The paradigm of man as provider and woman as nurturer, and the mating ramifications of that (i.e. women preferring men who are able to provide, which most closely translates in our society to wealth, and men preferring women more fit to raise children, which in our society most closely translates to healthy appearance) are virtually universal.
That would strongly suggest that it is genetic rather than cultural.
I agree that this is easy, but I am not sure that it is in fact accurate. To do so you must show that the particular cultural values you're exploring do not share anthropological linage. This is a very difficult problem. How do you propose to handle that case?
So would you draw the line from this evolutionary argument like so: men have a greater instinct to produce wealth or high status, which causes them to produce more startups.
The problem I have with this is that's its so vague. If we don't actually try to nail down or postulate an actual theory, people can be lazy and undisciplined in their thought. They might say, for example "here are some good reasons that the sexes might be intrinsically different; any existing difference is just the way things are, due intrinsically, and due to genetics". My point is that the disciplined way to approach this question is that you actually need to make specific predictions, or you risk degenerating into religious war.
So, in which ways is this instinct for men to provide manifested?
Compared to startups, law or medicine or finance seems a surer method to acquire status and prestige, and you probably come out ahead on average. More women are in these fields than in startups.
And physical science and engineering aren't particularly high prestige careers, nor do they make much wealth, nor do they seem to improve procreative chances. And these fields are particularly male centric.
So then usually someone points out that men like to take risks. They aim for the massive payoffs. If that's so, one should examine the structure of risks that men take versus women.
So, we have a set of hypotheses, backed up in varying amounts by data. Men are much more likely to do one off things to impress people. I guess this is called machismo. They're much more likely to take physical risks, or health risks. They may be more likely to take risks in their social stature, so long as they have little to lose. They're more likely to risk the state of a relationship for some impulse, someone or something that they want.
By contrast, I postulate, women are more likely to risk themselves emotionally. They are more likely to invest themselves in one particular friendship or relationship, even if it risks not panning out. Men, by contrast, fear commitment. They're more likely to keep their eggs out of one basket (see especially, for example, studies on the messaging patterns and viewing patterns and requests and satisfaction on dating sites). Women are more likely to invest themselves emotionally in some community, cause, person, or idea.
Doesn't this sound like a startup?
It's striking how many female entrepreneurs describe starting a startup like having a baby. Mena Trott (in founders at work) describes it like having a chemical in your brain that blocks out the painful moments, leaving only the other ones in memory (This effect is described also of pregnancy, and recently they've actually discovered that such a chemical exists). Are women more ready to devote themselves like this? Are women more emotionally prepared for a startup? Perhaps.
So, we have conflicting attitudes towards risk. On one hand, we postulate, men are more likely to be driven by promises of extreme status and wealth. On the other, women are perhaps more emotionally prepared, in some areas, when they get there. It seems like this should be a fairly balanced game.
But it's not. Female founders make up 3% of the YC pool. The risk and wealth hypothesis can't handle this alone.
Something has to take up the slack. And I think that it has much to do with the fact that different memes that define success in this society propagate to men and to women.
You should really read up on evolutionary psychology, I think you might enjoy it.