Different Behaviors, Different Brains? HOME VARIATION PATHOLOGY GENDER & SEXUAL ORIENTATION

GENDER & SEXUAL ORIENT- ATION A Brief Gendered History Structure, Hormones, & Something Else? Individual Variation Pathology Bibliography & Links

Brain Structure--> Behavior? Let's look at another example before we try to answer that question. The bed nucleus of stria terminalis (BSTc) is located in the hypothalamus. Researchers have studed this area in male-to-female transsexuals and compared it with heterosexual males and females and homosexual males. Look at the images below and see if you can notice any differences: Heterosexual male Heterosexual female Homosexual male Male-to-female Transsexual (images thanks to this 1995 Nature article on sex differences and transsexuality) The article reports that the "BSTc volume in heterosexual men was 44% larger than in heterosexual women. The volume of the BSTc of heterosexual and homosexual men was found not to differ in any statistically significant way . The BSTc was 62% larger in homosexual men than in heterosexual women"(Zhou, 1995). So, it is thought that the volume of the BSTc may be related to how an individual chooses transsexuality. Researchers have seen that the volume of the BSTc does not change, even if additional sex hormones are administered during adulthood. So, this may be a gray area in the discussion about men versus women. What causes these differences in behavior? Is it hormones? Is it society? How is this information relevant to our discussion about brain and behavior? Can we talk about hormones a bit, please?? HOME || VARIATION || PATHOLOGY || GENDER || SEXUALITY || LINKS