Three studies of dominance explore the frequency concept of disposition, which entails categories of acts that are topographically dissimilar but nonetheless considered to be manifestations of a common disposition. In the first study, 100 different acts presumably belonging to the category of dominance were generated through a nomination procedure. In the second study, expert and student panels rated how prototypically dominant each act is, defined in terms of centrality of membership in the category of dominant acts. In this manner, an internal structure of the act category was specified such that some acts are more prototypically dominant while others are more peripheral members. Substantial agreement in these ratings exists within and between panels. The third study found that a multiple-act criterion based on prototypically dominant acts is predicted by personality scales with significantly greater success than are multiple-act criteria based on more peripheral acts within the dominance domain. Discussion focuses on specifying the appropriate act category for other frequency dispositions and follow-up field studies of them. Implications for alternative notions of disposition (e.g., purposive-cognitive concepts) are considered.