(USA) - New evidence suggests genetics is a significant factor for whether an individual is homosexual or heterosexual. The findings emanate from a Canadian study of the brains of healthy, right-handed, 18- to 35-year-old homosexual and heterosexual men using structural Magnetic Resonance Imaging (MRI). The research, conducted by Dr. Sandra Witelson, a neuroscientist at McMaster University was a follow-up of a ten-year old study that demonstrated there is a higher proportion of left-handers in the homosexual population. The researchers also undertook a correlational analysis which included size of the corpus callosum, and test scores scores on language, visual spatial and finger dexterity tests. “By using all these variables, we were able to predict sexual orientation in 95 per cent of the cases,” she said.
