Prenatal testosterone and theory of mind development: Findings from disorders of sex development

Women on average perform better than men on the "Reading the Mind in the Eyes" test (RMET) which is a measure of Theory of Mind (ToM). The aim of this study was to assess whether these sex differences are influenced by differences in prenatal testosterone levels through a study on individuals with Disorders of Sex Development and matched controls. ToM performance was examined using the RMET in female-assigned-at-birth individuals with increased prenatal testosterone exposure (Congenital Adrenal Hyperplasia (CAH) and 5-alpha Reductase type-2 Deficiency (5α-RD-2)), female-assigned-at-birth individuals with testosterone insensitivity (Complete Androgen Insensitivity Syndrome (CAIS)), and their age-matched unaffected male and female relatives. A total number of 158 individuals participated in the study; 19 with 5α-RD-2, 17 with CAH, 18 women with CAIS, 52 matched unaffected men and 52 matched unaffected women. All subgroups were around 20 years of age. Women with CAH scored significantly lower on RMET than control women and CAIS individuals. CAIS individuals scored significantly higher than control men and participants with 5α-RD. Statistically, CAIS individuals' performance on RMET was similar to control women's, women with CAH did not differ significantly from control men and 5α-RD-2 individuals scored significantly lower than control men. These results, which are in line with previous theories, illustrate that performance on the RMET, as an index of ToM, may be influenced by variations in prenatal androgens levels.