Open Access. Powered by Scholars. Published by Universities.®

Biological Psychology Commons™

Open Access. Powered by Scholars. Published by Universities.®

Animal Studies

Institution
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 61 - 62 of 62

Full-Text Articles in Biological Psychology

The Selfish Nature Of Generosity: Harassment And Food Sharing In Primates, Jeffrey R. Stevens Jan 2004

The Selfish Nature Of Generosity: Harassment And Food Sharing In Primates, Jeffrey R. Stevens

Jeffrey Stevens Publications

Animals may share food to gain immediate or delayed fitness benefits. Previous studies of sharing have concentrated on delayed benefits such as reciprocity, trade and punishment. This study tests an alternative model (the harassment or sharing–under–pressure hypothesis) in which a food owner immediately benefits because sharing avoids costly harassment from a beggar. I present an experiment that varies the potential ability of the beggar to harass, and of the owner to defend the food, to examine the effects of harassment on food sharing in two primate species: chimpanzees (Pan troglodytes) and squirrel monkeys (Saimiri boliviensis). For …


Discounting And Reciprocity In An Iterated Prisoner’S Dilemma, David W. Stephens, Colleen M. Mclinn, Jeffrey R. Stevens Jan 2002

Discounting And Reciprocity In An Iterated Prisoner’S Dilemma, David W. Stephens, Colleen M. Mclinn, Jeffrey R. Stevens

Jeffrey Stevens Publications

The Iterated Prisoner’s Dilemma (IPD) is a central paradigm in the study of animal cooperation. According to the IPD framework, repeated play (repetition) and reciprocity combine to maintain a cooperative equilibrium. However, experimental studies with animals suggest that cooperative behavior in IPDs is unstable, and some have suggested that strong preferences for immediate benefits (that is, temporal discounting) might explain the fragility of cooperative equilibria. We studied the effects of discounting and strategic reciprocity on cooperation in captive blue jays. Our results demonstrate an interaction between discounting and reciprocity. Blue jays show high stable levels of cooperation in treatments with …