国際誌論文データベース

Ishii, T.（石井 辰典）, Kobayashi, M., & Watanabe, K. (2025).
Children’s religious belief in Japan: Relationships with empathy and parental belief.
日本の児童の宗教的信念：共感的関心と養育者の宗教的信念の役割
Psychology of Religion and Spirituality.
https://doi.org/10.1037/rel0000579

This preregistered study investigated whether children’s religious beliefs (RBs) are predicted by empathic concerns and parents’ religious beliefs. Participants included 166 Japanese children aged 6–12 years and their parents who visited a national museum. Participants were asked to complete a questionnaire that included measures of their religious beliefs and empathic concerns. Children’s religious beliefs were positively and independently explained by their empathic concern and parents’ religious beliefs even after controlling for parents’ empathic concern and demographic variables (age and gender). Bootstrapping analysis revealed that a positive association of this magnitude between children’s and parents’ beliefs rarely occurred among random pairs, indicating that factors within the familial context were the source of this association. These results support the two-factor hypothesis and highlight the importance of social cognitive abilities and vertical transmission in developing religious beliefs.

＊本研究の実施に当たり、日本科学未来館の皆様、早稲田大学理工学術院・渡邊克巳研究室の皆様に多大なサポートを頂きました。記して感謝申し上げます。
＊日本語での解説はこちら：https://x.gd/ULINS

Yamamoto, H.(山本仁志), Okada, I.(岡田勇), & Suzuki, T.(鈴木貴久) (2025).
Gradual reputation dynamics evolve and sustain cooperation in indirect reciprocity.
段階的な3値の評判ダイナミクスが間接互恵における協力を進化させ安定させる
PLoS One, 20(8), e0329742.
https://doi.org/10.1371/journal.pone.0329742

Humans have achieved widespread cooperation, largely sustained by mechanisms such as indirect reciprocity, which relies on reputation and social norms. People are highly motivated to maintain a good reputation, and social norms play a critical role in reputation systems by defining acceptable behavior, helping prevent exploitation by free-riders. However, there is a gap between theory and experiment in handling reputation information, with experiments often failing to capture the complexity that theoretical models propose. Here, we address two key issues: what kind of information is needed to define reputation as a social norm and the appropriate level of granularity required for reputation information to function effectively. This paper combines scenario-based experiments and evolutionary game theory to investigate the social norms individuals adopt in real-world settings, aiming to uncover the stability of these norms. Our results show that reputations should be categorized into three levels good, neutral, and bad. Results suggest gradual reputation dynamics that increase and decrease gradually due to cooperation or defection. However, a person’s reputation remains unchanged only when they defect against a bad reputation. Our experimental and theoretical results support critical insights into the dynamics of reputation and social norms within indirect reciprocity, challenging traditional binary reputational evaluations. The gradual nature of reputation updating and the use of nuanced evaluations provide a more realistic model of reputation dynamics.

Yamamoto, H.(山本仁志), Okada, I.(岡田勇), & Suzuki, T.(鈴木貴久) (2025).
Tolerant integrated reciprocity sustains cooperation in a noisy environment.
直接互恵と間接互恵の統合による寛容な戦略はエラーに対して頑健に協力を安定化する
Scientific Reports, 15(1), 28912.
https://doi.org/10.1038/s41598-025-14538-3

Human cooperation relies on both direct and indirect reciprocity. While these mechanisms are often treated as separate, real-world decision-making frequently involves integrating the two. However, the existing literature has paid limited attention to the contextual factors and mechanisms supporting the coexistence of direct and indirect reciprocity. This study proposes and analyses a model of integrated reciprocity that combines personal experiences with reputational information. Using agent-based simulations, we systematically and comprehensively evaluate social norms and demonstrate that tolerant integrated reciprocity, which incorporates a partner’s past behaviour and reputation, can sustain cooperation more robustly than strategies based solely on direct or indirect reciprocity. In particular, the combination of tolerant integrated reciprocity with the “Standing” norm maintains high cooperation levels even in noisy environments characterised by assessment and implementation errors. These findings suggest that tolerance and using multiple information sources provide an adaptive advantage in sustaining cooperation.

Krueger, F., Riedl, R., Bartz, J.A., Cook, K.S., Gefen, D., Hancock, P.A., Jarvenpaa, S.L., Krabbendam, L., Lee, M.R., Mayer, R.C., Mislin, A., Müller-Putz, G.R., Simpson, T., Takagishi, H.（高岸治人）, & Van Lange, P.A.M. (2025).
A call for transdisciplinary trust research in the artificial intelligence era.
AI時代における超学際的な信頼研究の必要性に関する提言
Humanities and Social Sciences Communications, 12, 1124.
https://doi.org/10.1057/s41599-025-05481-9

Trust is a cornerstone and enabler of human civilization, determining the very nature of how people interact with each other. The swift integration of artificial intelligence (AI) into daily life poses grand societal challenges and necessitates a reevaluation of trust. Our bibliometric literature review calls for scientists and stakeholders to cross traditional academic boundaries to address emerging and evolving societal challenges arising from AI. We propose a transdisciplinary research framework to understand and bolster trust in AI and address grand challenges in domains as diverse and urgent as misinformation, discrimination, and warfare.

信頼は、人類社会を成り立たせる土台であり、人と人との関わり方そのものを決める重要な要素です。ところが、AIが私たちの暮らしに急速に浸透したことで、社会は大きな課題に直面し、信頼のあり方を改めて考え直す必要が出てきました。私たちの文献レビューによると、AIがもたらす新しい社会問題に対応するには、研究者と実務家（行政・企業・市民など）が学問分野の壁を越えて協力することが欠かせません。そこで私たちは、AIへの信頼を理解し高めるための「超学際的（トランスディシプリナリー）」研究フレームワークを提案します。この枠組みは、誤情報の拡散、差別の助長、戦争への悪用など、緊急性の高い多様な課題に取り組むための道筋を示すものです。

Kowal, M., Sorokowski, P., … Ishii, T.（石井辰典）, … & Prazeres, F. (2025).
Cross-cultural data on romantic love and mate preferences from 117,293 participants across 175 countries.
175カ国・117,293人の参加者を対象とした、ロマンティックな愛とパートナー選択に関する文化比較データ
Scientific Data, 12, 1103.
https://doi.org/10.1038/s41597-025-05365-2

Psychological studies on close relationships have often overlooked cultural diversity, dynamic processes, and potentially universal principles that shape intimate partnerships. To address the limited generalizability of previous research and advance our understanding of romantic love experiences, mate preferences, and physical attractiveness, we conducted a large-scale cross-cultural survey study on these topics. A total of 404 researchers collected data in 45 languages from April to August 2021, involving 117,293 participants from 175 countries. Aside from standard demographic questions, the survey included valuable information on variables relevant to romantic relationships: intimate, passionate, and committed love within romantic relationships, physical-attractiveness enhancing behaviors, gender equality endorsement, collectivistic attitudes, personal history of pathogenic diseases, relationship quality, jealousy, personal involvement in sexual and/or emotional infidelity, relational mobility, mate preferences, and acceptance of sugar relationships. The resulting dataset provides a rich resource for investigating patterns within, and associations across, a broad range of variables relevant to romantic relationships, with extensive opportunities to analyze individual experiences worldwide.

調査票の日本語訳および日本でのデータ収集は、石井辰典（日本女子大学）・国里愛彦（専修大学）・遠山朝子（専修大学）・山田祐樹（九州大学）が担当しました（氏名はアルファベット順）。またこの活動に際し、日本心理学会「新型コロナウイルス感染拡大に関連した実践活動及び研究」の助成を受けました。

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.