pre-1984 most people in computer science were coming from adjacent professional fields and cross-trained. The computer programs in colleges weren't able to keep up with early and even current demands and that's a lot of the differences.

If you look at Scandinavian countries where equality of opportunity are enshrined in their culture, there's a broad variance of career choices between men and women as a whole.

Aside: I do feel that at least some of the differences can be attributed to the toy marketing which put the girl toys in the "pink aisle" and the computer games with the "boy toys" ... this has shaped a lot of culture and I think we're seeing things starting to normalize. But even of those women that I've worked with in software more than half move towards testing and management or out of the field within 3-5 years post-college.

The culture for software crafting tends to be one of strong negotiation and opinion, which tends to be unnatural for many women. I would like to see more education/training programs for women to get better and more comfortable with asserting and injecting opinion in a group setting. I think that would help, it still won't increase the natural variance, but it would probably keep more women in the development side of the coin.

All of the statements about "men" or "women" above are generalities, there are broad exceptions to everything said. There's a difference between outliers at under 20% and the norm.

Earlier today there were an article looking at gender ratios in professions between 1950 and 2015. Some professions flipped between being male and female dominated several times, and this without massive biological shift of both women and men, and multiple times.

A theory that tries to explain gender segregation need to explain why profession flip and sometimes oscillate between male and female dominance, why the gender equality paradox in places like Sweden where 85% of both women and men work in gender segregated work places, and why even within the same work place women and men tend to gender segregate even within the same profession (such as teachers gender segregating based on teaching subject).

A really old but fairly accepted theory is that a person feel more safe and confident when in the dominant group. People will thus have preference to such places. The theory is pretty good in explaining why people gender segregate but not why professions flip between male and female dominance. A common theory to explain that is than gender roles pushes men towards high income professions and socially punish those that don't, creating a preference for men but not women to prioritize high income professions over professions that offer other benefits.

It absolutely does not debunk the claim that women are innately less inclined to go into tech. Pre 1984, many professions like law, medicine, and more either were not accessible to women or were not viewed as socially acceptable. This resulted in displacement of women from these fields into other ones, like computing. Increased gender equality, especially in the 90s, led to more women going into fields like law, medicine, publishing, and more. Since double majors are rare, this increase of women in those fields necessarily comes with a reduction in women in other fields. Counterintuitively, the higher rates of women in computing during the 1970s and early 1980s can be viewed as the product of sexism that existed in much of society. This pattern holds true globally. The greater amount of gender equality a country has, the lower the share of women in engineering and technology.

While I am not pleased by lower diversity in computing as a result of this, I cannot bring myself to condemn the fact that women are freer to choose careers even if the result is less women in CS.