Sapolsky (1990, 2005)
Robert Sapolsky has studied baboon troops in Kenya for over 30 years. His research has contributed to our understanding of stress and health. The following summary is a summary of two studies; first, in his study of 1990, he discusses findings of cortisol levels in baboon hierarchies. Secondly, there is a paper in 2005 in which he outlines the health effects seen in baboons at the bottom of the hierarchy.