Original Article An eye-like painting enhances the expectation of a good reputation ☆ Ryo Oda a, ⁎ , Yuki Niwa a , Atsushi Honma b , Kai Hiraishi c a Graduate School of Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466-8555, Japan b Department of Evolutionary Studies of Biosystems, The Graduate University for Advanced Studies, Shonan Village, Kanagawa 240-0193, Japan c Kokoro Research Center, Kyoto University, Kyoto 606-8501, Japan Initial receipt 10 July 2010; final revision received 15 November 2010 Abstract The presence of subtle cues of being watched has been reported to make people behave altruistically, even when they are anonymous. Individual selection theory predicts that generosity in the presence of eyes is based on the providers' expectation of a future reward. On the other hand, as we are living in quite a large society in which altruistic punishment is effective, the eyes could elicit fear of punishment. However, no previous study has investigated whether people are concerned with their reputation when subtle social cues are present. We conducted the dictator game in the presence of, or without, a painting of stylized eyes. The participants were then asked to complete a post- experimental questionnaire designed to investigate what they were thinking when they decided the amount of money to offer the recipient and how they perceived the experimental situation. Participants in the eye condition allocated more money to the recipient than did those in the control condition. This effect was not mediated by fear of punishment but by the expectation of a reward. Moreover, the results suggested that the participants expected their actions would enhance their reputation in the eyes of a third party. © 2011 Elsevier Inc. All rights reserved. Keywords: Altruism; Dictator game; Generosity; Reputation; Reciprocity 1. Introduction People show altruistic behaviors toward strangers with whom they have no committed relationship. Two explanations have been proposed for this kind of altruism. One explanation rests on the perspective of individual selection. Indirect- reciprocity and competitive-altruism theories propose that actors benefit in the long-term by “purchasing” increased cooperation from others when they “pay” for altruistic behavior. That is, altruistic behavior is a form of investment (Bshary & Bergmuller, 2008). The other explanation, strong reciprocity theory, argues that people “tend to behave prosocially and punish antisocial behavior at cost to themselves even when the probability of future interactions is low or zero” (Gintis, 2000). This theory proposes that altruism has evolved on the basis of group selection. Theoretical studies indicate that building a good reputation plays an important role in the evolution of reciprocal altruism through indirect reciprocity (e.g., Nowak & Sigmund, 1998). Even if an altruist is not directly rewarded by the recipient, information about his or her past behavior can be used by potential partners in making decisions about interactions. Results from laboratory experiments support this model. People are willing to cooperate when they know their behavior is being observed by others. Furthermore, people use reputation to choose their partners (Barclay, 2004; Milinski, Semmann & Krambeck, 2002a, 2002b; Wedekind & Braithwaite, 2002). A reputation of generosity leads to stable cooperation in large groups. According to the strong reciprocity model, on the other hand, humans have evolved an inclination to punish people who violate the norm of cooperation through group selection (Fehr & Fischbacher, 2003; Fehr & Gachter, 2002; Gintis, Bowles, Boyd & Fehr, 2003). Boyd, Gintis, Bowles and Richerson (2003) argued that this altruistic punishment is important to maintain cooperation in quite a large group because the payoff disadvantage of altruistic cooperators relative to defectors is independent of the frequency of defectors in the group, while the cost disadvan- tage of those engaged in altruistic punishment declines as Evolution and Human Behavior 32 (2011) 166 – 171 ☆ This study was supported by Kokoro Research Center Joint Program, Kyoto University. ⁎ Corresponding author. Graduate School of Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466-8555, Japan. Tel.: +81 52 735 5112; fax: +81 52 735 5112. E-mail address: oda.ryo@nitech.ac.jp (R. Oda). 1090-5138/$ – see front matter © 2011 Elsevier Inc. All rights reserved. doi:10.1016/j.evolhumbehav.2010.11.002