Causes of transsexuality Docter and others, but opposed by Charles Allen Moser, Larry Nuttbrock, Julia Serano, and the World Professional Association for Transgender Health.<section end="factors" /> A 2008 study compared 112 male-to-female transsexuals (both androphilic and gynephilic), mostly already undergoing hormone treatment, with 258 cisgender male controls. Male-to-female transsexuals were more likely than cisgender males to have a longer version of a receptor gene (longer repetitions of the gene) for the sex hormone androgen or testosterone, which reduced its effectiveness at binding testosterone. The androgen receptor (NR3C4) is activated by the binding of testosterone or dihydrotestosterone, where it plays a critical role in
Sexual Preference (book) Sexual Preference (book) Sexual Preference: Its Development in Men and Women (1981) is a book about the development of sexual orientation by the psychologist Alan P. Bell and the sociologists Martin S. Weinberg and Sue Kiefer Hammersmith, in which the authors reevaluate what were at the time of its publication widely held ideas about the origins of heterosexuality and homosexuality, sometimes rejecting entirely the factors proposed as causes, and in other cases concluding that their importance had been exaggerated. Produced with the help of the American National Institute of Mental Health, the study was a publication of the Institute for