How do firms adapt? In recent years, this old question has been given new answers—albeit partial ones. On the one hand, cognition scholars have emphasized managerial attention to environmental change as a key driver of adaptation. On the other hand, dynamic capabilities scholars have underscored the role of asset reconfigurations implemented amidst shifting environments. However, the explanatory powers of the two perspectives have not yet been assessed comparatively. We use fuzzy-set analyses of U.S. defense firms' responses to 9/11 to model the two perspectives as potentially competing or complementary, but our findings suggest that neither dynamic capabilities nor superior cognition must be present for firms to adapt. Instead, we identify four types of adapters (anticipative, responsive, opportunistic, and decisive), as well as the possibility of strategic non-adaptation. These results lead us to reassess the cognition and capabilities literatures and to outline a new, integrative framework to explain adaptation.