The theory of "male homosexuality as infantilization" explains things better than other popular theories, such as "gays as effeminate" and "gays as hyper-masculine." Females are more neotenous (child-like), hence we would expect similar things from the competing theories that gays are infantilized vs. that they are effeminate. It's hard to distinguish between them.
Some crucial test cases exist where the predictions are different, and the real world pattern clearly points to the infantilization theory. For example, females like to nurture creatures and other people, they dream of getting married, settling down, and starting a family, and as little girls they indulge these instincts by playing with "baby care" dolls -- the ones you cradle, feed, burp, change their diaper, and so on. Little boys couldn't be more turned off by a toy.
And sure enough, gays have no nurturing instinct, are not interested in getting married, settling down, and starting a family, nor do they play with baby-nurturing dolls (despite often playing with dress-up and fashion dolls). Queers are like little boys who never mature beyond their "girls are yucky" and "babies are stupid" phase.
Still, they do have quite effeminate tendencies as children, and that can't be explained directly by viewing them as Peter Pans. Why don't they do little boy activities and get stuck in them, rather than play with dolls, play dress up, and other little girl-y activities?
Steve Sailer linked to an ancient NYT article on gays -- before the movie Philadelphia came out -- in which several researchers on homosexuality make an interesting observation about distant fathers and boys who will grow up to be gay. It's not that distant fathers cause sissy-ish (and ultimately homo) behavior, but instead that boys who are already firmly down the path of sissy and homo behavior alienate their own fathers.
Mothers aren't so disgusted by a little boy who insists on behaving like a baby his whole life -- it gives mothers something to continue mothering -- so they become the refuge for the sissy boy. From there (and perhaps from any sisters he has), the soon-to-be-gay boy picks up so many feminine interests and hobbies.
Except for all those nurture-related activities. That's programmed at too deep of an instinctual level for a little boy to be able to ape the mindset and behavior of his mother or sisters.
It seems like the same dynamic would play out in his relations with boys outside the nuclear family. A stubbornly babyish, self-centered, Me Me Me little faggot will alienate all potential friends he could make on the playground. Boys are more team-oriented, and show little forgiveness for this kind of spoiled behavior.
Girls are more pair-oriented, so he may be able to find a handful of girls to relate with. They won't mind as much that he's an egocentric twit -- girls expect one another to be pretty self-centered and attention-whoring to begin with. Plus: finally a boy who doesn't try to push them down, taunt them, and so on. I know it sounds mean to describe these little girls as proto-fag-hags, but I bet these unusual girl / gay interactions begin earlier than we assume. It's not like it just kicks in out of nowhere when they begin adolescence or young adulthood and are looking for a gay bff to boost their hip status.
At any rate, the effeminate mannerisms and interests that queers show are likely an epiphenomenon. The underlying cause is their infantilization, which ultimately results in their being ostracized by males inside and outside the family, and coping with rejection by joining girl world and adopting its ways, within the bounds set by male instinct.