There is continuing debate about what explains cooperation and self-sacrifice in nature and in particular in humans. This paper suggests a new way to think about this famous problem. I argue that, for an evolutionary biologist as well as a quantitative social scientist, the triangle of two...

In evolutionary models of indirect reciprocity, reputation mechanisms can stabilize cooperation even in severe cooperation problems like the prisoner's dilemma. Under certain circumstances, conditionally cooperative strategies, which cooperate iff their partner has a good reputation, cannot be...

Classical economic theory assumes that people are rational and selfish, but behavioral experiments often point to inconsistent behavior, typically attributed to "other regarding preferences." The Ultimatum Game, used to study fairness, and the Trust Game, used to study trust and trustworthiness,...

Cooperation in repeated public goods game is hardly achieved, unless contingent behavior is present. Surely, if mechanisms promoting positive assortment between cooperators are present, then cooperators may beat defectors, because cooperators would collect greater payoffs. In the context of...

In this paper, we analyze how kinship among family members affects intergenerational cooperation in a public good game. 165 individuals from 55 families, comprising three generations (youths, parents, and grandparents), play a public good game in three different treatments: one in which three...

We study the coevolution of cooperation, preferences, and cooperative signals in an environment where individuals engage in a signaling-extended prisoner's dilemma. We prove the existence of a cooperative equilibrium constituted by a (set of) limit cycle(s) and stabilized by the dynamic...

Network reciprocity has been successfully put forward (since M. A. Nowak and R. May's, 1992, influential paper) as the simplest mechanism-requiring no strategical complexity-supporting the evolution of cooperation in biological and socioeconomic systems. The mechanism is actually the network,...