Experimental games model situations in which the future outcomes of individuals and groups depend on their own choices and on those of other (groups of) individuals. Games are a powerful tool to identify the neural and psychological mechanisms underlying interpersonal and group cooperation and...

Prior studies of the effect of group identification on cooperation in social dilemmas have advanced two competing accounts of this effect, the goal-transformation hypothesis, which holds that identification implies a sense of collective self, which makes personal and collective goals...