male and female leaves out everyone who does not fit into these categories because of genital make up, chromosomes, or hormone levels. Anne Fausto-Sterling addresses the issues facing intersex people in her article The Five Sexes. She claims that there is at minimum five sexes but probably more; this is based on the vast range of ways bodies show up in nature. She points out that, "recent advances in physiology and surgical technology now enable physicians to catch most intersexuals at birth... infants are entered into a program of hormonal and surgical management..." This highlights the intense adherence to the binary instead of allowing bodies to present in the world without intervention. West and Zimmerman also give a definition for sex category: "achieved through application of the sex criteria, but in everyday life, categorization is established and sustained by the socially required identificatory displays that proclaim one's membership in one or the other category". Sex category is applied to a person in everyday life through commonly recognized cues that are not necessarily fulfilling biological criteria of sex. In a different study by Wenzlaff et al., 40 participants in North America were asked whether schematic drawings of nude adults were male or female. The majority response was male for images including a penis, and a more evenly split response for images including a vulva; drawings included both congruent and incongruent genital and secondary sex characteristics, so the presence of a penis is the predominant determiner of perceived gender. Applications of gender performance The term gender performativity was first coined by American philosopher and gender theorist Judith Butler in their 1990 book Gender Trouble: Feminism and the Subversion of Identity. In the book, Butler sets out to criticize what they consider to be an outdated perception of gender. This outdated perception, according to Butler, is limiting in that it adheres to the dominant societal constraints that label gender as binary. In scrutinizing gender, Butler introduces a nuanced perception in which they unite the concepts of performativity and gender. In chapter one, Butler introduces the unification of the terms gender and performativity in stating that "gender proves to be performance—that is, constituting the identity it is purported to be. In this sense, gender is always a doing, though not a doing by a subject who might be said to pre-exist the deed". In demystifying this concept, Butler sets out to clarify that there