Sex differences in g: An analysis of the US standardization sample of the WAIS-III

This study employed both hierarchical and Bi-factor multi-group confirmatory factor analysis with mean structures (MGCFA) to investigate the question of whether sex differences are present in the US standardization sample of the WAIS-III. The data consisted of age scaled scores from 2450 individuals aged from 16 to 89 years. The findings were more or less uniform across both analyses, showing a sex difference favoring men in g (0.19–0.22d), Information (0.40d), Arithmetic (0.37–0.39d) and Symbol Search (0.40–0.30d), and a sex difference favoring women in Processing Speed (0.72–1.30d).

► We used the US standardization sample of the WAIS-III.
► Sex differences in means were examined using multi-group factor analysis.
► Men showed an advantage in g, Information, Arithmetic, and Symbol Search.
► Women showed a large advantage in Processing Speed.