Suppose a strategy for learning the optimal behavior in repeatedly pla
yed games is genetically determined. Then the animal is engaged in a l
earning game as well as the repeatedly played game. Harley (1981, J. t
heor. Biol. 89, 611-633) considers evolutionarily stable strategies in
such learning games, called evolutionarily stable (ES) learning rules
. Harley's work, though significant, is limited in that he does not es
tablish the stochastic convergence of ES learning rules. Furthermore,
his study of the relative payoff sum (RPS) approximation is limited to
simulation experiments. Here, the stochastic convergence of ES learni
ng rules and the RPS approximation is established. The ES learning rul
es and the RPS approximation were found to converge to the same qualit
y, the so-called matching ratio, with probability one. (C) 1995 Academ
ic Press Limited