Testing the Sexual and Social Benefits of Cooperation in Animals.

Theoretical models show that sexual and social selection can stabilise cooperation. However, field tests of these mechanisms have been difficult to conduct and the results are mixed. We discuss the conceptual and practical difficulties associated with testing the role of social and sexual selection on cooperation and argue that there are alternative ways of examining these hypotheses. Specifically, approaches based on the classic theories of sexual selection and signalling, and recent developments in the field of behavioural syndromes, provide mechanisms to insure the reliability of cooperation. In addition, methodological developments (social networks and microtracking) and long-term datasets, allow measuring partner choice in a cooperation context and the resulting fitness benefits for both the cooperators and the individuals that associate with them.