Thanks - I am actually not that interested in the variability hypothesis, as I would expect other factors to be much more important. So I guess I won't spend the time to read the paper in detail. The summary mentions that variability seems to be the lowest in countries with the most gender equality. That doesn't seem to contradict the notion that some inequality is caused by variability - after all, you could read it the other way round, where there is high variability, it leads to gender disparity.
I've come to jokingly say that a bad maths teacher at primary school could be worth millions of $ in damage compensation. It must be the primary school maths teacher fault that you didn't make a high earning STEM career, right? Except of course nowhere in society is math talent really supported, most math talents are mostly on their own (just my impression, though).
To me differences in incentives seem likely to have a much higher effect. It doesn't pay off for women to take risks, or not nearly as much as for men. Women have biological value in their own right (reproduction machinery), whereas men are much more expendable. To get ahead, men have to take higher risks - nobody will care for an average man. And men can gain extreme advantages in reproduction by taking risks and winning (even fathering thousands of kids like Ghengis Khan).
On the other hand consider that for a woman planning on becoming a housewife with no special skills is actually a viable strategy. Few feminists will consider that because they are biased by their own preferences, but if only a fraction of women take the "easy" route, it will show in things like pay gaps and percentages of women in certain types of jobs. (Btw I don't think any of the pay gap studies take into account that women typically get half of their husbands income - I assume that is also the case in the US?). For example that recent hype of "we need more women in action movies" is complete nonsense, because women simply don't have the incentive to put themselves into risky situations where they might be shot to death. Yes, there are exceptions, but on average there will simply be fewer women who will do that. So demanding that 50% of action heroes should be women is simply bullshit. It's not role models that makes women not clamor to get themselves killed, it is simply that they have no need to do so (apparently even the women joining the army are exposed to much less risk because they get different jobs than men).
As for the plethora of feminist movements, does that mean one can't criticize feminism? I don't think so. Most of them seem to have in common that they blame men for suppressing women. I know that some acknowledge that the "patriarchy" hurts men, too (although how prominently it features in their campaigns is another matter). It is still an ideology of victims.
The crazy thing to me is that feminists don't just get it a little bit wrong (in my opinion) - in many cases they get it 180° wrong, exactly the opposite of what they believe is true.
Examples: women are not pressured into becoming housewives (as feminists believe), they have the privilege of having the option to become housewives - try to plan on becoming a stay at home dad? (This is actually one of the points where feminists believe they also help men, but they overlook that they simply have the higher biologically claim to be stay at home, because they invest so much energy into child bearing. I don't expect a huge shift towards stay-at-home daddying).
Or rape culture: our culture does not condone rape, as feminists believe, it actually sees rape as an especially horrible crime. Therefore it is given proportionally more attention than other crimes - men are much more likely to be attacked on the street, but the disproportionate rape scare makes us feel as if women are more endangered. Also every movie or book uses rape as an easy way to evoke emotions (because it hits us especially hard), adding further to the distorted conception of the prevalence of rape. Scantily clad women in advertising are of course weird, but they don't signal women are readily available everywhere - they signal that you have to work a lot, get rich and buy a fancy car to attract women. Quite the opposite - if men would really believe that women were readily available without them having to show economic viability, they'd stop working and the economy would go to ruins immediately.
And so on, and so on...