I actually somewhat agree and have a theory on this. I've noticed more women than men are bisexual or bicurious or at least willing to admit to having the odd girl crush even if they don't act on it- if you're willing to sit through a gender roles rambling:
I watched a film called Call Me By Your Name a little while ago with a straight male friend of mine and I was really blown away by how beautiful it was and how the camera scanned the male body in a way that showed it off as a beautiful object. Men's bodies in films are usually either
neutral or
powerful, I think, and people who are interested in the male body rarely get treated to it like you do in that film.
You can get a feel for it w/ the trailer. Straight male friend said he liked the movie but was really put off by / really uninterested in looking at the male body for 2 hours. To me, this was weird because the female body is usually always displayed this way,
even when aimed at straight women, so the thought of being uncomfortable seeing your own gender displayed erotically was really foreign. I think since women are always pictured as sexual and beautiful, everyone (including straight women) are trained to see them that way and thus bisexuality doesn't seem that much of a stretch. Hence, more bisexual or bicurious women. Men rarely see other men like that (unless you know you're gay and go looking for it) so they never get shown how the male body can be beautiful, and thus never have their mind wander in that direction to become (bi)curious about it. That's my theory anyway
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To get back on topic - I actually don't think it would change much. I think there's a general assumption that T is masculine and F is feminine. Te and Se are the most masculine, meaning Alpha SF and Delta NF are the most effeminate types and Beta ST and Gamma NT the most masculine. Probably if you did a survey of those types the actual gender of those types would match the stereotypes (as in, there's probably more male LIEs than female and more female SEIs than male). But since that's a trend and not a rule then being homosexual shouldn't actually change the dynamic anymore than a switch in gender roles. What I actually quite like about socionics is it doesn't matter if you are a male EII and therefore not 'masculine' because out there is a female LSE possibly wondering if she is not feminine enough, whereas you're both perfect for each other. The more the EII tries to turn himself into the uber masculine SLE / LIE, the further he gets from his dual so he can just be himself. Thus since T isn't necessarily male and F isn't necessarily female, there's also no reason why they can't both be the same gender.
The only way I'd see it changing is possibly people trying to compensate for their perceived lack of conformity by downplaying their non-conforming IEs. So if a LSE woman feels the pressure to be 'nice' or expressive or whatever she might learn to emphasise her Fe role more than a male LSE and thus not be as clear a LSE for her dual. But this would be the case whether or not the EII is male or female. I guess the only difference in a gay relationship is at least one party is going to be gender non-conforming (iff you accept the premise that F is feminine and T is masculine) so it might be more prominent an issue.