Cultural and contextual variation in first mover norms of ownership: evidence from an Achuar community

The proposal that humans possess an evolved psychology of ownership is a highly plausible one. But what, if any, features of human ownership psychology might be universal? Psychologists have proposed that human ownership psychology might contain rules or norms for determining ownership, some of which might be universal. Here we explore first mover norms, in which an individual who acts first or exerts higher initial effort towards an object is recognized as its owner. Developmental studies in North America and Europe have provided evidence that first mover intuitions, especially about first possession, reliably develop in childhood, and some cross-cultural studies have supported this. Ethnographic research, however, provides mixed evidence about the universality of first-mover norms across cultures and domains. Here we report results from an experimental study comparing judgments of Achuar adults in Ecuador with those of an online U.S. sample. Achuar judgments leaned weakly in favor of first possessors in the domain of hunted game, but not for land. For land, a principle of use took precedence over first possession. U.S. participants, on the other hand, exhibited strong first possessor intuitions across both domains, consistent with prior results in the psychological literature. Together these findings suggest that first mover norms for assigning ownership may be more culturally and contextually variable than prior psychological research has suggested.