Relationship Value, Emotion, and Uncertainty Shape Conflict-Resolution Communication in a Wild Primate.

Studying how nonhuman primates tailor signals and behavioral patterns to resolve ingroup conflicts provides insight into the evolution of communicative and behavioral complexity in conflict management. Here, we explore how, in wild geladas, primates with a uniquely rich vocal-visual repertoire, aggressors and victims take into account relationship value, perceived risk and uncertainty, emotional dynamics, and audience and external factors when producing nonaggressive signals after conflicts. We found that reconciliation in the study groups occurred rapidly, was mainly initiated by aggressors, and was mediated by post-conflict sequences composed of vocalizations, sometimes supplemented with visual signals and tactile patterns. The complexity of post-conflict sequences-indexed by their length, sensory channels, and signal types-was amplified in aggressor-victim dyads with stronger social bonds, following more intense victim distress signals, with dominant aggressors, and between genetically unrelated individuals. These patterns reflect sensitivity to uncertainty, relationship quality, emotional states, and to the external audience. Such behavioral flexibility helps individuals navigate the challenges of complex social life, where multiple relationships must be continuously tracked, thereby supporting social competence and group cohesion. Post-conflict signaling lies at the intersection of social and cognitive sophistication, revealing evolutionary links to human complex communication.