 Neither dictatorial nor extortionary strategies would seem likely to fare well in an evolutionary setting with larger populations. By definition, successful strategies become more commonplace in an evolutionary framework, and therefore more likely to face others like themselves. Because dictators and extortionists do not do well against themselves, any success they have in the evolutionary context will be self-limiting. Hilbe et al. confirm these intuitions. They show that when a very small population of general memory-one strategies is subject to mutation and evolution, the time that agents spend approximating ZD strategies is reasonably high compared the number of such strategies that are possible, the relative time spent approximating dictator strategies in particular is higher, and the relative time spent approximating extortionary strategies much higher still. As population size increases, however, the proportion of time spent approximating all three categories drops rapidly. When the population exceeds ten, time spent as exemplars of these strategies is virtually zero. At about the same population level, the average components \(x\) and \(z\) of the strategies \(\bS(x,y,z,w)\) of surviving agents (representing the odds of cooperating after receiving reward and punishment payoffs) rise rapidly while average components y and w decline slowly, so that in larger populations the average of the strategies looks like \(\bS(1, .9, .1, .1)\)—an imperfect version of \(\bP_1\). (As might be expected, as the average of strategies approaches \(\bP_1\), the average payoff increases and approaches the reward value. This suggests that in some circumstances the familiar idea that cooperation is more difficult among large groups than small ones gets matters exactly backwards.) 