The distinction between domain specificity and domain generality is widespread in cognitive science. Yet, the difference between the two types of cognitive capacities has rarely been made in a principled manner. Moreover, some of the examples that are put forward to illustrate it in the literature are either spurious or misleading. In this paper, I use a number of examples to determine what domain specificity is, and just as importantly, what it is not. A domain-specific cognitive system is one that is in principle generalizable, but which the cognizer does not extend to cases that the system did not originally evolve to deal with.