5 years, SD age＝12.9, age range: 23–79 years), and the analyzed measure was a Japanese version of the Ten-Item Personality Inventory (TIPI-J; Oshio, Abe, & Cutrone, 2012). Multiple regression analyses were carried out to determine the effects of age, gender, and the interaction between the two on each Big Five scale. Age differences were found suggesting that agreeableness and conscientiousness are positively associated with age. Gender differences were also found suggesting that females have higher levels of extraversion, while males are more open to experience. An Age×Sex effect was confirmed only on neuroticism, indicating that younger females' level of neuroticism is significantly higher than males, but older females' level is lower and is at the same level as males.

The purpose of this study was to explore University of Tokyo students' socioemotional development in relation to their experiential activities. Participants were 276 university students (164 males, 106 females, 6 unreported). Their mean age at the time of first assessment was 20.46 years (SD＝1.43, Median＝20, range 18–27). Personality traits, sense of coherence, and emotion regulation strategies were assessed, and analyses were conducted for rank-order stability, mean-level change, and individual differences in change of students' personality traits and sense of coherence. The results showed that rank-order stability was relatively high. As for mean-level change, scores for extraversion and sense of coherence increased significantly. In addition, individual differences in changes of these traits were accounted by students' emotion regulation strategies. Specifically, students using more positive reappraisal strategies showed more increase in their extraversion scores. In contrast, students using more acceptance strategies showed more decline in extraversion. These findings indicate that extracurricular activities like experiential activities may have effects on the socioemotional development of university students.

This study explored the association between multidimensional identity and multiple social relationships in emerging adults. Participants were 385 students (210 men, 175 women, M＝22.4, SD＝2.4, range: 18–29 years). Identity was assessed with the Multidimensional Ego Identity Scale (Tani, 2001). Attachment to their parents, friends, and romantic partners were assessed as the key social relationships of the participants, by the Experiences in Close Relationship Questionnaire-Revised (Fraley, Waller, & Brennan, 2000). The effects of age, gender, and social relationships on each identity dimension were estimated as follows by structural equation modeling. Attachment to parents had an effect on the Self-Sameness and Continuity dimension; age had an effect on the Self Identity dimension; attachment to friends and romantic partners had an effect on the Interpersonal Identity dimension; and age and attachment to friends had an effect on the Psychosocial Identity dimension. These results indicate that the internal aspect of identity is associated with one's relationships to parents, while the social aspect of identity is associated with relationships to friends and romantic partners.

Considerable research has been performed on the association between sibling composition and various characteristics, including personality, intelligence, and social attitudes. These studies suggest that birth order among siblings could weakly but significantly affect the development of personality traits and intelligence. However, few studies on the association between sibling composition and moral foundations have been conducted. Therefore, the present study investigated whether sibling composition (only child, firstborn, laterborn) is related to moral values with a between-family design. A sample of 500 Japanese adults (250 women) completed the self-administered online questionnaire. The mean age was 45.42 years (SD = 8.53, range = 20–60, median = 46). The general linear model was used to test the association between sibling composition and moral values. The results showed no differences in five moral foundation and two higher-order moral dimension scores between firstborns and laterborns. However, only children scored lower on care/harm, fairness/cheating, and individualizing foundation than laterborns. This finding might indicate that growing up with their siblings positively affects the development of care/harm and fairness/cheating (individualizing foundation) regardless of one's position among those siblings.

This study investigated the age differences in the Dark Triad (DT) traits with 2 independent samples. Personality was measured using the Short Dark Triad and the Dark Triad Ditty Dozen. Results showed a significant negative correlation between age and DT traits except for narcissism, which differed between the samples. Significant age-by-sex interaction effects were observed for Macitiavellianism and the DT composite score, indicating that women showed a steeper downward age trend in dark personalities.

Little research has been conducted on personality development in non-Western countries. The present study investigated age differences in personality in Japanese middle adults (N = 2000; M = 40.94 years; SD = 5.35, range 30-49; 1000 women). After controlling for educational level, annual income, marital status, and gender, it was found that the level of Emotionality was negatively associated with age. Honesty-Humility, on the other hand, was positively associated with age. However, Extraversion, Agreeableness, Conscientiousness, and Openness were not associated with the participant age. These findings suggest that trends in personality development may differ slightly between Western and non-Western countries. (C) 2016 Elsevier Inc. All rights reserved.

In this study, we conducted the translation and validation of the K-SF-42 in Japan (Figueredo, 2017). The K-SF-42 is a new short form of the Arizona Life History Battery. We obtained empirical evidence that the original seven-factor structure could be applied to the Japanese translated version of K-SF-42 (K-SF-42-J). We also observed good internal consistency of the seven scales of K-SF-42-J. The multi-group confirmatory factor analysis findings suggest that the K-SF-42-J can be used in both sexes and diverse age groups. The K-SF-42-J scales showed similar correlates as the English original, with higher scores of other life history strategy measurement, trait emotional intelligence, well-being, and cultural and social resources in childhood. Use of the K-SF-42-J will allow researchers with Japanese speaking samples to integrate their findings with the existing life history strategy research literature. The brevity of the K-SF-42-J will be appealing to researchers who are concerned about taxing the time and motivation of their participants.

The purpose of this study was to validate the 7-item long-term mating orientation scale (LTMO) as translated into Japanese. Two samples of Japanese adults (N=2000; 50.0% male; Mage=40.9 for the first survey; N=300; 54.7% male; Mage=42.4 for the second survey) completed a web-based questionnaire, including the Japanese translation of the LTMO. The results showed that the psychometric properties of the Japanese LTMO scale were comparable to those of the original English version. The scale had adequate reliability based on Cronbach's and McDonald's . Convergent validity was demonstrated by the correlation between the LTMO scores and related variables: human life history strategies, short-term sociosexual orientation, attitude to infidelity, romantic attachment style, and so on. The translated scale provides a valid and reliable instrument in Japanese that measures human mating strategy.