Primary Submission Category: Gender
Beyond sex/gender: unique associations of sex and gender diversity with adolescent brain structure
Authors: Carinna Torgerson Jeiran Choupan Megan Herting
Presenting Author: Carinna Torgerson*
Decades of research have examined the relationship between sex and neuroanatomy across the human lifespan. Binary gender categorization makes it difficult to differentiate between sex and gender, and, as a result, few neuroimaging studies have examined the association between gender and brain structure, especially during childhood. In acknowledgement of the inability to distinguish between the two in neuroscience literature, many authors have begun to use combined terms such as “gender/sex” or “sex/gender.” Utilizing neuroimaging data and a continuous measure of gender diversity from the Adolescent Brain Cognitive Development℠ Study (ABCD Study®), this study sought to evaluate whether variance in brain structure is related to sex, gender diversity, or a combination of both by comparing a series of linear mixed effects models. We examined 5 common measures of brain structure: subcortical volume, cortical thickness (CTh), local gyrification index (lGI), fractional anisotropy (FA), and mean diffusivity (MD). The majority of variance in subcortical volume, lGI, FA and MD was best accounted for by the sex only model. In contrast, for CTh, the best model varied between sex alone, gender diversity alone, or a combination of sex and gender diversity. These results demonstrate that brain morphology is uniquely associated with both sex and dimensional features of gender. Furthermore, our analysis underscores the importance of testing the assumption that group differences between males and females are due to innate biological differences. Overall, these findings emphasize the need to carefully consider the role of sociocultural variables like gender in human biological research, including developmental MRI research, to improve efforts towards precision medicine.