Cooperation is one of the defining characteristics of humans' success as a species. Cooperation allows two or more individuals to reach a goal that cannot be reached alone. Whereas the benefits of cooperation seem obvious, it can however, also come at a cost. Many cooperative acts are prone to free-riding and thus one needs proximate mechanisms to deal with such challenges. Studying such proximate mechanisms has recently taken off, yet most studies so far only concern primates. However, to study the evolution of such mechanisms, a broader spectrum of species will further illuminate our understanding of cooperation in animals, and through evolutionary homologous or convergent pathways, of cooperation in humans.
Therefore, I use a comparative approach and study cooperation in several bird and primate species. To test cooperation in these species I mainly use the loose-string paradigm (see picture), but I also aim to test different paradigms that require for example >2 collaborators.