Check out the newly published article by Laura Castellanos and Dick Swaab on \"Sexual Identity and Sexual Orientation\"\'
Abstract Sexual differentiation of the brain, gender identity (an individual\'s perception of being male or female), and sexual orientation (heterosexuality, homosexuality, bisexuality, and pedophilia) is orchestrated and determined in our brain during early development. Sexual differentiation of the brain is determined by a series of events, starting with the influence from the SRY gene on the Y chromosome, followed by the influence of sex hormones regulated by different mechanisms, through different paths and with different endpoints, including epigenetic modifications. These complex mechanisms ensure the variability, necessary from an evolutionary perspective; however, it also provides multiple points where it may be disrupted or modified, and therefore influence sexual behaviors. This chapter will review the literature regarding the genetic, postmortem, and in vivo scanning observations that support the neurobiological theory about the origin of our gender identity and sexual orientation. In humans, there is no evidence that one\'s postnatal social environment plays a crucial role in the development of gender identity and sexual orientation.
Sexual Identity and Sexual Orientation (PDF Download Available). = > Available from: https://www.researchgate.net/publication/310370114_Sexual_Identity_and_Sexual_Orientation [accessed Aug 21, 2017].