Gender Dysphoria and Transgender Identity Is Associated with Physiological and Psychological Masculinization: a Theoretical Integration of Findings, Supported by Systematic Reviews

Introduction Gender dysphoria (GD) is associated with several psychiatric conditions, but the causal links are not known. We note that some of these conditions are associated with physiological masculinisation. Methods Here, we explore this association through a series of systematic reviews, using Google Scholar, on original studies that test the relationship between GD and at least one correlate of androgens, namely autism spectrum disorder, left-handedness, 2D:4D ratio, being male and male heterosexuality. Results Individuals with GD tend to exhibit scores that reflect heightened levels of androgens and masculinity compared with non-GD individuals. We further show that these same androgen indices are also associated with other identity disorders (or dysphoriae). Conclusions Autism is associated with masculinisation, and we argue that GD may reflect autism spectrum disorder traits that indirectly lead to anxiety and to one questioning one's sense of self. We note that this is consistent with Blanchard's transsexualism typology, which successfully integrates a wide range of empirical findings.