I'm very interested in this subject. I'm a gay guy myself, but I'm not by any means effeminate (lisping, mincing around, into musical theatre and so on). I'm not super macho either, or trying to be something I'm not. I (and most of my gay friends) are I suppose just normal guys in terms of mannerisms.
I'm a bit geeky in that I'm interested in technology, ancient history, warfare and military technology. I'm also a bit country-oriented; I ride, I shoot (and no, I mean in the sense of horses and shotguns, not copulation and ejaculation).
When I first came out (and this was a little bit before Grindr became big) I went out to some gay bars and my experience was that the denizens of the gay "scene" tended to be much more effeminate and campy than ordinary gay men I met outside the scene.
On the other hand, I do know some gay guys who are the stereotype of the lisping, musical theatre-oriented queen. I might be going out on a limb here, but my experience is that those sort of gay guys are more often "bottoms" (receptive partners) and that guys like me tend to be either "top" (dominant partner) or "versatile" (willing to switch it up... my personal preference as it's infinitely more novel and there's a sense of equality between the two guys).
I also find the homosexual couplings of the ancient world quite interesting; in Roman culture it seems it was quite normal for a man to be attracted to both women and male youths (I guess 15 to about 20). Some of the accounts of the Punic Wars I read was that when one of these cities was sacked, the soldiers fought each other over the most beautiful women and the most comely lads. I can't remember which historian it was (Livy, Tacitus, one of them) mentioned both in the same breath, with no apparent sense of soldierly preference for one or the other. The Romans didn't care what a freeborn male citizen did with his slaves or prostitutes, male or female, as long as he didn't let himself be penetrated. The Greeks did seem to allow some degree of male love between freeborn male citizens (probably too long a subject to get into here)
So I've wondered is it possible that, biologically, there are two types of gay men? There are gay men who are more like me, who are attracted to other guys and have broadly the same mindset as heterosexual men in terms of mannerism, mindset and so on. And then there is a second category of gay man who perhaps has a more female mindset, hence the effeminate behaviour.
Finally, I am certain that effeminate behaviour among gay men is becoming rarer (it seems more common among older gay men); in the old days to meet other gay men you had to go through the gay scene, which by virtue of being located in and a part of the entertainment industry (clubs, drag queens, rent boys) encouraged a more effeminate group behaviour which people would adopt due to peer pressure. But in the modern day where gay men can meet each other through the internet they can do so according to common interests and without that pressure (for example, the "gaybros" subreddit for gay guys who are into sport, hunting, fishing, shooting etc).
What do you think?