Title

Preferential partner selection in an evolutionary study of Prisoner's Dilemma

Campus Units

Economics, Mathematics

Document Type

Article

Publication Version

Submitted Manuscript

Publication Date

1996

Journal or Book Title

Biosystems

Volume

37

Issue

1-2

First Page or Article ID Number

99

Last Page

125

DOI

10.1016/0303-2647(95)01548-5

Abstract

Partner selection is an important process in many social interactions, permitting individuals to decrease the risks associated with cooperation. In large populations, defectors may escape punishment by roving from partner to partner, but defectors in smaller populations risk social isolation. We investigate these possibilities for an evolutionary Prisoner's Dilemma in which agents use expected payoffs to choose and refuse partners. In comparison to random or round-robin partner matching, we find that the average payoffs attained with preferential partner selection tend to be more narrowly confined to a few isolated payoff regions. Most ecologies evolve to essentially full cooperative behavior, but when agents are intolerant of defections, or when the costs of refusal and social isolation are small, we also see the emergence of wallflower ecologies in which all agents are socially isolated. Between these two extremes, we see the emergence of ecologies whose agents tend to engage in a small number of defections followed by cooperation thereafter. The latter ecologies exhibit a plethora of interesting social interaction patterns.

Comments

This is a working paper of an article from Biosystems 37 (1996): 99, doi:10.1016/0303-2647(95)01548-5.