This paper presents a "second generation" theory on the nature of social preferences. Incorporating an inter-temporal ingredient, we generate an outcome-based model which focuses on the conflict between cooperation towards social efficiency and competition for the individual relative standing....

Understanding the proximate and ultimate sources of human cooperation is a fundamental issue in all behavioural sciences. In this article we review the experimental evidence on how people solve cooperation problems. Existing studies show without doubt that direct and indirect reciprocity are...