From: Nick N 22/10/99 21:10:43 Subject: Gay people post id: 1845 Does homosexuality originate from birth, or is it developed? If it is present at birth, is it supposed to be an evolutionary advantage, or is it a defect? If it is developed, then either it must come from non-mental factors or it must be learned as a behaviour. Would this then mean that a gay person can change to a heterosexual? Nick From: Dr. Ed G (Avatar) 22/10/99 23:35:53 Subject: re: Gay people post id: 1869 That is an excellent question, and one to which there as yet are no clear cut answers - partly because most people don't truly understand the question. The first thing that must be understood is that human sexuality is, like most human behaviour, extremely difficult to properly categorise. This is because humans don't exhibit one or to easily demarked and defineable types of behaviour, but a vast and varied spectrum of behaviours or this type, that type, and everything in between. So it must therefore be understood that there is very rarely one singular cause for any given human behaviour. To take the example of human sexuality, not everyone is strictly exclusively homosexual or exclusively heterosexual (I don't accept the proposition of some, however, that we are all intrinsically bisexual), and bisexuality ranges from mostly gay with a dose of hetero experimentation to mostly hetero with a dose of gay experimentation. And then of course there's an infinite variety of ways in which both homosexual and heterosexual couples relate and interact, and then there's people who are by persuasion (as opposed to religious canon) entirely celibate. So what is the nature and what are the causes of any given sexual behaviour? There are three potential factors that influence an individuals development, genetics, social environment, and developmental noise. One of the most well known of investigations into the possible genetic origin of homosexuality was done a few years ago. The result suggest that if a gene does exist for some forms of male homosexual orientation, they isolated a small section of chromosome where it might lie. They did not isolate this gene, or even adequately prove that it exists. Furthermore, the study was done on only a small group that had been carefully selected from a larger group of gay men. So the finding only relates to a fraction of a subgroup of male homosexual behaviour, and of course doesn't consider female homosexual behaviour. If there does exist a genetic predisposition for homosexual orientation it is arguable whether it is an adaptive trait (evolved through a process of natural selection), or simply an extra facet of human genetic variation, that is neither evolutionarily good or bad, but just is. It has been argued that genetically caused homosexual behaviour could have evolved because of the advantages it imposes on group selection - if you have a certain proportion on non-reproductive individuals in a group they can help ensure the survival of the offsring of closely related kin (brother, sisters, cousins, etc.) Certainly there is no scientific basis on which you could justify calling any such genetic disposition a defect. (again, it should be stressed that there is no hard evidence to unequivocally support a genetic basis for human homosexuality) The second possible influence on human sexual behaviour (or indeed any human behaviour) is of course upbringing and environment. Up until recently, it is my understanding, the clinical psychological establishment considered homosexuality to be a mental illness which, with the right therapy, could be "cured". This is still the belief of many religious theologians. Again, no study of which I am aware as been able to establish any clear link between factors in an individual's upbringing (say, the loss of a father at a young age, or an overly effectionate or protective mother [two common hypotheses for male homosexuality]) and homosexuality. Certainly the vast majority of attempts to "reform" homosexuals into heterosexuals have failed dismally, ending as often as not in suicide. I think its fairly safe to say that human sexuality is one of those things that is largely "hard wired" into an individual's make-up - not necessarily completely unchangeable or static, everyone changes their behaviour in different circumstances and throughout their lives, but I don't think it's something you have much of a choice over. The third factor, one which there is much more evidence for with respect to sexual behaviour in laboratory animals, is the noise associated with foetal development before birth. It has been demostrated that certain breeds of mice are more likely to exhibit homosexual behaviour if their mother was subject to stress during gestation. It has been suggested that when a pregnant female mouse is put under stress, the mix of hormones exposed to the uterus is such that the subsquent children are more likely to be "homosexual". It is then posited that this mechanism is an adaptive means of responding to overpopulation metagenetically (which out altering the genetic variation). It would be incorrect, however, to suggest a one-to-one equivalence between the sexual behaviour of mice and human sexual behaviour. My personal explanation for the wide variation in not only human sexual expression, but most human behaviour, is perhaps less satisfying in an empirical sense, but more likely given the phenomenal complexity of a human brain. One of the most important things any group or species can have is variation. Variation is the basis of evolution. Variation is the means by which a group can adapt to changing circumstances and ensure its long term survival. [CONJECTURE MODE ON] Human societies are gregarious, and they are complex. One way of making the most of the concentrations of individuals that people like to gather in, and to give them all something to do without too much redundancy, is to give each of those individuals different talents, skill, and behaviours, irrespective of their genetic heritage. This is achieved by the astonishing complexity of the human brain, and the fact that if you wire it up in one way you get someone with the potential to be William Shakespeare, but if you wire it just slightly differently you get someone with the potential to be Albert Einstein, and everywhere in between. And the complexity of the human brain is the almost unimagineable numerous actions, interactions, and interplays between the genes, the random development influenced by the chemical environment and stochastic processes in the womb, and the environment. They each play their part in determining an individual. As a result of all this, one has to expect there will be a wide variation in all sorts of human behaviours, including sexual. And while it may be almost impossible to determine the behavioural outcome of a given individual's life history (genetic, biological, and social), it is quite possible that what looks random on an individual level, is in fact determined on a group or species level. I very much believe that homosexuality, and heterosexuality, and bisexuality, and celibacy and everything in between, are all crucial facets of what makes our species the rich, creative, innovative, and evolutionarily robust species that it is. It's all part of the rich tapestry of life. Soupie twist, Ed G. p.s. as an aside on the common suggestion that homosexual behaviour is unnatural because it does not result in procreation, the same could be equally said of any sexual intercourse not strictly intended for procreation (i.e. using contraception, or having sex outside the fertile part of the reproductive cycle). From: Cam 23/10/99 15:52:02 Subject: re: Gay people post id: 1973 Being one of those 'gay people', and not at all reactionary against questions like this (i have often wondered myself), I have been or can remember being attracted to males as soon as the hormones began to flow. No single event in my life (as far as I veiw my life) has ever triggered me to be homosexual. I am. It is interesting to note, that as a young boy, I made friends with girls much more easily than with boys. This is a trait that continues today. I vote genetic, but you've gotta love Dr Ed's [Conjecture Mode]! And no, that is not a pass. I'm here to learn about science, mostly physics. There are places and times for such things. SHH!! ps: I am not political about my sexuality, if it bothers you, it bothers you. *shrugs* what am I supposed to do? Shout? march? light a candle? make a quilt?! no, i think i'll move on to find the answers to some important questions about the physical universe. :o) This forum is un-moderated. The views and opinions expressed are those of the individual poster and not the ABC. The ABC reserves the right to remove offensive or inappropriate messages.