This study examines the role of trust and reciprocity in the effectiveness of collective governance systems in hydrosocial territories, focusing on water associations managed by indigenous Aymara communities in the Bolivian Altiplano. Using path analysis and experimental economics, we measure the interaction between trust and reciprocity and cooperative behavior among 100 Aymara community members. Our results suggest that while trust is a critical factor in fostering cooperation, reciprocity is equally important in supporting the cooperation required for effective collective governance in hydrosocial territories. We find that reciprocity is particularly low in the associations studied. Our results show that the initial acts of trust were not reciprocated, making cooperation within the governance system difficult. Although communities exhibited prosocial behavior, this lack of reciprocity affected trust between members of different communities, leading to ineffective functioning of collective water resources management. More generally, our results show the vulnerability of collective governance in hydrosocial territories when collaboration is strongly based on negative reciprocal paradigms and increasingly dependent on extrinsic motivations. To address the internal causes of ineffective collective governance, a nuanced exploration of ways to foster intrinsic motivation and positive reciprocal interactions is needed and seems to require joint efforts by communities and political actors.
