The Evolution of Reciprocal Altruism (essay)

The evolution of reciprocal altruism explains how behaviors where animals help others—sometimes at a personal cost—can develop when there's a chance of receiving help in return. Originally, cooperation may have started randomly, but over time, individuals who helped those likely to return favors gained better survival and reproductive success. This creates a cycle where mutual aid benefits both parties, encouraging such behavior to spread. Essentially, reciprocal altruism is about building trust-based relationships that promote cooperation, helping species—including humans—thrive through mutually beneficial exchanges over generations.