Human coalitions frequently persist through multiple, overlapping membership generations, requiring new members to cooperate and coordinate with veteran members. Does the mind contain psychological adaptations for interacting within these intergenerational coalitions? In this paper, we examine whether the mind spontaneously treats newcomers as a motivationally privileged category. Newcomers—though capable of benefiting coalitions—may also impose considerable costs (e.g., they may free ride on other members, they may be poor at completing group tasks). In three experiments we show (1) that the mind (...) categorizes coalition members by tenure, including newcomers; (2) that tenure categorization persists in the presence of orthogonal and salient social dimensions; and (3) that newcomers elicit a pattern of impressions consistent with their probable ancestral costs. These results provide preliminary evidence for a specialized component of human coalitional psychology: an evolved concept of newcomer. (shrink)

Boyer & Petersen lay out a compelling theory for folk-economic beliefs, focusing on beliefs about markets. However, societies also allocate resources through mechanisms involving power and group decision-making, through the political economy. We encourage future work to keep folkpoliticaleconomic beliefs in mind, and sketch an example involving pollution and climate change mitigation policy.

Pietraszewski exemplifies the need for computational theory using group conflict; I complement this with an example of group cooperation. He criticizes past theories for having black boxes; I suggest his theory also has a black box – the concept of costs. He divides what mentally constitutes a group from mere ancillary attributes; I hazard that some of these attributes are essential.