Social relations and their health impact in tree shrews.

In the wild, tree shrews (Tupaia belangeri) live in pairs in territories which they defend vigorously against strange conspecifics. The paper gives an overview on some of our laboratory studies with tree shrews, which demonstrate the great relevance the concepts of Jim Henry have in understanding the biological relevance of mammalian social behavior. A basic result of these studies is that the physiological consequences of social relations between mammals depend on the appraisal of the situation by the animals and their coping behavior. Appraisal of a stimulus or a situation, as well as the resulting coping behavior, are basically psychological processes. There are, therefore, no simple relationships between stimuli imposed on individuals and their physiological responses; rather the behavioral, psychological and, thus, the physiological responses of individuals to stimuli differ depending on their genetics, prenatal influences and postnatal learning processes. This means, to understand the consequences of social relations between individuals, an integrated approach is required to assess which factors, including social rank and bonds to conspecifics, interact to affect an individual's fertility and health, as has been so clearly demonstrated in the work of Jim Henry.