EN
It is often claimed that structured collections of individuals with mental or cognitive states-such collections as courts, countries, and corporations-have mental or cognitive states of their own. The existing critical literature casts substantial doubt on this claim. In this paper, I evaluate a defensive move made by some proponents of the view that groups have mental or cognitive states of their own: to concede that group states and individual states aren’t of the same specific natural kinds, while holding that groups instantiate different species of mental or cognitive states-perhaps a different species of cognition itself-from those instantiated by humans. In order to evaluate this defense of group cognition, I present a view of natural kinds-or at least of the sort of evidence that supports inferences to sameness of natural kind-a view I have previously dubbed the ‘tweak-and-extend’ theory, as well as a theory of cognitive systems. Guided by the tweak-and-extend approach, I arrive at a tentative conclusion: that what is common to models of individual cognitive processing and models of group processing does not suffice to establish sameness of cognitive (or mental) kinds, properties, or state-types across individuals and extant groups, not even at a generic level.