A new study suggests that transsexualism and gender identity development may be ingrained in our genetic makeup. A DNA analysis of 112 male-to-female transsexuals found that most had a longer version of the androgen receptor gene—a genetic trait that is associated with "less efficient" testosterone signaling. Recently, studies have found a biological basis for transsexualism in some people, including a study that found male-to-female transsexuals have a more "female like" brain structure. [BBC]