Abstract

This project investigates the mechanisms and functions of Triadic Post-Conflict Affiliation (TpcA), particularly appeasement, in wild geladas (Theropithecus gelada). Focusing on how bystanders interact with aggressors after conflict, this study explores whether such affiliative behaviors reduce stress, prevent further aggression, and support social cohesion. Conducted within the long-term “Geladas for Cooperation” research project in Debre Libanos, Ethiopia, it draws on a uniquely multi-level primate society to examine the emotional and evolutionary underpinnings of conflict resolution. Through systematic observation, behavioral coding, and social network analysis, the research will assess individual and contextual determinants of TpcA, as well as its motivational drivers. Complementary pilot work in captivity and contingency analysis of pre-existing data will ensure methodological robustness. By situating gelada behavior in a multispecies perspective, this study aims to deepen our understanding of sociality, morality, and cooperation—challenging rigid human/nonhuman boundaries and contributing to more ethical and informed primate research
practices.