I think missed the crucial part of the previous comment: when birth control was invented and countries became more egalitarian, the disparities between men and

I think missed the crucial part of the previous comment: when birth control was invented and countries became more egalitarian, the disparities between men and women in many professions increased. Societies where women still aren't permitted good accesses to reproductive control see higher rates of women in STEM. Had birth control been invented earlier, current trends indicate that disparities of women in STEM would be even greater.