What's in it for me? Self-regard precludes altruism and spite in chimpanzeesKeith Jensen
The Max Planck Institute for Evolutionary Anthropology, Department of Developmental and Comparative Psychology, Deutscher Platz 6, 04103 Leipzig, Germany
Proc Biol Sci 273:1013-21. 2006
..The main result across all studies was that chimpanzees made their choices based solely on personal gain, with no regard for the outcomes of a conspecific. These results raise questions about the origins of human cooperative behaviour...
Chimpanzees are vengeful but not spitefulKeith Jensen
Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, D 04103 Leipzig, Germany
Proc Natl Acad Sci U S A 104:13046-50. 2007
..Like humans, chimpanzees retaliate against personally harmful actions, but unlike humans, they are indifferent to simply personally disadvantageous outcomes and are therefore not spiteful...
Chimpanzees are rational maximizers in an ultimatum gameKeith Jensen
Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, D 04103, Leipzig, Germany
Science 318:107-9. 2007
..These results support the hypothesis that other-regarding preferences and aversion to inequitable outcomes, which play key roles in human social organization, distinguish us from our closest living relatives...
No third-party punishment in chimpanzeesKatrin Riedl
Department of Developmental and Comparative Psychology, Max Planck Institute for Evolutionary Anthropology, D 04103 Leipzig, Germany
Proc Natl Acad Sci U S A 109:14824-9. 2012
..Third-party punishment as a means of enforcing cooperation, as humans do, might therefore be a derived trait in the human lineage...
Chimpanzees help conspecifics obtain food and non-food itemsAlicia P Melis
Department of Comparative and Developmental Psychology, Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, 04103 Leipzig, Germany
Proc Biol Sci 278:1405-13. 2011
..Humans, however, show prosocial motives more readily and in a wider range of contexts...
Chimpanzees may recognize motives and goals, but may not reckon on themJosep Call
Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
Novartis Found Symp 278:56-65; discussion 65-70, 89-96, 216-21. 2007
..However, based on recent studies, it is not clear whether chimpanzees have any regard for others, calling into the question the point at which fairness and other-regard were used as building blocks for full-fledged human morality...