Presented by Antú Schamberger, Amanda Douglas, and Joel Schreiber Stevens, J. R. & Hauser, M. D. (2004). Why be nice? Psychological constraints on the evolution of cooperation. Cognitive Science, 8,

Video Altruism in Action!! Altruism in Action!!

Stevens, J. R. & Hauser, M. D. (2004). Why be nice? Psychological constraints on the evolution of cooperation. Cognitive Science, 8, Introduction Cooperation: joint action for a mutual benefit What are some reasons that humans tend to cooperate with each other? Selfish cooperation (mutualism): immediate benefits from the cooperation

Stevens, J. R. & Hauser, M. D. (2004). Why be nice? Psychological constraints on the evolution of cooperation. Cognitive Science, 8, Introduction continued… Altruistic interaction has to be costly for the cooperator and beneficial to the recipient Pure altruistic behavior might not seem selfish at first but is beneficial in the long run.

Stevens, J. R. & Hauser, M. D. (2004). Why be nice? Psychological constraints on the evolution of cooperation. Cognitive Science, 8, Continued… Reciprocal altruism: Reciprocal altruism: the exchange of donor and recipient roles in repeated altruistic interactions Three prerequisites to reciprocity: a large benefit to the recipient and a small cost to the donor a repeated opportunity for cooperative interactions to occur and the ability to detect cheaters

Stevens, J. R. & Hauser, M. D. (2004). Why be nice? Psychological constraints on the evolution of cooperation. Cognitive Science, 8, Detection and Punishment of Cheaters

Stevens, J. R. & Hauser, M. D. (2004). Why be nice? Psychological constraints on the evolution of cooperation. Cognitive Science, 8, Continued… In addition to the previous three there are other variables to reciprocity: time estimation, delayed gratification, detection and punishment of cheaters, analysis and recall of reputation These facets tend to use higher mental capabilities

Stevens, J. R. & Hauser, M. D. (2004). Why be nice? Psychological constraints on the evolution of cooperation. Cognitive Science, 8, Reciprocal altruism: theoretical and empirical evidence Axelrod and Hamilton Prisoner’s Dilemma: stable cooperation emerges from the continuous interactions between the players and that the first move of cooperation is then mimicked by the other players from there on out in an altruistic circle This theory extends to non- kin interactions in understanding why altruism might occur

Stevens, J. R. & Hauser, M. D. (2004). Why be nice? Psychological constraints on the evolution of cooperation. Cognitive Science, 8, Reciprocal altruism continued… Following experiments test this theory of reciprocity between non-kin Stephens and colleagues were they put blue jays into Prisoner’s Dilemma scenarios where pairs of birds had to peck certain keys to receive the rewards Hauser and colleagues used tamarin moneys to pull a tool to give food to non- kin without getting any food themselves

Stevens, J. R. & Hauser, M. D. (2004). Why be nice? Psychological constraints on the evolution of cooperation. Cognitive Science, 8, Cognitive constraints on cooperation Temporal Discounting: defined as a preference for smaller immediate rewards instead of bigger rewards that are delayed Numerical Discrimination: a number sense mechanism which consists of two parts. One is for numbers that are four or less and the second is for estimating big numbers. Learning/Memory: Pavlov, Memory decay and delay between altruistic acts

Stevens, J. R. & Hauser, M. D. (2004). Why be nice? Psychological constraints on the evolution of cooperation. Cognitive Science, 8, Conclusion Reciprocal altruism among non-kin is rare if not absent among animals compared to humans where it is prominent Further studies involving neurobiology can examine the cognitive module that humans use in reciprocity

Stevens, J. R. & Hauser, M. D. (2004). Why be nice? Psychological constraints on the evolution of cooperation. Cognitive Science, 8, Critical Review Interesting and informative: Little evidence of non-human animals reciprocating Little evidence of non-human animals reciprocating Blue Jays in experimental situations compared to in the wild Blue Jays in experimental situations compared to in the wild Prisoner’s Dilemna Prisoner’s Dilemna

Stevens, J. R. & Hauser, M. D. (2004). Why be nice? Psychological constraints on the evolution of cooperation. Cognitive Science, 8, Critical Review continued… Weak and Unclear cases: Vague description of the tool used for the Tamarin Monkeys experiment Vague description of the tool used for the Tamarin Monkeys experiment Few examples of experiments involving animals; external validity Few examples of experiments involving animals; external validity Conclusion did not seem sufficient to the article Conclusion did not seem sufficient to the article

Stevens, J. R. & Hauser, M. D. (2004). Why be nice? Psychological constraints on the evolution of cooperation. Cognitive Science, 8, Test Questions 1.What is selfish cooperation? a)Helping another and receiving benefits b)Immediate benefits from the cooperation c)Helping another and not receiving benefits 2.What are some reasons that humans tend to cooperate with each other? a)Foraging b)Bathing c)Learning 3.How many parts are there for number discrimination for animals? a)1 b)2 c)5

Stevens, J. R. & Hauser, M. D. (2004). Why be nice? Psychological constraints on the evolution of cooperation. Cognitive Science, 8, Test Questions 1.Are there only three prerequisites to reciprocity? T/F 2.Humans, rats, and squirrels are the only entities that have been studied for temporal discounting? T/F 3.Research found that it is rare to find non- kin reciprocity among animals? T/F