  In human societies the probability of strategy adoption from a given person
may be affected by the personal features. Now we investigate how an
artificially imposed restricted ability to reproduce, overruling ones fitness,
affects an evolutionary process. For this purpose we employ the evolutionary
prisoner's dilemma game on different complex graphs. Reproduction restrictions
can have a facilitative effect on the evolution of cooperation that sets in
irrespective of particularities of the interaction network. Indeed, an
appropriate fraction of less fertile individuals may lead to full supremacy of
cooperators where otherwise defection would be widespread. By studying
cooperation levels within the group of individuals having full reproduction
capabilities, we reveal that the recent mechanism for the promotion of
cooperation is conceptually similar to the one reported previously for
scale-free networks. Our results suggest that the diversity in the reproduction
capability, related to inherently different attitudes of individuals, can
enforce the emergence of cooperative behavior among selfish competitors.
