No Evidence for Enhancement of Spatial Ability with Elevated Prenatal Androgen Exposure in Congenital Adrenal Hyperplasia: A Meta-Analysis

Abstract

Spatial abilities contribute to life and occupational competencies, and certain spatial skills differ, on average, between males and females, typically favoring males when differences occur. Factors contributing to spatial skills could include prenatal as well as experiential/cultural influences, with biological and social influences likely interacting and difficult to disentangle. This meta-analysis examined the potential influence of prenatal androgen exposure on spatial skill by examining studies of patients with congenital adrenal hyperplasia (CAH). CAH involves elevated adrenal androgens prenatally, with overall androgen concentrations higher for females with CAH versus same-sex controls but with little overall difference between males with CAH versus controls. We hypothesized that, if androgens contribute prenatally to neurobehavioral development in humans as in many other species, females with CAH would show spatial enhancement versus control females, but with no definitive hypothesis for males. Meta-analysis of 12 studies examining overall spatial skill and three spatial subcategories failed to support enhanced spatial performance for females with CAH; males with CAH showed lower spatial ability compared to control males, at least for the category of overall spatial skill. Although statistical logic precludes accepting the null hypothesis for females, the meta-analysis failed to support the idea that prenatal exposure to androgens explains spatial gender/sex differences in humans. Alternative explanations for average gender/sex differences in some spatial tasks could include androgen exposure at other times, such as mini-puberty, or different social factors experienced by males and females. We also discuss possible explanations for the different outcomes seen in females versus males with CAH.

Keywords: Androgen; Congenital adrenal hyperplasia (CAH); Gender differences; Sex differences; Spatial ability; Visuospatial ability.

Figure 1.

Effect sizes (g) for overall spatial performance comparing patients with CAH to same-sex controls. F = females, M = males.

Figure 2.

Funnel plot of standard error in relation to effect size (g) for overall spatial performance comparing females with CAH to female controls. Higher precision (lower standard error) is observed for studies closer to the top of the graph.

Figure 3.

Funnel plot of standard error in relation to effect size (g) for overall spatial performance comparing males with CAH to male controls. Higher precision (lower standard error) is observed for studies closer to the top of the graph.

Figure 4.

Effect sizes (g) for mental rotation performance comparing patients with CAH to same-sex controls. F = females, M = males.

Figure 5.

Funnel plot of standard error in relation to effect size (g) for mental rotation performance comparing females with CAH to female controls. Higher precision (lower standard error) is observed for studies closer to the top of the graph.

Figure 6.

Funnel plot of standard error in relation to effect size (g) for mental rotation performance comparing males with CAH to male controls. Higher precision (lower standard error) is observed for studies closer to the top of the graph.

Figure 7.

Effect sizes (g) for spatial perception performance comparing patients with CAH to same-sex controls. F = females, M = males.

Figure 8.

Effect sizes (g) for spatial visualization performance comparing patients with CAH to same-sex controls. F = females, M = males.

Figure 9.

Funnel plot of standard error in relation to effect size (g) for spatial visualization performance comparing females with CAH to female controls. Higher precision (lower standard error) is observed for studies closer to the top of the graph.