ce. Proc. Royal Soc. Lond. B, 258, 133-140. [15] Boyd, R., Richerson, P.J., 2005. Solving the Puzzle of Human Cooperation. In: Levin- son, S. (Ed.), Evolution and Culture. MIT Press, Cambridge, MA, pp. 105132. [16] Bshary, R., Grater, A., Willener, A., Leimar, O., 2008. Pairs of cooperating cleaner fish provide bette