Briefly discuss the key points presented by Penner, Dovidio, Piliavin, and Shroeder (2005) in their article on prosocial behavior. Using the Trivers (1971) article for support, does pure altruism exist? Why or why not?

Penner, L. A., Dovidio, J. F., Piliavin, J. A., & Shroeder, D. A. (2005). Prosocial behavior: Multilevel perspectives. Annual Review of Psychology, 56, 365-392.

Trivers, R. L. (1971). The evolution of reciprocal altruism. The Quarterly Review of Biology, 46, 35-57.