Androgens and the Evolution of Male-Gender Identity among Male Pseudohermaphrodites with 5α-Reductase Deficiency

Abstract

To determine the contribution of androgens to the formation of male-gender identity, we studied male pseudohermaphrodites who had decreased dihydrotestosterone production due to 5 alpha-reductase deficiency. These subjects were born with female-appearing external genitalia and were raised as girls. They have plasma testosterone levels in the high normal range, show an excellent response to testosterone and are unique models for evaluating the effect of testosterone, as compared with a female upbringing, in determining gender identity. Eighteen of 38 affected subjects were unambiguously raised as girls, yet during or after puberty, 17 of 18 changed to a male-gender identity and 16 of 18 to a male-gender role. Thus, exposure of the brain to normal levels of testosterone in utero, neonatally and at puberty appears to contribute substantially to the formation of male-gender identity. These subjects demonstrate that in the absence of sociocultural factors that could interrupt the natural sequence of events, the effect of testosterone predominates, over-riding the effect of rearing as girls.

Intersexuality and Alternative Gender Categories in Non-Western Cultures

“…Even though the gender identity of these individuals is poorly investigated, they seem – at least when left untreated – to develop a male gender identity [10]. In the Western-oriented Dominican Republic cases, after being reared as girls all individuals change into the male gender.…”

“…Individuals with a 5α-reductase deficiency are the only medically defined form of intersexuality for whom a separate and defined gender status is reported in two different cultures – the Dominican Republic [10] and Papua New Guinea [25, 26]; for the third group reported to live in the Taurus mountain range in Turkey, no psychological data have been made available to us. Affected individuals with an XY karyotype have male internal but feminized external genitalia.…”

“…It seems that through several generations the society has learned to recognize these children at birth. Imperato-McGinley et al [10] observed that almost all guevedoce while initially socialized as girls change into the male gender status, explained medically as reflecting the influence of testosterone during puberty upon the development of gender role and identity. In their interpretation, this experiment of nature proves the dominance of nature over nurture.…”

“…Until the first reports by Imperato-McGuinley et al [10], it was generally accepted that gender identity can be created through socialization and education during the first 2 years of life [11]. Subsequent outcome studies in patients with various disorders of sex development have shown that gender identity is the result of both nature (i.e.…”

Cloning and characterization of TDD5, an androgen target gene that is differentially repressed by testosterone and dihydrotestosterone

“…In addition to prior metabolic activation, T may directly activate the development of muscle where very limited 5␣-reductase activity is detected (6). From studies of inherited 5␣-reductase-deficient patients, investigators have concluded that T is able to stimulate psychosexual behavior and the development of Wolffian duct, muscle, voice deepening, spermatogenesis, and axillary as well as pubic hair growth (7,8). DHT seems to be necessary for the development of prostate and external genitalia, the male pattern hair growth, and male-form baldness (9).…”