Weitere Studien, die verschiedene Faktoren für Geschlechterunterschiede untersuchen:
Both sexual orientation and sex-typical childhood behaviors, such as toy, playmate and activity preferences, show substantial sex differences, as well as substantial variability within each sex. In other species, behaviors that show sex differences are typically influenced by exposure to gonadal steroids, particularly testosterone and its metabolites, during early development (prenatally or neonatally). This article reviews the evidence regarding prenatal influences of gonadal steroids on human sexual orientation, as well as sex-typed childhood behaviors that predict subsequent sexual orientation. The evidence supports a role for prenatal testosterone exposure in the development of sex-typed interests in childhood, as well as in sexual orientation in later life, at least for some individuals. It appears, however, that other factors, in addition to hormones, play an important role in determining sexual orientation. These factors have not been well-characterized, but possibilities include direct genetic effects, and effects of maternal factors during pregnancy. Although a role for hormones during early development has been established, it also appears that there may be multiple pathways to a given sexual orientation outcome and some of these pathways may not involve hormones.
► Prenatal exposure to androgenic hormones influences human sexual orientation. ► Androgen dose predicts the likelihood of non-heterosexual orientation. ► Normal variability in testosterone prenatally predicts masculinity in childhood. ► Sexual orientation is predicted by masculinity/femininity of childhood behavior. ► Prenatal stress does not demasculinize boys, but may masculinize girls slightly.
Die Studie passt zu den anderen Studien. Pränatales Testosteron beeinflusst die sexuelle Orientierung, dass Verhalten während der Kindheit etc. Da die Auswirkungen zu dem Testosteronspiegel im Mutterleib passen, sind sie mit der Gesellschaft nicht zu erklären.
Die Rolle der Gene beleuchtet auch eine weitere Studie:
Biological differences between men and women contribute to many sex-specific illnesses and disorders. Historically, it was argued that such differences were largely, if not exclusively, due to gonadal hormone secretions. However, emerging research has shown that some differences are mediated by mechanisms other than the action of these hormone secretions and in particular by products of genes located on the X and Y chromosomes, which we refer to as direct genetic effects. This paper reviews the evidence for direct genetic effects in behavioral and brain sex differences. We highlight the ‘four core genotypes’ model and sex differences in the midbrain dopaminergic system, specifically focusing on the role of Sry. We also discuss novel research being done on unique populations including people attracted to the same sex and people with a cross-gender identity. As science continues to advance our understanding of biological sex differences, a new field is emerging that is aimed at better addressing the needs of both sexes: gender-based biology and medicine. Ultimately, the study of the biological basis for sex differences will improve healthcare for both men and women.
Zu den „Four Core Genotypes“
The „four core genotypes“ (FCG) model comprises mice in which sex chromosome complement (XX vs. XY) is unrelated to the animal’s gonadal sex. The four genotypes are XX gonadal males or females, and XY gonadal males or females. The model allows one to measure (1) the differences in phenotypes caused by sex chromosome complement (XX vs. XY), (2) the differential effects of ovarian and testicular secretions, and (3) the interactive effects of (1) and (2). Thus, the FCG model provides new information regarding the origins of sex differences in phenotype that has not been available from studies that manipulate gonadal hormone levels in normal XY males and XX females. Studies of the FCG model have uncovered XX vs. XY differences in behaviors (aggression, parenting, habit formation, nociception, social interactions), gene expression (septal vasopressin), and susceptibility to disease (neural tube closure and autoimmune disease) not mediated by gonadal hormones. Some sex chromosome effects are mediated by sex differences in dose of X genes or their parental imprint. Future studies will identify the genes involved and their mechanisms of action.
Das scheint mir recht interessante Forschung zu sein. Mal sehen, was sie noch erbringt.