Cooperators

Cooperators are individuals, organizations, or species that engage in cooperative behavior—acting to increase the welfare of others or the group, sometimes at a personal cost. In biology, cooperation is widespread, from sterile worker ants to microbial mutualisms and parental care in mammals. Evolutionary explanations include kin selection, direct reciprocity, indirect reciprocity, and, in some models, group selection. In humans, cooperation underpins teamwork, institutions, and many economic arrangements; it can be voluntary (volunteer work, joint projects) or formal (cooperatives, public-private partnerships).

Game theory uses the term cooperator to describe an agent who chooses to cooperate in dilemmas such as the Prisoner’s Dilemma; defectors choose to defect. Repeated interaction and reputation can promote cooperation through reciprocity.

Cooperators may rely on norms, social sanctions, and institutions to sustain cooperative behavior, particularly in large groups. When costs of cooperation are too high or benefits poorly distributed, cooperation may decline, leading to freeriding or defection.

Cooperative behavior is studied across disciplines, including biology, economics, sociology, and political science. Related concepts include altruism, social capital, and collective action.