A model is presented to account for the natural selection of what is termed reciprocally altruistic behavior. The model shows how selection can operate -against the cheater (non-reciprocator) in the system. Three instances of altruistic behavior are discussed, the evolution of which the model can explain: (1) behavior involved in cleaning symbioses; (2) warning cries in birds: and (3) human reciprocal altruism. Regarding human reciprocal altruism, it is shown that the details of the psychological system that regulates this altruism can (...) be explained by the model. Specifically, friendship,d islike, moralistic aggression, gratitude, sympathy, trust, suspicion, trustworthiness, aspects of guilt, and some forms of dishonesty and hypocrisy can be explained as important adaptations to regulate the altruistic system. Each individual human is seen as possessing altruistic and cheating tendencies, the expression of which is sensitive to developmental variables that were selected to set the tendencies at a balance appropriate to the local social and ecological environment. (shrink)

This is the first book to evaluate the significance and usefulness of the practices of anthropomorphism and anecdotalism for understanding animals.

The relationship between animal ownership and owners' health has received increasing attention in the recent human-companion animal literature. This article considers a new aspect of the human-companion animal relationship, that of compatibility between pet and owner. Compatibility is viewed as the fit between the animal and the owner on physical, behavioral, and psychological dimensions. A postal survey was used to test the hypothesis that compatibility has influences on physical and mental health that are independent of those due to owners' level (...) ofpet attachment and human social support. A sample group of 176 pet owners completed a questionnaire containing a new measure of compatibility as well as standard measures of pet attachment, human social support, and mental and physical health. Results of multiple regression analyses indicated that people who are relatively more compatible with their pets report better mental health overall and fewer physical symptoms. Social support was positively associated with mental health. Pet attachment was also positively associated with mental health, but negatively with physical health. (shrink)