Hello! I have been contemplating this question for a few days now and I am interested to know if anyone here has any input on the matter, and to critique my reasoning. There are other threads on this, none of which, from what I could find, made a distinction between homosexual behaviour and homosexuality. I would make the distinction between the two by arguing that homosexuality is a preference, in terms of sexual attractiveness, to the same sex, whereas homosexual behaviour is merely interaction between the same sex for various reasons - such as diffusing a tense situation, reinforce hierarchy - but not interaction because of a sexual attractiveness. For example, Bonobo chimps engage in genital rubbing, apparently to reconcile after aggression (from wiki), this however, is a behaviour that has evolved to maintain social relations within a group, and the individuals will engage in heterosexual relationships for the purposes of reproduction. There is plenty of evidence of homosexual behaviour in non-human species, but does anyone know of any evidence for homosexuality? I believe that there may be a continuum in terms of sexual attractiveness. Where individuals exhibit absolute preference for a particular sex at one extreme, and no preference (bisexuality) at the other extreme. For example, this is from The Atlantic Wire, claiming to quote Ed Yong (the science writer) saying: ' "Really, it's a bad idea to use terms like "gay" and "straight" when talking about mice at all. "When mice with normal levels of serotonin are given a choice between males and females, they will mount the male at least 20% of the time," points out Ed Yong. "This, and the widespread nature of homosexual behaviour in animals, supports the idea that sexual preference is more of a continuum." ' I disagree that homosexual behaviour supports a continuum, as I believe it evolved as a mechanism for communication within groups - to regulate groups, etc. - and is not to be considered when contemplating homosexuality. Essentially, it's a behaviour outside of the realm of sexuality. It should be analysed independently; such that the sexual preference of the individual has no bearing on the behaviour, although this may not be true for all behaviours, courtship behaviours for example, but other behaviours, like same sex genital rubbing, have evolved independently as a behaviours to communicate and regulate groups -it merely makes use of the physiological responses/motivations for sexual reproduction. The point about 20% of the time engaging in coitus with other male mice is the bit that is consistent with the continuum; the important point for homosexuality is if the reverse pattern has been observed: a male mouse which attempts to mate with male mice much more frequently than with female mice. This can of course be any animal, and I was wondering if anyone knows of any studies that make this distinction and have found this type of preference? I suspect the extremes in preference that are observed in many human societies is more a product of the culture. Anthropological studies seem to suggest many cultures involve homosexual behaviours amongst heterosexuals, and homosexuality is quite obviously, based on the testimonies of homosexuals - a natural preference for the same sex and not a product of culture. So perhaps bisexuality, to varying degrees dictated by genes, should be the 'default' for humans, and not this skewed absolute preference for a particular sex which is often observed. I believe this may be so as it is consistent with other species, in which homosexual coitus commonly occurs. Any input appreciated.