Examination of utility of the prosocial behavior scale for evolutionary study of altruism

We examined usefulness of the prosocial behavior scale (Kikuchi, 1988) from a view of evolutionary cognitive science. Relationship between an actor and a recipient is important in evolutionary studies of altruistic behavior. The prosocial behavior scale is a ready-made scale for Japanese undergraduate students. However, this scale is not useful for evolutionary study of altruism because it includes items on helping behavior for family members, friends and strangers. From an evolutionary viewpoint, subjects of helping behavior should be separated according to kin relationship and social bonds. Therefore, we did a confirmatory factor analysis by classifying the items into groups that objects are strangers, friends and uncertain. Moreover, correlations between each of the former two groups and the amount of money the participants gave in a dictator game were examined. These results suggest usefulness of the prosocial behavior scale as a scale in evolutionary studies of human altruistic behavior