This paper presents a formal theory of reciprocity. Reciprocity means that people reward kind actions and punish unkind ones. The theory takes into account that people evaluate the kindness of an action not only by its consequences but also by the intention underlying this action. The theory...

Repeated interactions provide a prominent but paradoxical hypothesis for human cooperation in one-shot interactions. Intergroup competitions provide a different hypothesis that is intuitively appealing but heterodox. We show that neither mechanism reliably supports the evolution of cooperation...

We explain contributions in public goods games with the help of the reciprocity model of Dufwenberg and Kirchsteiger (2004) by applying some plausible modifications: Most importantly, we assume that subjects overestimate the kindness of their group members. In combination with the finding that...

Why do people engage in costly cooperation with unknown others that they will never meet again? Answers to this evolutionary puzzle emphasize the role of indirect reciprocity (i.e., cooperation through reputation), whereby cooperation is not reciprocated by the recipient but by other members of...

This chapter presents some insights from basic behavioural research on the role of human pro-social motivation to maintain social order. I argue that social order can be conceptualised as a public good game. Past attempts to explain social order typically relied on the assumption of selfish and...

This chapter presents some insights from basic behavioural research on the role of human pro-social motivation to maintain social order. I argue that social order can be conceptualized as a public good game. Past attempts to explain social order typically relied on the assumption of selfish and...

Explaining human cooperation in large groups of non-kin is a major challenge to both rational choice theory and the theory of evolution. Recent research suggests that group cooperation can be explained by positing that cooperators can punish non-cooperators or cheaters. The experimental evidence...