Cooperation through indirect reciprocity: image scoring or standing strategy?

@article{citeulike:1261102, abstract = {Theorists have only recently shown that cooperation through indirect reciprocity can evolve. The first modelling approach favoured a mechanism called image scoring. Helping someone increases one's image score, whereas refusing to help reduces it. The evolutionary outcome was a discriminator image scoring strategy that helps everybody who has, for example, a positive image score. Two experimental studies with humans found results that were compatible with discriminator image scoring. However, a new analysis of other theorists, based on another population structure, has cast doubts on the evolutionary stability of strategies using the recipient's score as a sole basis for decision. The new theoretical study confirmed that a strategy aiming at "good standing" has superior properties and easily beats image scoring. An individual loses good standing by failing to help a recipient in good standing, whereas failing to help recipients who lack good standing does not damage the standing of a potential donor (but would reduce his image score). The present empirical study with 23 groups of seven human subjects each was designed for distinguishing between the two proposed mechanisms experimentally. The results differed strongly from standing strategies, which might demand too much working memory capacity, but were compatible with image scoring or a similar strategy to a large extent. Furthermore, donors of constant "NO players" compensated for their refusing to help these players by being more generous to others.}, address = {Department of Evolutionary Ecology, Max-Planck-Institute for Limnology, 24306 Pl\"{o}n, Germany. milinski@mpil-ploen.mpg.de}, author = {Milinski, M. and Semmann, D. and Bakker, T. C. and Krambeck, H. J. }, citeulike-article-id = {1261102}, doi = {http://dx.doi.org/10.1098/rspb.2001.1809}, issn = {0962-8452}, journal = {Proc Biol Sci}, keywords = {cooperation, evolution, image, model, standing}, month = {December}, number = {1484}, pages = {2495--2501}, posted-at = {2007-04-27 20:43:14}, priority = {2}, title = {Cooperation through indirect reciprocity: image scoring or standing strategy?}, url = {http://dx.doi.org/10.1098/rspb.2001.1809}, volume = {268}, year = {2001} }

TY - JOUR ID - citeulike:1261102 L3 - citeulike-article-id:1261102 TI - Cooperation through indirect reciprocity: image scoring or standing strategy? JF - Proc Biol Sci VL - 268 IS - 1484 SP - 2495 EP - 2501 AD - Department of Evolutionary Ecology, Max-Planck-Institute for Limnology, 24306 Plön, Germany. milinski@mpil-ploen.mpg.de SN - 0962-8452 N2 - Theorists have only recently shown that cooperation through indirect reciprocity can evolve. The first modelling approach favoured a mechanism called image scoring. Helping someone increases one's image score, whereas refusing to help reduces it. The evolutionary outcome was a discriminator image scoring strategy that helps everybody who has, for example, a positive image score. Two experimental studies with humans found results that were compatible with discriminator image scoring. However, a new analysis of other theorists, based on another population structure, has cast doubts on the evolutionary stability of strategies using the recipient's score as a sole basis for decision. The new theoretical study confirmed that a strategy aiming at "good standing" has superior properties and easily beats image scoring. An individual loses good standing by failing to help a recipient in good standing, whereas failing to help recipients who lack good standing does not damage the standing of a potential donor (but would reduce his image score). The present empirical study with 23 groups of seven human subjects each was designed for distinguishing between the two proposed mechanisms experimentally. The results differed strongly from standing strategies, which might demand too much working memory capacity, but were compatible with image scoring or a similar strategy to a large extent. Furthermore, donors of constant "NO players" compensated for their refusing to help these players by being more generous to others. KW - cooperation KW - evolution KW - image KW - model KW - standing AU - Milinski, M AU - Semmann, D AU - Bakker, TC AU - Krambeck, HJ PY - 2001/12/07/ UR - http://dx.doi.org/10.1098/rspb.2001.1809 ER -