The evolution of cooperation in a system of agents playing the iterated prisoner's dilemma (IPD) is investigated. We present results for the standard two-person IPD as well as the more general N-person IPD (NIPD) game. In our computational model, agents can recognize each other and decide whether to interact or not, based upon ``tags'' (labels). We consider the evolutionary stability of the evolving populations. Previous work is extended by introducing sexual reproduction (recombination) of agents and by analyzing its influence on the evolving populations. We observed the occasional formation of very stable cooperative societies, as opposed to previous results without sexual reproduction. These cooperative societies are able to resist invasions of ``mimics''(defecting agents with the tag of a cooperating agent).

Learning (acm I.2.6), Distributed Artificial Intelligence (acm I.2.11), SOCIAL AND BEHAVIORAL SCIENCES (acm J.4)
Learning and adaptive systems (msc 68T05), 2-person games (msc 91A05), unknown (msc 91A06), Signaling, communication (msc 91A28)
Software (theme 1), Logistics (theme 3), Energy (theme 4)
CWI
Software Engineering [SEN]
Intelligent and autonomous systems

Alkemade, F, van Bragt, D.D.B, & La Poutré, J.A. (2000). Stabilization of tag-mediated interaction by sexual reproduction in an evolutionary agent system. Software Engineering [SEN]. CWI.