Does homosexuality objectively exist?
In recent years there has been a shift in western society to, for the most part, recognize that there are people who are healthy, normal members of society and also engage in homosexual relationships. These people are generally described as being homosexuals; their desire for a same sex relationships unifies them into one group.
Science has accepted that homosexuality exists and that it appears to be something biological rather than socially constructed. They've gone hunting for a "gay" gene or hormonal fluctuations in the womb that could trigger it.
Homosexual behavior has likely existed in humanity since before we had language. Some of our closest relations, the bonobos, regularly engage in same sex contact. In fact, the animal kingdom is full of homosexual behavior. Giraffes are noted as being "notoriously gay" by zoologists.
But, wait. There's a fallacy that's occurred somewhere here. Homosexual behavior may occur naturally, and homosexual behavior may have been present in humanity for millions of years, but homosexuality as we in the west recognize it has not.
In many cultures across the globe, it has been common for grown men to engage in sexual contact with teenage boys or young men. But forming long-lasting romantic relationships with them once they reached adulthood (in some Greek city-states this might come as late as the age of 30) was unthinkable. In several tribes in Papua-New Guinea, they believe that a boy can literally not become a man without being the receptive partner with another man for several years. When he reaches adulthood, he's then expected to be the penetrative partner, and eventually stop sleeping with men entirely.
The concept of Two-Spirit people was a fundamental institution among most tribal peoples in North America. It usually implies a a masculine spirit and a feminine spirit living in the same body. While it's often taken as "the Native American term for gays and lesbians", it is most certainly not. People in relationships with a Two-Spirit would not consider themselves to be a homosexual and would see a sharp divide between themselves and the Two-Spirits. Two-Spirit is not meant to be analogous to any other concept outside of the cultures that it originates from.
Statistics on male homosexual identity has found that those who don't engage in anal sex or only engage in it as the penetrative partner are less likely to identify as "gay". Throughout history, a similar attitude has been held wherein the receptive partner was seen as being the "other"--often viewed as feminized--while the penetrative partner would continue to hold the same position in society as men who did not engage in same sex relations.
So if the concept isn't a universal one and is in fact very, very recent, does homosexuality as we conceive of it even exist objectively, or is it simply another social construct surrounding the natural inclination to occasionally engage in homosexual behavior?