We investigate experimentally the underlying motivations and individual differences with regard to the participation in between-group conflict in nested social dilemmas. In our nested social dilemmas, the collective is divided into two groups, and individuals allocate tokens between a private, a...

Taking note of the wide variety and growing list of models in the literature to explain patterns of behavior observed in laboratory experiments, this paper identifies two tests, the Variety Test (ability of a model to explain outcomes under variety or alternative scenarios) and the Psychological...