Abstract

This paper examines three ancient traits of religion whose origins likely date back to the Upper Paleolithic: ancestor worship, shamanism, and the belief in natural and animal spirits. Evidence for the emergence of these traits coincides with evidence for a dramatic advance in human social cooperation. It is argued that these traits played a role in the evolution of human cooperation through the mechanism of social scrutiny. Social scrutiny is an effective means of reducing individualism and enhancing prosocial behavior. Religion’s most ancient traits represent an extension of the human social world into the supernatural, thus reinforcing within-group cooperation by means of ever-vigilant spiritual monitors. Believing that the spirits were always watching may have helped reduce the number of non-cooperators within a group while reinforcing group behavioral norms, thus allowing humanlike levels of cooperation to emerge