国際誌論文データベース

Kido, Y. (貴堂雄太), & Takezawa, M. (竹澤正哲) (2025).
Empirical evidence for the spread of Cooperation through copying successful groups. 
成功集団の模倣による協力拡散：実証的証拠
Scientific Reports, 15, 22289.
https://doi.org/10.1038/s41598-025-07863-0

Large-scale cooperation among unrelated humans remains an evolutionary puzzle. Cultural group selection theory suggests that strong intergroup selection drives the evolution of cooperation, given substantial behavioral variation between groups. This study investigated payoff-biased imitation of successful out-groups as an intergroup selection process, specifically as an alternative to warfare-based mechanisms. We thus conducted two experiments manipulating exposure to cooperative out-group information in public goods games, demonstrating that cooperative behavior can indeed transmit across group boundaries, thereby influencing decision-making processes. However, this effect gradually diminished within groups, and transmitted cooperation was not likely to spread. Additionally, we performed a cross-cultural survey examining relationships between press freedom, which is a proxy for accessibility to out-group information, and different types of prosociality. The results revealed contrasting relationships, particularly in democratic countries: higher press freedom positively predicted impersonal prosociality (e.g., generalized trust) while negatively predicting personal prosociality (e.g., trust in family). These findings suggest that cultural processes such as payoff-biased imitation can facilitate the spread of cooperation beyond group boundaries, serving as a potential channel for intergroup selection. Finally, we discuss the implications for cultural group selection theory and additional mechanisms’ potential role in sustaining within-group cooperation.

Ueda, S. (上田皐介) & Yamagata, S. (2025).
Self-presentation of extraversion shifts all the Big Five personality traits in a socially desirable direction.
外向性の自己呈示はBig Fiveの全性格特性を社会的に望ましい方向に変化させる
International Journal of Personality Psychology, 11, 86–90. 
https://doi.org/10.21827/ijpp.11.42470

The internalization of self-presentation (IOSP; Tice, 1992) is a phenomenon where individuals internalize presented traits (e.g., extraversion) and shift the level of their traits in the presented direction. While IOSP predicts self-concept shifts only in the presented traits, this pre-registered study examined whether self-concepts of non-presented traits also shift in socially desirable directions. Based on statistical power analyses, 89 Japanese undergraduate students were recruited. They completed measures of the Big Five personality traits at two time points: 7–10 days prior to and immediately following a task where they wrote a self-introduction designed to convey an extraverted impression. Paired t-tests revealed shifts in all the Big Five traits in the predicted socially desirable directions (Cohen’s |dz| = .29–.36). These findings suggest that self-presentation of extraversion influences the self-concept of both presented and non-presented traits, challenging the current understanding of IOSP. Possible mechanisms underlying this phenomenon and implications for future research on personality change are discussed.

自己呈示の内在化（internalization of self-presentation, IOSP; Tice, 1992）とは、自己呈示した方向に自己概念が変化する現象である (e.g., 外向性の自己呈示を行うと，自身を外向的だと思うようになる)。IOSPでは、呈示された特性の自己概念のみが変化すると予測されるが、本研究では、自己呈示されていない特性においても社会的に望ましい方向への変化が生じるかを事前登録を行ったうえで検討した。検定力分析では87名が必要となり、日本人大学生89名が参加した。参加者は、外向的な印象を与えることを目的とした自己紹介文を作成する課題の実施前（7～10日前）と実施直後の2時点で、Big Five尺度に回答した。対応のあるt検定の結果、Big Fiveの全性格特性が社会的に望ましい方向に有意に変化した（Cohenの|dz| = .29～.36）。これらの結果は、外向性の自己呈示が、呈示された特性のみならず呈示されていない特性の自己概念にも影響を及ぼす可能性を示唆し、IOSPに関する従来の理解に再検討を促すものである。本研究では、この現象を生じさせうるメカニズムや、パーソナリティの変化 (personality change) に関する研究領域への示唆について議論した。

Niiya, Y. (新谷優), Yakin, S., Park, L. E., & Chang, Y.-H. (2025).
Nonzero-sum time perception is associated with greater willingness to help.
非ゼロサム的な時間の捉え方と援助行動意図との関連
European Journal of Investigation in Health, Psychology and Education, 15(5), 90.
https://doi.org/10.3390/ejihpe15050090

People are less likely to help others when they view time as a scarce resource. Does changing people’s perception of time influence their willingness to help? We hypothesized that people would be more willing to help and would allocate more time to helping others when they view time as a nonzero-sum resource (i.e., as a resource that merely exists or that can be created moment-by-moment with their interactions with others) versus a zero-sum resource (i.e., a commodity that can be lost, taken, or given away). Study 1 measured people’s perception of time and their willingness to help in hypothetical vignettes. Studies 2 and 3 manipulated the perception of time to examine its effect on people’s willingness to help others and the amount of time they wanted to spend helping. Study 3 further examined prosocial motivation as a potential mediator. Across the three studies, we demonstrated that when people perceive time as a nonzero-sum resource versus a zero-sum resource, people are more willing to help others. People’s prosocial motivation to reduce others’ distress mediated this relationship. We speculate that when people perceive time to be nonzero-sum, time spent helping others is not viewed as costly, but as a resource to invest in to benefit both themselves and others.

Tham, Y. J.(ターン有加里ジェシカ), Ohtsubo, Y. (大坪庸介), Hashimoto, T. (橋本剛明), & Karasawa, K. (唐沢かおり) (2025).
Equitable burden-sharing in “take-one-for-the-team” situations: The role of coordination.
誰かが皆のために動かなければいけない状況での公平な分担：調整の重要性
Journal of Experimental Psychology: General. Advance online publication.
https://doi.org/10.1037/xge0001781

Groups frequently encounter situations where someone must “take one for the team”—that is, one member must undertake a task for the benefit of the group. When such tasks recur, how should the burdens be shared? This question becomes particularly complex when the cost of performing the task varies among members, creating a trade-off between efficiency and equity. For instance, always assigning the task to the member who can complete it at the lowest cost is efficient but inequitable. Our research examines how this trade-off is managed, using the framework of social dilemmas, specifically volunteer’s dilemmas. Across three main experiments and three supplemental experiments (N = 1,789), we find that when participants imagine these situations, they prefer equitable (but inefficient) burden-sharing (Study 1). However, when they actually face these situations, their actions often deviate from this preference, with some members taking on more burdens than necessary to achieve equity (Study 2). Further investigation reveals that the main obstacle to equity is the difficulty of coordinating who takes on the task and when (Study 3). These findings contribute two key insights to research on fairness. First, they provide initial evidence that individuals tend to prefer equity when sharing indivisible burdens, contrasting with previous studies on distributive justice and social preferences, which have focused on divisible resources (e.g., money). Second, they highlight the critical role of coordination in achieving equitable burden-sharing—an aspect overlooked in prior research, which has focused on the role of coordination in group productivity rather than fairness.

https://psych.or.jp/publication/world109/pw22/

Takebe, M., (竹部成崇) & Nakashima, K. (中島健一郎) (in press). 
Testing the Mediating Role of Zero-Sum Beliefs in the Effect of Resource Scarcity on Out-Group Exclusion/Un-inclusion.
資源不足が外集団の排斥／受入拒否に及ぼす影響におけるゼロサム信念の媒介効果の検証
Japanese Psychological Research.
https://doi.org/10.1111/jpr.12576（Early View）

When resources are scarce, people often exclude/un-include others. However, the psychological process underlying this phenomenon is unclear. We tested the mediating role of zero-sum beliefs using vignette (Studies 1, 2, and 3) and priming (Study 4) experiments. In Studies 1, 2a, and 2b (n = 94, 206, and 508, respectively), via increased zero-sum beliefs, resource scarcity reduced the number of new employees to be hired (Study 1), increased opposition to accepting more foreign workers (Study 2a), and strengthened support for the return of foreign workers (Study 2b). In Study 3 (n = 132), suggesting that resources are non-zero-sum reduced the opposition to accepting more foreign workers via decreased zero-sum beliefs under resource scarcity. However, in Studies 1, 2a, and 3, zero-sum beliefs only had a partial mediating role; that is, the direct effects remained. In Studies 4a and 4b (n = 232 and 583, respectively), resource scarcity priming did not affect attitudes toward accepting more foreign workers via zero-sum beliefs. Future research directions are discussed.

Makino, K. (牧野圭子) (2018).
An empirical research framework for the aesthetic appreciation of the urban environment. 
都市環境の美的鑑賞に関する経験的研究の枠組み
City, Culture, and Society, 13, 1-7.
https://doi.org/10.1016/j.ccs.2017.06.001

The present article aims to construct an empirical research framework for the aesthetic appreciation of the urban environment. By applying the concept of “environmental aesthetics” to “consumer aesthetics,” the present article remarks that urban environments are considered as aesthetic environments when they resemble natural environments. This article proposes an empirical research framework composed of two factors. The first factor is the similarity of the urban environment to the natural environment. This factor is classified into two categories: (1) assimilation into the natural environment and (2) natural change caused by the passage of time. The second factor is the consumer’s relationship with the urban environment. This factor is also classified into two categories, borrowing the two terms of environmental aesthetics: (1) “engaged” and (2) “observational.” This article also discusses the research methods appropriate for this framework.

Kimura, K. （木村邦博） (2020). 
Japanese Women’s Attitudes Toward Childrearing: Text Analysis and Multidimensional Scaling.
子育てに対する日本女性の態度：テキスト分析と多次元尺度構成法
Advanced Studies in Behaviormetrics and Data Science: Essays in Honor of Akinori Okada, 423-438.
https://doi.org/10.1007/978-981-15-2700-5_26

This study aimed to understand Japanese women’s attitudes toward childrearing via text analysis. The text data were taken from the emails that readers had submitted to a magazine as a reply to the call for essays on the theme “Is Childrearing a Strain?” I hypothesized that Japanese women tended to attribute “failure” to external factors such as institutional flaws and “success” to internal factors such as their personal conditions. I employed an “appearance of strings” approach to natural language processing to map the keywords onto “topics.” Based on the multiple classification of emails with respect to the topics referred, I calculated symmetric and asymmetric versions of Jaccard Similarity Coefficient and applied four multidimensional scaling models: Torgerson’s method, SMACOF, slide vector model, and drift vector model. There was a contrast between positive and negative feelings. There were also personal, interpersonal, and societal facets. The emails expressing positive attitudes tended to refer to only personal topics, while those manifesting negative attitudes tended to refer to the topics in all the three facets. In the latter group of emails, reference to personal topics implied reference to interpersonal topics, and reference to interpersonal topics implied reference to societal topics.

Kimura, K. （木村邦博） (2020). 
Can the signaling game serve as a model of statistical discrimination in hiring?
シグナリングゲームは雇用における統計的差別のモデルたり得るか？
Sociological Theory and Methods, 35(1), 14-32.
https://doi.org/10.11218/ojjams.35.14

Some scholars argue that Spence’s signaling game with an index may serve as a model of statistical discrimination in hiring processes. This would then explain that both mean education level and mean wage are greater for men than for women in industrialized societies. To examine the validity of this conjecture, I formulated a generalized version of the game. In this version, I assumed that the educational level is a signal of productivity while the gender is an index of productivity. I then followed the refinement procedure of Perfect Bayesian Equilibria to eliminate unreasonable outcomes. My analysis reveals that an anomaly is derived from the separating equilibrium that survives the Intuitive Criterion in the procedure: the mean wage for men would be equivalent to that for women. As the employer is assumed to know that the educational cost for women is greater than that for men, he or she would believe that women with a lower level of education have the same productivity as men with a higher level of education. Therefore, the employer would offer the same wage for the men and the women. I also examined other classes of equilibria and alternative assumptions.

Yang, F.（楊帆）, & Oshio, A.（小塩真司） (2025). 
Using attachment theory to conceptualize and measure the experiences in human-AI relationships. 
人とAIの関係性における体験を愛着理論で概念化・測定する試み
Current Psychology.
https://doi.org/10.1007/s12144-025-07917-6

Artificial intelligence (AI) is growing “stronger and wiser,” leading to increasingly frequent and varied human-AI interactions. This trend is expected to continue. Existing research has primarily focused on trust and companionship in human-AI relationships, but little is known about whether attachment-related functions and experiences could also be applied to this relationship. In two pilot studies and one formal study, the current project first explored using attachment theory to examine human-AI relationships. Initially, we hypothesized that interactions with generative AI mimic attachment-related functions, which we tested in Pilot Study 1. Subsequently, we posited that experiences in human-AI relationships could be conceptualized via two attachment dimensions, attachment anxiety and avoidance, which are similar to traditional interpersonal dynamics. To this end, in Pilot Study 2, a self-report scale, the Experiences in Human-AI Relationships Scale, was developed. Further, we tested its reliability and validity in a formal study. Overall, the findings suggest that attachment theory significantly contributes to understanding the dynamics of human-AI interactions. Specifically, attachment anxiety toward AI is characterized by a significant need for emotional reassurance from AI and a fear of receiving inadequate responses. Conversely, attachment avoidance involves discomfort with closeness and a preference for maintaining emotional distance from AI. This implies the potential existence of shared structures underlying the experiences generated from interactions, including those with other humans, pets, or AI. These patterns reveal similarities with human and pet relationships, suggesting common structural foundations. Future research should examine how these attachment styles function across different relational contexts.

AIは本当に愛着対象になり得るのか。本研究では、中国の若者を対象に調査を行い、約半数がAIを「近接追求」「安全避難所」「安全基地」として利用していることが示唆された。 人とAIの関係は一方向的であり、物理的接触も存在しないが、その心理的体験は愛着理論によって説明可能であり、新たな対人理解の枠組みとなり得る。 本研究は、AIへの「真の愛着」が成立していると主張するものではない。むしろ、AIとのやり取りにおいて生じる体験が、構造的に愛着理論によって捉えうることを示した。「人間らしいAI」の追求と並行して、AIがもつ感情操作の力が引き起こす社会的影響にも真剣に向き合う必要がある。

Yang, F.（楊帆）& Oshio, A.（小塩真司） (2025).
The mediating role of mindfulness between attachment style and self-concept clarity within a dyadic context. 
二者間関係における愛着スタイルと自己概念明確性との間におけるマインドフルネスの媒介効果
Current Issues in Personality Psychology.
https://doi.org/10.5114/cipp/197265

Previous research has found that attachment style is associated with self-concept clarity, and mindfulness mediates this association at an individual level. However, there is currently a lack of research on the relationship between attachment style, mindfulness, and self-concept clarity from an interpersonal perspective. Therefore, the current study aimed to extend the relationship between attachment style and self-concept clarity to a dyadic context. To this end, we online recruited a final sample of 773 pairs of Chinese heterosexual couples (Mage = 35.43, SDage = 3.77 for wives; Mage = 37.46, SDage = 4.39 for husbands) to measure their attachment style, mindfulness, and self-concept clarity and conducted the actor-partner interdependence mediation modeling. Results indicate actor effects that one’s own mindfulness significantly mediated the relationship between one’s own attachment style (both avoidance and anxiety) and self-concept clarity for both women and men. Furthermore, as for the partner effect, the mindfulness of men significantly mediated the relationship between the attachment anxiety of women and the self-concept clarity of men. Altogether, we provide evidence that the impact of attachment style on self-concept clarity within a dyadic context and the level of husbands’ mindfulness could partly explain the relationship between wives’ attachment anxiety and husbands’ self-concept clarity. Implications of these findings are discussed.