 They consider sex categories to be dichotomous, and that the person is placed in a sex category by exhibiting qualities exclusive to one category or the other.During most interactions, others situate a person's sex by identifying their sex category; however, they believe that a person's sex need not align with their sex category.West and Zimmerman maintain that the sex category is "established and sustained by the socially required identificatory displays that proclaim one’s membership in one or the other category".