Evolution of morality

The concept of the evolution of morality refers to the emergence of human moral behavior over the course of human evolution. Morality can be defined as a system of ideas about right and wrong conduct. In everyday life, morality is typically associated with human behavior rather than animal behavior. The emerging fields of evolutionary biology, and in particular evolutionary psychology, have argued that, despite the complexity of human social behaviors, the precursors of human morality can be traced to the behaviors of many other social animals. Sociobiological explanations of human behavior remain controversial. Social scientists have traditionally viewed morality as a construct, and thus as culturally relative, although others such as Sam Harris argue that there is an objective science of morality.

Social animals, from eusocial insects like ants to empathetic mammals like elephants, develop complex cooperative behaviors—often involving self-restraint, altruism, or even reproductive sacrifice—because group living dramatically increases their chances of survival and reproductive success. Primate sociality, particularly among chimpanzees and bonobos, reveals evolutionary roots of human morality through shared traits like empathy, reciprocity, and fairness, suggesting that moral behavior developed to promote cooperation and cohesion in increasingly complex social groups.

The social brain hypothesis suggests primates evolved larger brains primarily to handle complex social networks. Theory of mind enabled them to understand others’ mental states for navigating social interactions. Human altruism is seen as a unique, culturally influenced behavior shaped by both genetic and cultural evolution. Religion likely evolved by building on morality, introducing supernatural agents to encourage cooperation and restrain selfishness, which enhanced group survival. Additionally, emotions like disgust play a key evolutionary role in moral judgments by helping to avoid threats to health, reproduction, and social cohesion.