Testing Biological Theories of Same-Sex Sexual Attraction and Transgender Identity: Somatic, Cognitive, Behavioural, and Demographic Markers

测试同性性吸引力和变性身份的生物学理论：躯体、认知、行为和人口标记

• 批准号: RGPIN-2016-06446
• 负责人: VanderLaan, Doug
• 金额: $ 2.4万
• 依托单位: University of Toronto
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2016
• 资助国家: 加拿大
• 起止时间: 2016-01-01 至 2017-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=616313
• 关键词: Testing; Biological; Theories; Same; Sex

Gender identity and sexual orientation are two of the largest psychological sex differences. The vast majority of people are cisgender (i.e., males identify as men, females identify as women) and exhibit opposite-sex attraction. Yet, exceptions to these fundamental patterns exist. Substantial minorities of people exhibit same-sex sexual attraction and/or transgenderism and, thus, provide unique human models for studying sexual differentiation of the brain, cognition, and behaviour. Hormonal, genetic, and immunological processes have been hypothesized to influence sexual differentiation of the brain and lead to within-sex variation in gender identity and sexual orientation. Previous research examined whether somatic, cognitive, behavioural, and demographic markers of these biological processes differentiate transgender vs. cisgender individuals on the one hand, and same- vs. opposite-sex attracted individuals on the other. Biomarkers associated with transgenderism are often also associated with same-sex sexual attraction. Yet, because no studies directly compared these biomarkers across same-sex attracted cisgender vs. transgender individuals, it is unclear to what extent, if any, these two phenotypes are underpinned by different biological processes. To clarify this issue, one must examine a population in which comparing groups of same-sex attracted cisgender vs. transgender individuals is feasible. In Western countries, transgenderism is rare and difficult to study outside of specialty clinics. Hence, the proposed research will be situated in Thailand where cisgender same-sex attraction is relatively common (2-5%) and, due to a lack of social censure regarding gender expression, transgender same-sex attraction is 50 to 250 times more common than in other populations. Thus, the Thai population provides a rare opportunity to compare same-sex sexual orientation and transgenderism as human models of sexual differentiation. Thai same-sex attracted cisgender vs. transgender individuals will be compared on a comprehensive set of relevant biomarkers. These include several markers linked to prenatal androgen exposure: brain structure (e.g., cortical thickness, white matter microstructure), second-to-fourth digit ratio, physical size (e.g., height, weight), face structure, cognitive abilities (e.g., mental rotation), and behavioural characteristics (e.g., handedness). To provide insight regarding genetic and immunological factors, familiality of transgenderism and same-sex sexual orientation and participants’ birth orders will be examined, respectively. By comparing same-sex attracted cisgender vs. transgender individuals on a comprehensive set of biomarkers, my research program will transform our understanding of how these respective human models and biomarkers shed light on sexual differentiation of the brain, cognition, and behaviour.

性别认同和性取向是最大的心理性别差异之一。绝大多数人是cisgender（即男性认同为男性，女性身份为女性），并暴露了异性吸引力。然而，存在这些基本模式的例外。大量的少数族裔表现出同性性吸引和/或变性主义，因此为研究大脑，认知和行为的性别分化提供了独特的人类模型。 假设荷尔蒙，遗传和免疫过程会影响大脑的性别分化，并导致性别认同和性取向的性别差异。先前的研究检查了这些生物学过程的体细胞，认知，行为和人口标志物是否一方面分化了变性者与顺式人的个体，而同性恋者与异性恋者则吸引了另一方面。与变性主义相关的生物标志物通常也与同性性吸引力有关。然而，由于没有研究直接比较了同性的这些生物标志物吸引了sisgender vs.变性人，因此目前尚不清楚这两种表型在多大程度上受到不同生物学过程的基础。 为了澄清这个问题，必须检查一个人群，在该人群中，比较同性的群体吸引了Cisgender vs.变性人的人是可行的。在西方国家，跨性别主义罕见，很难在专业诊所以外学习。因此，拟议的研究将位于泰国，在泰国，cisgender同性吸引力相对普遍（2-5％），并且由于缺乏对性别表达的社会谴责，跨性别者同性吸引力的普遍性比其他人群高的50至250倍。这是泰国人口提供了一个难得的机会，将同性性取向和跨性别主义与人类性别差异模型进行比较。 将在一系列相关的生物标志物中比较泰国同性与跨性别者的吸引与跨性别者。其中包括与产前雄激素暴露有关的几个标记：大脑结构（例如皮层厚度，白质微观结构），二到四分位数的比率，物理大小（例如，身高，体重），面部结构，认知能力（例如，精神旋转）和行为特征（例如，手工）。为了提供有关遗传和免疫因素的见解，将分别研究跨性别主义和同性性取向的家庭性以及参与者的出生命令。 通过比较同性的，在全面的生物标志物上吸引了Cisgender和Transformer个体，我的研究计划将改变我们对这些相对人类模型和生物标志物如何揭示大脑，认知和行为的性别差异的理解。