How Learning Affects the Evolution of Strong Reciprocity. Adaptive Behaviour 14(3

Experiments show that humans cooperate with non-kin, including people they will never meet again, and punish non-cooperators at personal cost. This is called strong reciprocity. It has recently been sug-gested, based on evolutionary simulations of an agent-based model inspired by the ultimatum game, that strong reciprocity may arise from individual selection. Ontogenic adaptations were introduced to the model to see how phenotypic plasticity affects the evolution of strong reciprocity. The influence of plasticity is explored by varying the way in which agents adapt. Simulations show that plasticity during an agent’s lifetime changes the path of evolution toward interesting behaviors that better approach those observed in humans. As plasticity is increased, the average offers and acceptance threshold also increase. Keywords evolution of strong reciprocity · evolution of cooperation · ontogenic adaptations · learning · ultimatum game