NAKANISHI Daisuke    Department   Hiroshima shudo University  The Faculty of Health Sciences    Position   Professor
Date	2017/07/04
Presentation Theme	Ingroup favouritism in Japanese baseball fans
Conference	The European Conference on Psychology & the Behavioral Sciences
Conference Type	International
Presentation Type	Poster
Contribution Type	Collaborative
Venue	Brighton, UK
Publisher and common publisher	Nakagawa, Y., Yokota, K., & Nakanishi, D.
Details	In this study, we compared the ability of Social Identity Theory (SIT) and Bounded Generalized Reciprocity Hypothesis (BGR) to explain ingroup favoritism in real social groups. We conducted In thisthe vignette experiments , wethat adapted Japanese baseball fans as a target group, and conducted the experiment that designed as controlling various confounded factors to possibly influence ingroup favoritism in Japanese baseball fans. In this experiment, We we manipulated run a vignette experiment in which expectation of reciprocity, which is was assumed as a precursor of ingroup favoritism by BGR, by controlling knowledge of group membership was manipulated. In Study 1 (Nakagawa, Yokota, & Nakanishi, 2015), participants were 117 undergraduate students who were fans of one Japanese baseball team were participated in an experiment that ingroup cooperation (helping behavior) and expectations of ingroup members’ cooperation were measured in four scenarios. The results thus further verified the theoretical validity of SIT and BGR in real social groups. In Study 2 addressed the limitations in Study 1, lack of cost of cooperation and limited the samples tlimited to undergraduates, by requiring a cost for cooperation, and employing a large sample (N=1635) of adult baseball team fans. Contents of some cost were added to ingroup cooperationHelping behavior and expectations of cooperation of other group members were measured in four scenarios follow Study 1, but add contents of some cost when the participants cooperate others, and . In each scenario, the expectation of reciprocity was also manipulated as Study 1. The results of Study 2 supported BGR by showing in-group cooperation only when they could expect reciprocity. It is concluded that cost of ingroup cooperation can enhanced the psychological process of BGR, while ingroup cooperation without cost proceeds both processes of SIT and BGR.