There are a lot of people (in this case a lot of both males and females) who go to one end or the other - either behavioral differences between the sexes are completely created by society... or they're completely created by evolution.
Reality is that we're NOT blank slates, and there ARE differences in innate behavioral tendencies between males and females. It's reasonable that there should be, because we're a sexually dimorphic species where females bear almost the entire cost of reproduction due to the length of gestation and the length of immaturity in our offspring.
Males being bigger, faster, stronger, more violent, and more aggressive are all evolutionary adaptations which have historically served us well. Females being smaller, having higher fat content, being more collaborative and being more nurturing toward children are also evolutionary adaptations which have served us well.
But we're ALSO heavily influenced by social influences, and THOSE have a large impact as well.
I 100% agree with all this.
Males being expected to have leadership skills, be decisive, and to not show emotional vulnerability is probably NOT an evolutionary result, but a social structure. Women being expected to be subservient, soft-spoken, and not to have strong opinions is also probably NOT an evolutionary result.
This is where I think things get tricky. Yes, these things are largely socially defined. That doesn't mean that we can pick and choose whatever properties we want for men and women, or have no socially defined male and female properties at all and have a working society that lasts into the future.
All these characteristics are inter-related and are ultimately built on basic biological differences. Maybe you could socially engineer your way to a society where women were more aggressive and risk taking than men, but you are going to be rolling a stone uphill there and the stone is going to roll back down unless you keep pushing. There is going to be a tendency for socially defined differences to build on top of, reinforce, and exacerbate physical differences.
These characteristics are both inter-related within a particular sex, or gender, and between them. If men are stronger, women need to be attracted to strength and all the different socially defined ways men demonstrate strength. You can't change one sex without it having a knock on effect on the other.
You also have the issue, that these socially defined gender differences come out of a process of natural selection. Men whose way of being male doesn't result in children tend not to pass on that way of being male, socially defined though it is. The same with women. If people's ways of being male and female don't result in a strong and productive society, then the society collapses. This is another version of the Burkean argument about the French Revolution.
Socially defined is not the same as something being a consequence free choice.
Take a classic example of this, the idea that we need women to be equally represented in the workplace and career and so forth is how you define the success of a woman just as much as a man. Well, women delay settling down until their career is established, so you've raised the age that people are having children. Women still want a man who is more successful than them and able to provide for them, so you end up with a lot of disappointed women at the top end and a lot of sad lonely man at the bottom. Meanwhile society is no longer structured around the idea of a man supporting a whole household on one salary, so to maintain their lifestyle the woman goes back to work and all of a sudden you have less than replacement birth rates.
Having an idea of a liberal society where everybody is equal and there are no stereotypes about men and women, and there is nothing unusual about a female CEO or a male nanny is terrific, but I think it's far from clear that that doesn't lead to some kind of collapse.
Honestly, if men were what they were 50+ years ago in terms of feeling it was their responsibility to protect women, you would not have uninvited trans-women in female changing rooms. Maybe you like men having stepped back from these old fashioned attitudes? OK, but there is a price to be paid and a great many unintended consequences.
