Evolutionary modeling of human cooperative behavior

• Applicant: Professor Dr. Dirk Semmann
• Subject Area: Social Psychology, Industrial and Organisational Psychology
• Term: from 2005 to 2008
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 13840408

Since Darwin formulated his theory of natural selection, biologists have attempted to explain the evolutionary emergence of cooperation between unrelated individuals. Why selfish individuals act cooperatively towards non relatives at a personal cost remains unresolved. The project aims to determine novel circumstances that promote cooperation in indirect reciprocity and public goods situations. It is often difficult to relate empirical findings to the results of existing models. I will use ideas derived from my empirical experience, to develop new agent based, evolutionary computer models. Image scoring and standing are two different approaches as to how a reputation is built in indirect reciprocity models. The main distinction between the two is that standing differentiates between justified and unjustified defections. The importance for humans to be able to differentiate between justified and unjustified defections can not be explained satisfactorily. The theoretical models favor the standing mechanism, but the empirical data matches the image scoring far more accurately. The reason for this discrepancy may lie in the artificial binary scale of the standing strategy, whereby individuals can only be either good or bad, in contrast to the continuous scale of image scoring. In the new model, I will eliminate the scale differences between standing and image scoring, in order to test the impact of justification in cooperative behavior. Secondly, spatial population structure has been shown to promote cooperation. In current models, individuals can solely interact with their direct neighbors, whereas in more natural situations, humans are able to interact with direct and indirect neighbors. In the new approach individuals will be able to interact with indirect neighbors and they will be able to refuse to interact with unreliable partners, rather forming bonds with cooperative individuals.

• DFG Programme: Research Fellowships
• International Connection: Austria
• Host: Professor Dr. Harald Rindler