I think you misunderstood - he doesn't talk about the causes of the differences at all, just their existence. The very start of the article explicitly talks ab

I think you misunderstood - he doesn't talk about the causes of the differences at all, just their existence. The very start of the article explicitly talks about the difference between these things, how did you miss it? > Debates can be classified into two main types: (a) The description of sex differences, including both the size and variability of sex differences across a multitude of physical and psychological traits, and (b) The origins and development of sex differences, including the complex interplay between social, cultural, genetic, and biological factors that influence sex differences. > These lines often get blurred. ... > I believe that this blurring between the descriptive and the explanatory levels of analysis has stunted the field and distorted public debates over these complex and sensitive issues.