Biological and psychosocial correlates of adult gender-variant identities: New findings

This study examined biological and psychosocial variables that are relevant to the etiology of gender-variance. Data were collected over the internet from 2277 participants of either gender who identified as transsexual, other gender-variant, and not gender-variant. We found number of gender-variant relatives, handedness, emotional abuse, finger length ratios (2D:4D), and systematizing significantly predicted Adult Gender-Variance among participants of both genders. Adult Gender-Variance was also predicted by number of older brothers among birth-assigned males. No significant differences were found in extreme right-handedness or mental rotation. No significant interaction effects were found with sexual orientation. While these findings are generally consistent with past research, there were limitations of the internet-based methodology, including a non-representative sample.