Evolution of Behavior in Family Games
by
Ted Bergstrom
Economics Dept, University of California Santa Barbara

In 1964, the great evolutionary biologist, William Hamilton proposed that evolutionary selection would result in a population of individuals in which each acts to maximize its inclusive fitness, which Hamilton defined as a weighted average of its own survival probability and the survival probabilities of its kin, with the weights applied to relatives being proportional to their degree of relationship.

Hamilton's papers were written almost 10 years before G. R. Price and John Maynard Smith introduced game theory to biologists. It is therefore not surprising that he did not model familial interactions as a game. The kind of interactions that Hamilton studied belong to a special class of games in which the effects of actions are additive. Many economic interactions between relatives lack this additive structure and it turns out for such interactions, Hamilton's rule does not in general apply. This paper introduces a more general principle that applies to a broad class of games and explains the relation between this principle and Hamilton's rule.

Ted Bergstrom's papers on evolution

Date received: June 19, 2000

Copyright © 2000 by the author(s). The author(s) of this document and the organizers of the conference have granted their consent to include this abstract in Atlas Conferences Inc. Document # cafk-07.