The Erosion of Cooperative Networks and the Evolution of Social Hierarchies: A Comparative Approach

Evolutionary studies of cooperation have shown how socioecological context shapes the extent to which individuals help kin and non-kin. Pastoralists-people who make their living from herding livestock-traditionally rely on networks of cooperating households containing relatives and others. These herding groups provide examples of the independent emergence of similar social institutions for organizing cooperation, despite the ecological, geographic and political differences in different parts of the world. To shed light on how socioecological differences and commonalities affect these social institutions, we compared cooperative decision-making using gift games for 1,404 pastoralists across six sites in two countries (Saami areas in Norway and Tibetan areas in China). Members of the same herding group (called siida in Norway and ru skor in Tibet) received more gifts overall, regardless of kinship; gifts were preferentially given to poorer herders, especially in Tibet. Most variance in gift-giving occurred between study sites, due to differences in the effects of relatedness. Tibetan yak herders were most likely to give gifts to closer relatives belonging to other, geographically distant, herding groups. This pattern was not observed among Saami reindeer herders; instead, gifts went to close relatives within the same herding groups. Pastoralists cooperate with kin and non-kin within and between social groups in nuanced and complex ways, indicative of a multilevel structure resulting from this subsistence strategy. Our results form the first large-scale comparative study of social complexity in pastoralist cooperation, revealing the importance of social ties beyond the family and the centrality of herding groups as a general pattern for social organization among pastoralists.

1. Gjennom prosjektperioden har det blitt opparbeidet en kompetanse knyttet til forskning på samarbeid, både teoretisk og metodisk ved Framsenteret i Tromsø. 2. Dette prosjektet representerer et viktig steg for å belyse den rådende forståelsen av samarbeid som utelukkende har tatt utgangspunkt i jeger- og sankere. Litteraturstudier har vist at gjetergrupper er utbredt i stort sett hele verden og at det er en viktig link mellom hvordan landrettigheter er fordelt og samarbeid. Et komparativt perspektiv-som viser likheter og ulikheter på tvers av regioner og tilpasninger-vil gi oss bedre forståelse av samarbeid. 3. Forskning knyttet til samarbeid er viktig for å løse store samfunnsproblemer som klimaendringer, masseutryddelse og bærekraftig bruk av ressurser. Resultatene vil ha viktige forvaltningsimplikasjoner. Før forvaltningstiltak blir iverksatt burde det være obligatorisk for forvaltningen å evaluere effekten av lignende tiltak i andre regioner og land.

The main question of this research project is: how do changing land tenure policies affect cooperation and small-scale social systems? The appropriateness of transforming commons to private grazing has been contested, mainly because of its potential to exacerbate the problem it was introduced to counter, i.e. rangeland degradation. Previous studies have predominantly been based on single case studies and focused on the ecological consequences of land tenure changes alone. This project rectifies this shortcoming by embedding a systematic comparative analysis of the causes and consequences of privatisation in a comprehensive theoretical framework of cooperation and social change. This is achieved by comparing current land tenure changes in Norway and China and investigating its impact on nomadic pastoral social organisation. The cause of land tenure changes will be investigated by systematically reviewing the underlying policy with a specific focus on understanding how two different political systems result in the same policy implementation. The social consequences of privatisation will be investigated by recreating both historical and current cooperative networks, i.e. investigating the historical and present extent of the traditional siida system (Norway) and the ru skor system (China). The project will utilize different degrees of privatisation as quasi-natural experiments where experimental economic games will be performed to investigate the extent and possible transformation of cooperation, both within regions and between regions. Privatisation and land tenure changes may negatively impact individuals' ability to change groups. The ability for individuals to change groups is an important factor underlying the evolution of egalitarian social groups. By combining empirical data pertaining to the ability to change groups with modelling techniques (e.g. agent based modelling) the project aims to shed light whether groups have become or are becoming more hierarchical.