I absolutely disagree that gender is only a social construct.
Men and women have significant and universal behavioral/psychological differences that cannot be explained away as solely social construct. You could win the argument on hormones alone, though I’m sure there’s more at play. We know that testosterone and estrogen have a significant impact on behavior (such as testosterone being associated with aggression). We know that biological males and biological females as a trend have very different levels of these hormones. Ergo, biological men and biological women have significantly different behavior (as a trend).
Biological men have higher rates of suicide, higher rates of schizophrenia and a number of other mental illnesses, commit more crimes, etc. etc. Of course all of this has a degree of contribution from social factors, but the gaps are so wide you couldn’t possibly argue that it’s social alone. Not to mention, if you concede that life experience contributes to personality and character, the physical components of gender must also undeniably contribute to experience and thus indirectly to personality and character (ie men are significantly larger and stronger than women, don’t have periods, don’t undergo childbirth). I think it’d be pretty hard to argue that this difference isn’t a significant contribution to life experience with or without societal influence.
The way I see it is that society acts as a magnifying class for biological driven variation. Men and women are both physically and psychologically different and society magnifies the the difference that was there to begin with.
The concept of two genders, male and female, are just labels we apply to the general trend we see in people who are biologically male and people who are biologically female. In the end though, as with all such generalizations and labels, they only describe trends and there are always outliers who don’t fit the trend well. These are trans people, and there’s nothing wrong with that and their identification should be accepted.
It gets much more muddled when you go on tumblr and people argue that there are 25 million different genders and everyone should be allowed to identify as whatever they please. You can’t really let people invent whatever they want and call themselves that because then terms and categories lose all meaning as they are whatever the person wishes them to be. The gender binary emerged because it is a powerful descriptor of real trends observed across those who are biologically male and biologically female. At the same time, you can’t disregard anything but a shallow interpretation of the situation and say that those with male genitalia must identify as male and those with female genitalia must identify as female. The only tenable solution is a reasonable compromise between a person’s own invented or otherwise identification and the general consensus of society. Of course this system can only be as progressive as society, but in reality that is true of so many things and in many ways a pretty fundamental compromise and the way to fix it is to be an active participant in society and shift that compromise in the direction you see fit.