This paper discusses Stanovich's appeal to individual differences in reasoning and decision-making to undermine the “adaptive rationality” project put forth by Gigerenzer and his co-workers. I discuss two different arguments based on Stanovich's research. First, heterogeneity in the use of heuristics seems to be at odds with the adaptationist background of the project. Second, the existence of correlations between cognitive ability and susceptibility to cognitive bias suggests that the “standard picture of rationality” (Stein, 1996, 4) is normatively adequate. I argue (...) that, as matters stand, none of the arguments can be seen as fully compelling. Nevertheless, my discussion is not only critical of Stanovich's research, as I also show that (and how) his research can push forward the so-called “rationality debate” by encouraging greater theoretical and experimental work. (shrink)