W HAT IS THE S CIENCE BEHIND HOMOSEXUALITY ? A SOCIAL POLICY REPORT Homosexual behaviour is a nearly universal phenomenon in the animal kingdom. It is common across species, from worms to frogs to birds, concludes a recent literature review of the area. There is a strong possibility that homosexuality is normal in a biological sense, that is, it is a behaviour that evolved as an important element of early human social organisation. Homosexuals may be some genetic carriers of some of mankind’s rare attributes. Although homosexuality is mostly common in animals it finds its expression in the most intelligent of primates. Neurologists have known for decades that our genes largely shape the physical structure of the brain during prenatal development. Our genes determine the size, shape, connectivity of the lobes and nuclei, the basic plan of the cerebral cortex, and the quantity of grey matter in different regions that affect language and reasoning.
Physical brain geometry has effects on our thinking, feeling and
behaviour. People who are born with variations in geometry have variations in the way their minds work. Studies done on various subjects, determines both structural and functional brain differences to be highly correlated with sexual orientation. According to Swaab, this difference in structure and function develops during the foetal and neonatal phases.
LeVay [3], in his study done in 1991, established that the anterior
hypothalamus, the region controlling the secretion of sex hormones from pituitary gland, in non-primates is the cause for the typical male sexual behaviour. This was tested on male monkeys, where damage to this area resulted for the monkeys to have heterosexual behaviour impaired but still maintain their sexual drive.
When the equivalent of the human