LAUSR

Pastoralists rely on networks of cooperating households containing relatives and others to help with production and various other daily activities. To understand how socioecological differences and commonalities affect different social networks, we compared cooperative decision-making using gift games for 755 people working in herding groups across six sites in two countries (Saami areas in Norway and Tibetan areas in China). We found that members of the same herding group received more gifts from each other. Most variance in gift-giving between study sites was due to differences in the effects of relatedness. Tibetan herders were more likely than Saami herders to give gifts to closer relatives belonging to geographically distant herding groups. Also, stated reasons of giving gifts were different in the two societies: kin and wealth (measured by herd size) were more important among Tibetan pastoralists, while reciprocity was more important among Saami. Social ties within and beyond the family as well as the centrality of herding groups within social networks are general patterns of social organization favoring cooperation among pastoralists.Significance statementPastoralists around the world have independently developed social institutions built around cooperative herding units, known as siidas in Norway and ru skor in China. Our study investigates how kin and non-kin, in the same herding group or belonging to other groups, are associated with cooperation. Our results show that communities in both countries exhibit similar social pattern in terms of who they chose to give gifts to, despite differences in socioeconomic status and culture. Most of the variance in cooperation occurred between sites, primarily due to the effect of kinship. Members of the same herding group were preferred recipients of gifts, regardless of kinship, although closer kin were more likely to receive gifts. The stated reasons for giving were different in the two sites: siidas prioritized reciprocity whereas ru skor preferred kin and less wealthy herders. We discuss that ecology should be taken into consideration in understanding social behaviors, even if under similar subsistence system.