> It seems unlikely to me that social norms alone could cause gender dysphoric people to believe so strongly that their gender identity mismatches their biological sex
I think it's quite likely.
As an analogy, it seems relatively common for people to become so convinced that they are so unattractive that they undergo highly invasive cosmetic surgery. It's also very much the case that there are social groups where this is normalised (and many people in those social groups will choose to have this surgery) and social groups where it is not (and people in those groups are unlikely to opt for cosmetic surgery).
The difference seems to be that the people in one social group are telling each other that the appropriate solution to feeling unattractive means that one is unattractive and that surgery to change one's body is an appropriate response to that, whereas in the other social group people might either convince each other that they're attractive as they are, or seek alternative remedies such as changes in clothing, grooming, make-up, etc. Or even therapy, self-esteem coaching or similar.
Similarly, if one is an environment where one is constantly told that men (or women) are or should act/be a certain way, then it is hardly surprising that one might develop the notion that one isn't a man/woman. Such an environment is commonly created by people with traditional notions of gender. But it's reinforced by people suggesting that transitioning might be the solution to not fitting one's gender norms.
Which isn't to say that there aren't people for whom physically transitioning is the right answer (the best solution for them), or that do have an inherent dislike of their body that isn't externally influenced. Likewise, there are people for whom cosmetic surgery is absolutely the right solution (e.g. people with a cleft palate or who have suffered from severe burns). But I question the way it currently seems to being positioned (by some people) as the default response to not fitting in with the norms of one's existing gender, and I also question the idea that it is innate and not socially influenced.
I think it's quite likely.
As an analogy, it seems relatively common for people to become so convinced that they are so unattractive that they undergo highly invasive cosmetic surgery. It's also very much the case that there are social groups where this is normalised (and many people in those social groups will choose to have this surgery) and social groups where it is not (and people in those groups are unlikely to opt for cosmetic surgery).
The difference seems to be that the people in one social group are telling each other that the appropriate solution to feeling unattractive means that one is unattractive and that surgery to change one's body is an appropriate response to that, whereas in the other social group people might either convince each other that they're attractive as they are, or seek alternative remedies such as changes in clothing, grooming, make-up, etc. Or even therapy, self-esteem coaching or similar.
Similarly, if one is an environment where one is constantly told that men (or women) are or should act/be a certain way, then it is hardly surprising that one might develop the notion that one isn't a man/woman. Such an environment is commonly created by people with traditional notions of gender. But it's reinforced by people suggesting that transitioning might be the solution to not fitting one's gender norms.
Which isn't to say that there aren't people for whom physically transitioning is the right answer (the best solution for them), or that do have an inherent dislike of their body that isn't externally influenced. Likewise, there are people for whom cosmetic surgery is absolutely the right solution (e.g. people with a cleft palate or who have suffered from severe burns). But I question the way it currently seems to being positioned (by some people) as the default response to not fitting in with the norms of one's existing gender, and I also question the idea that it is innate and not socially influenced.