> We will further assume that the distribution of Techiness is sex-specific; and that those sex-differences exist at birth and aren’t the result of later social

> We will further assume that the distribution of Techiness is sex-specific; and that those sex-differences exist at birth and aren’t the result of later social or environmental factors. That's a really strong assumption, and one that even the author of the "Diversity memo" didn't make, IIRC. In fact it would make sense to assume the exact opposite: Whatever the differences of "initial state" may be, they will compound over time in a "feedback loop". Another issue: "techiness" isn't the only or even the main factor considered when hiring employees. If you consider this vaguely defined variable a function of several other variables, some not related to technology at all (e.g. cooperation, willingness to work at a major corporation, to work long hours, alma mater, other job opportunities, etc) you're left with basically no way of estimating if the standard deviation differences between males and females are, say, 1.5x or 4x. The author also didn't combine simultaneously changes in mean and standard deviation on his analysis, and didn't consider the possibility that the traits might fit a different curve (e.g. Tracy-Widom)