Mechanism (biology)

Philosophy

Biology

Punishment (psychology)

Group selection

Inclusive fitness

Microeconomics

Social psychology

Selection (genetic algorithm)

Economics

Creatures

Computer science

Anthropology

Paleontology

Psychology

Repeated game

Altruism (biology)

Reputation

Epistemology

Reciprocal altruism

Natural (archaeology)

Sociology

Artificial intelligence

Prosocial behavior

Kin selection

Game theory

Strong reciprocity

Social science

Nature

Human cooperation is an evolutionary puzzle. Unlike other creatures, people frequently cooperate with genetically unrelated strangers, often in large groups, with people they will never meet again, and when reputation gains are small or absent. These patterns of cooperation cannot be explained by the nepotistic motives associated with the evolutionary theory of kin selection and the selfish motives associated with signalling theory or the theory of reciprocal altruism. Here we show experimentally that the altruistic punishment of defectors is a key motive for the explanation of cooperation. Altruistic punishment means that individuals punish, although the punishment is costly for them and yields no material gain. We show that cooperation flourishes if altruistic punishment is possible, and breaks down if it is ruled out. The evidence indicates that negative emotions towards defectors are the proximate mechanism behind altruistic punishment. These results suggest that future study of the evolution of human cooperation should include a strong focus on explaining altruistic punishment.

Altruistic punishment in humans