2014 年 12 巻 2 号 p. 113-117
In the present research, we examined the effects of belief in free will on interpersonal aggression. Baumeister et al. (2009) demonstrated disbelief in free will promoted aggression toward an innocent target. However, our aggressive behavior is not limited to such non-retributive aggression. For instance, people often attack a person who has shown aggression against them in order to defend themselves or take sanctions. The strength of such aggressive behavior is proportional to perceived responsibility of the transgressor (Ohbuchi, 1987). It has been shown that belief in free will has strong relation to the attribution of responsibility and punishment. Thus, we predicted belief in free will would promote aggression against a transgressor. Forty-five undergraduates participated in the study and they were randomly assigned to one of the three conditions (free will, determinism, or control). After free will manipulation, participants conducted the competitive reaction time game against a fictitious participant. In the task, participants and a hypothetical opponent repeatedly delivered the blast of white noise to each other. The intensity of the blast of white noise specified by participants was the measure of aggression. The results indicated believing in free will increased aggression among participants high in trait aggression. The finding raise the possibility that belief in free will of self and that of others differently influence aggressive behavior.