著者
林 直保子 神 信人 山岸 俊男
出版者
日本社会心理学会
雑誌
社会心理学研究 (ISSN:09161503)
巻号頁・発行日
vol.8, no.1, pp.33-43, 1993-01-22 (Released:2016-12-01)

The main purpose of this study was to examine how the existence of multiple Prisoner's Dilemma relations among group members affects their choices in each PD relation. Twenty-eight computer simulated actors were used to simulate group members. Each simulated-actor had two kinds of strategies: (1) designation strategy (i.e., strategy to determine whom to choose as a game partner), and (2) behavior strategy (i.e., strategy to determine when to cooperate and when to defect). The simulation involved four designation strategies, and seven behavior strategies. Five of behavior strategies were variants of the tit-for tat strategy, said to be most effective in iterated 2-person PD games. Results of the simulation indicate that: (1) the designation strategy has a greater influence on the simulated-actor' total score than the behavior strategy; (2) effectiveness of the behavior strategy changes depending on the designation strategy adopted; (3) the relationship between disignation and behavior strategies mentioned above depends on the nature of the pay-off matrix used in each game played along the PD network.
著者
神 信人
出版者
淑徳大学
雑誌
若手研究(B)
巻号頁・発行日
2004

平成18年度には、17年度に開発したリーダー制裁行動進化シミュレーションにおけるリーダー進化replicator dynamicsのアルゴリズムを改善した。このシミュレーションでは、社会的ジレンマに直面している各集団に成員への制裁権限を担うリーダーが1人いて、それぞれの持つ行動傾向に応じ、非協力成員やリーダーを支援しない成員を罰するかどうかを決定する状況を想定している。このリーダーのreplicator dynamicsは、集団成員の支援からなる「リーダー個人の利得」と「集団成員の合計利得」という2つの利得に基づいている。前者はリーダー自ら辞任する場合、後者は解任される場合のリーダー交替にそれぞれ対応する。17年度のプログラムでは、二つの利得のどちらが基準になるかが確率的に選ばれていた。しかし現実状況では、どちら一方でも低い場合、リーダーは交替する。そこでこの部分のアルゴリズムを変更し、二つの利得の積を基準とするreplicator dynamicsを新たに開発した。さらに、リーダー支援行動の検証実験を行った。現実の社会的ジレンマが制裁を担うリーダーの存在によって解決されているならば、1)成員各人が直接非協力者を罰する状況と、2)リーダーが非協力者を罰しそのリーダーを成員が支援する状況では、成員の負担するコストが同じでも、2)の状況の方がコスト負担を厭わないことが予想される。この仮説を検証する実験室実験をおこなったところ、1)と2)の状況間で成員の平均コスト負担に有意な差は認められず、仮説は支持されなかった。この結果から、成員からリーダーへの支援を引き出すには、リーダーが制裁権限を担うだけでは不十分で、リーダー選出手続きの公正性や、リーダーの制裁行使意図の妥当性などが重要であることが示唆された。
著者
神 信人
出版者
日本社会心理学会
雑誌
社会心理学研究 (ISSN:09161503)
巻号頁・発行日
vol.12, no.3, pp.190-198, 1997-03-31 (Released:2016-12-06)
被引用文献数
2

The purpose of this study is to test a new hypothesis for the group identity effects in social dilemmas, the effect that common group membership promotes cooperation. According to the proposed hypothesis, people prefer to cooperate with ingroup members because they expect reciprocal responses from ingroup, but not from outgroup members. In other words, people are considered to expect generalized reciprocity to exist within groups but not beyond group boundaries. Based on this hypothesis, it was predicted that the previously observed group identity effect-subjects facing a prisoner's dilemma cooperate more with an ingroup member than with an outgroup member-exists only when the partner shares the membership information. When the partner does not know that the subject shares the same group membership, group identity effect is predicted not to emerge. Result of an experiment with 78 subjects clearly supported this prediction and rejected alternative hypotheses based on psychological distance(Krammer & Brewer, 1984), social identity (Billig & Tajfel, 1973), and ingroup stereotype (Brewer, 1978).
著者
神 信人 山岸 敏男
出版者
日本社会心理学会
雑誌
社会心理学研究 (ISSN:09161503)
巻号頁・発行日
vol.12, no.3, pp.190-198, 1997

The purpose of this study is to test a new hypothesis for the group identity effects in social dilemmas, the effect that common group membership promotes cooperation. According to the proposed hypothesis, people prefer to cooperate with ingroup members because they expect reciprocal responses from ingroup, but not from outgroup members. In other words, people are considered to expect generalized reciprocity to exist within groups but not beyond group boundaries. Based on this hypothesis, it was predicted that the previously observed group identity effect-subjects facing a prisoner's dilemma cooperate more with an ingroup member than with an outgroup member-exists only when the partner shares the membership information. When the partner does not know that the subject shares the same group membership, group identity effect is predicted not to emerge. Result of an experiment with 78 subjects clearly supported this prediction and rejected alternative hypotheses based on psychological distance(Krammer & Brewer, 1984), social identity (Billig & Tajfel, 1973), and ingroup stereotype (Brewer, 1978).
著者
松本 良恵 神 信人
出版者
日本グループ・ダイナミックス学会
雑誌
実験社会心理学研究 (ISSN:03877973)
巻号頁・発行日
vol.50, no.1, pp.15-27, 2010 (Released:2010-08-19)
参考文献数
36
被引用文献数
2 2

現実の社会では,社会的ジレンマはリーダーが非協力者を罰し,メンバーがそうしたリーダーを支援すると言う相互依存関係を通して解決されていると考えられる。この研究の目的は,進化ゲームシミュレーションを用いて,そうした相互依存関係がリーダーとメンバーの間に生まれる条件を明らかにすることにある。我々のシミュレーションでは,20の集団が設定されており,集団はそれぞれ20人のメンバーと1人のリーダーで構成されていた。リーダーは,自分の集団内の非協力者と,自分をサポートしない者を罰することができた。コンピュータ・シミュレーションの結果,ある条件が満たされる時に,非協力者とリーダーを支援しない者の両方を罰するリーダーが出現し,それにより多くのメンバーが協力とリーダーへの支援が強いられることで,社会的ジレンマは解決された。その条件とは,リーダーは個人的利益と集団利益の両方を高めないと,その地位を維持できないというものである。
著者
植村 友里 松本 良恵 神 信人
出版者
公益社団法人 日本心理学会
雑誌
心理学研究 (ISSN:00215236)
巻号頁・発行日
vol.85, no.2, pp.111-120, 2014 (Released:2014-06-25)
参考文献数
26

Why do people behave altruistically toward others, even in situations where nobody would observe their behavior? We formulated the following hypothesis regarding this question: “Reputations are decided by behaviors in situations that nobody can observe, rather than by behaviors in situations that can be observed by others.” The validity of this hypothesis was examined through a Prisoner’s Dilemma experiment. In the first stage, participants played the Prisoner’s Dilemma game in a situation where nobody could observe them. In the second stage, participants selected another partner in the game, based on information about their behavior in the first stage. The results indicated that participants tended to choose people that behaved altruistically in situations where nobody could observe them. Furthermore, this tendency was stronger with cooperative participants. These results support the hypothesis of this study.
著者
神 信人 山岸 俊男 清成 透子
出版者
公益社団法人 日本心理学会
雑誌
心理学研究 (ISSN:00215236)
巻号頁・発行日
vol.67, no.2, pp.77-85, 1996-06-26 (Released:2010-07-16)
参考文献数
20
被引用文献数
14 16

Two experiments examined the effect of illusion of control on ingroup favoritism found in the minimal group situation (Tajfel, Billig, Bundy, & Flament, 1971). In bilateral dependency condition, each member made allocation decisions for ingroup as well as outgroup participants. It was exactly the same situation used in the original studies under the minimal group paradigm, and the subjects knew that their reward allocation too depended on others' decisions. In contrast, in unilateral dependency condition, the subjects made allocation decisions knowing that theirs were not dependent on others' decisions. In Experiment 1, an ingroup bias in reward distribution was found in the bilateral dependency condition, but not in the unilateral condition. In Experiment 2, it was found that only those who felt illusion of control exhibited such an ingroup bias. Results of the experiments therefore confirmed that illusion of control explained ingroup favoritism, as Karp, Jin, Yamagishi, and Shinotsuka (1993) originally hypothesized.
著者
植村 友里 松本 良恵 神 信人
出版者
公益社団法人 日本心理学会
雑誌
心理学研究 (ISSN:00215236)
巻号頁・発行日
pp.85.12015, (Released:2014-06-01)
参考文献数
26

Why do people behave altruistically toward others, even in situations where nobody would observe their behavior? We formulated the following hypothesis regarding this question: “Reputations are decided by behaviors in situations that nobody can observe, rather than by behaviors in situations that can be observed by others.” The validity of this hypothesis was examined through a Prisoner’s Dilemma experiment. In the first stage, participants played the Prisoner’s Dilemma game in a situation where nobody could observe them. In the second stage, participants selected another partner in the game, based on information about their behavior in the first stage. The results indicated that participants tended to choose people that behaved altruistically in situations where nobody could observe them. Furthermore, this tendency was stronger with cooperative participants. These results support the hypothesis of this study.
著者
神 信人 田中 寿夫
出版者
公益社団法人 日本心理学会
雑誌
心理学研究 (ISSN:00215236)
巻号頁・発行日
vol.80, no.2, pp.123-130, 2009 (Released:2012-03-06)
参考文献数
19

When does a person who has been trusted reciprocate that trust? Kiyonari, Yamagishi, Cook, and Cheshire (2006) compared behavior in trust games and faith games and showed that in one-shot games, players who were trusted did not reciprocate that trust. In an experiment using trust games and dictator games, we examined what type of trust would elicit reciprocation of that trust by the trustee. In the experiment, information about the reason to trust the truster was manipulated to separate trust types into “trust attributable to the trustee” and “trust attributable to the truster.” We determined how much reciprocation was elicited by each of these types of trust. The results showed that trustees are more likely to reciprocate trust for “trust attributable to the trustee” than for “trust attributable to the truster.”
著者
山岸 俊男 結城 雅樹 神 信人 渡部 幹
出版者
北海道大学
雑誌
基盤研究(B)
巻号頁・発行日
2007

本研究の最大の成果は、自集団の成員を優遇する内集団ひいき現象を生みだす直接の心理機序が集団内部における自己の評判に対するセンシティビティーにあることを一連の最小条件集団実験を通して明らかにすることで、集団行動の進化的基盤に対する二つの説明原理である集団選択と間接互恵性の間の論争に対して、後者を支持する実証的知見を組織的に提供した点にある。
著者
植村 友里 松本 良恵 神 信人
出版者
公益社団法人 日本心理学会
雑誌
心理学研究 (ISSN:00215236)
巻号頁・発行日
vol.85, no.2, pp.111-120, 2014

Why do people behave altruistically toward others, even in situations where nobody would observe their behavior? We formulated the following hypothesis regarding this question: "Reputations are decided by behaviors in situations that nobody can observe, rather than by behaviors in situations that can be observed by others." The validity of this hypothesis was examined through a Prisoner's Dilemma experiment. In the first stage, participants played the Prisoner's Dilemma game in a situation where nobody could observe them. In the second stage, participants selected another partner in the game, based on information about their behavior in the first stage. The results indicated that participants tended to choose people that behaved altruistically in situations where nobody could observe them. Furthermore, this tendency was stronger with cooperative participants. These results support the hypothesis of this study.