The purpose of the present study was to develop a scale for measuring motivation in school-based extracurricular activities/clubs based on organismic integration theory, and to examine the relationship between students’ motivation and instructors’ leadership. In study 1, 304 high school students completed the questionnaire. The results of an explanatory factor analysis identified 5 factors: intrinsic regulation, identified regulation, introjected regulation, external regulation, and non-regulation. In study 2, 870 high school students completed the questionnaire. The results of multilevel analyses indicated that the instructors’ leadership to maintain interpersonal relations and guide club members was positively correlated with students’ intrinsic regulation and identified regulation, and negatively correlated with their non-regulation. Furthermore, the results indicated that students’ perception of their instructors’ leadership to maintain interpersonal relations and guide club members was positively correlated with students’ intrinsic regulation and identified regulation, and negatively correlated with their non-regulation.

It has been shown that people tend to view opponents as biased. Recent theoretical studies showed that this tendency occurs due to naïve realism. People tend to be overconfident about their objectivity ─ they believe they see the world as it really is (Naïve realism: Ross & Ward, 1995) ─ hence, they assume that people who have a different view must be biased (Pronin et al., 2004). This study examines the effect of encountering clear demonstrations that personal sensory perceptions are not necessarily accurate on the perception of opponents’ bias in their social judgment through exposure to visual illusions. A total of 87 participants were grouped by whether or not they experienced visual illusions. Participants who experienced visual illusions rated opponents as having fewer biases in their social judgments than participants who did not experience visual illusions. This suggested that a person’s overconfidence in their own perception ─ “I see the world as it really is” ─ might be one of the causes of people’s negative perception of opponents.

The Pathological Narcissism Inventory (PNI), consisting of 7 sub-scales, was developed to comprehensively assess the components of narcissism, including not only grandiose but also vulnerable aspects. The purpose of this study was to develop the Japanese version of the Pathological Narcissism Inventory (PNI-J) and to examine its factor structure, reliability, and validity in the Japanese population. The results from 402 participants showed that the PNI-J has a factor structure that is nearly equivalent to the original PNI. Furthermore, the PNI-J had good test-retest reliability, and had a theoretically reasonable correlation with self-, interpersonal-, and personality-related variables. Additionally, the Japanese version of the Brief-Pathological Narcissism Inventory (B-PNI-J) was constructed based on previous research, demonstrating nearly the same properties as the full version. Thus, the PNI-J and the B-PNI-J can reflect the pathological features of narcissistic people in the Japanese population more comprehensively than other conventional measurement scales of narcissism.

This study investigated the reliability and validity of the Japanese versions of the Fear of Happiness Scale and the Fragility of Happiness Scale. The scales were administered to 341 Japanese undergraduates. Confirmatory factor analysis showed that, like the original versions, the Japanese Fear of Happiness Scale and the Fragility of Happiness Scale each had a one-factor structure. The two scales also each had good internal consistency, test-retest reliability, and construct validity. Furthermore, the scales showed incremental validity by predicting psychological elements (life satisfaction, depression, anxiety, stress) better than the behavioral inhibition system (BIS) and the behavioral activation system (BAS). The results of the present study revealed that the Fear of Happiness Scale and the Fragility of Happiness Scale had an adequate reliability and validity in this Japanese group.

The present study compared two forms of reciprocity, namely, a selfish versus altruistic one. In two experiments, participants played two rounds of the dictator game. In the first round, they were all assigned the “recipient” role, and were either over- or under-benefited by the game partner in the “allocator” role. In the second round, the participants were instead assigned the allocator role, with the recipient being either the same partner from the first round or a new partner. The results consistently showed that those who had under-benefited in the first round in turn over-benefited in the second round, regardless of whether the partner remained the same or was replaced. In contrast, those who had over-benefited previously returned the favor, but this was the case only toward the same partner rather than the new one. Hence, selfish behavior was generalized to strangers, whereas a (an altruistic) favor was not generalized, being returned only to the original benefactor. Implications of the asymmetry in chain reactions, as well as methodological issues, are discussed.

A previous study revealed curvilinear changes over time in 12 traits of the Yatabe-Guilford Personality Inventory in Japan (Oshio et al., 2019). The purpose of the present study was to examine relationships between the survey-year change of the inventory and social indices. A cross-temporal meta-analysis was conducted on 171 to 181 samples (68 to 74 papers) of Japanese undergraduates who completed the inventory from 1957 to 2012 (total N = 29,524–29,847). The dataset was partially identical to the previous study. Partial correlation with previous control scores of personality traits indicated that mean scores for seven personality traits are associated with changes in social indices. Results of time series analyses indicated that the change of social indices has significant associations with the following mean score changes of personality traits. Implications of the results are discussed.

The potential use of insects as a novel food resource has recently attracted a great deal of attention because of their environmental and nutritional benefits. Nevertheless, despite growing interest in the use of insects as food, residents of economically developed countries tend not to accept insect-based foods. This study reviewed earlier reports of the literature of consumer acceptance of insect-based foods. Based on the literatures, this review established a theoretical model of acceptance of insect-based foods. Sensory attributes (e.g., taste, smell, appearance) and cognitive attributes (e.g., nutritional value, environmental benefits), and individual traits (e.g., gender, food neophobia, sensation seeking) might influence the acceptance of insect-based foods via emotional processing (e.g., disgust, anxiety, excitement, curiosity). The practical implications for industries and future prospects are discussed.