Not that you can really control all of the environmental factors, but at least with trans people on cross-sex hormone therapy you can control the between-subject variability.
This is an interesting thing, and it does make for some uncomfortableness. For instance, I remember reading the account of a transgender man who, after transition that included testosterone therapy, felt much sharper, focused and confident than he did with female hormones dominating. This suggests that the sexist assertion that women's hormones make us duller, more scattered, and spineless overall than men (or than we would be personally if we were men) actually is true.
Depressing to think I might have been smarter, more focused, and more confident if I'd been born with male hormones.
It made me want testosterone so I can be smarter, more focused, and more self assured but without the other side effects, like a deeper voice, hair in all the wrong places, and a through the rooftop libido (I spend too much time thinking about sex and feeling frustrated as it is, and if I were on Testosterone, eeeeek). And I don't want my emotions (except anger) to be dulled.
But one side effect of being at a time of life when my female hormones are decreasing is that I feel more fuzzy-brained, tired, and unfocused than I used to, so it may not just be the effects of testosterone so much as being deficient in a particular hormone that one's body is wired up to need. So maybe an aspect of being transgender, for some people at least, could be that their bodies actually need different sex hormones than they have by default to work optimally?
And is it true that men actually don't (aside from anger)
feel emotions as deeply as women do overall? Because my completely anecdotal experience with the men I've known is that the men I know (and the ones whose books I read) seem to feel love, joy, fear, sadness, jealousy, hate, loneliness etc. as intensely as I do and suffer terribly when their emotional needs aren't met, but they aren't always as good as articulating those feelings face to face.
I do remember hearing a neuroendocrinologist (Sapolsky) say in a radio interview that women, overall, are slower to anger but once aroused to anger, will tend to stay in that arousal state longer and be able to re-enter it more readily, which is the kernel of truth behind the stereotype that women are more likely to harbor grudges and bring up old arguments their menfolk think are settled and to tie current transgressions to ongoing patterns of behavior.
I'm not sure this typifies my overall experience, however. For me, whether I lose my temper quickly or do a slow burn is more about the mood I'm in. I'm likely to flare up more quickly f I'm hungry or tired, for instance, or if it's a hair trigger issue for me. And my dad, OMG, he never forgot old grudges or arguments. He'd bring up something hurtful (or stupid) you said in anger years later...
Anecdotes, I know, but this illustrates how hard it is to get a handle on these things. And how does one decide whether someone's account of their own lived experience is an anecdote of little importance in the overall scheme of things, or whether it's an important and overlooked variable?