I wrote [in my book]:
“Studies on twins in fact make it perfectly clear that there can be no genetic basis for homosexuality. As one researcher in the field explains, ‘Identical twins have identical genes. If homosexuality was a biological condition produced inescapably by the genes (e.g. eye color), then if one identical twin was homosexual, in 100% of the cases his brother would be too. But we know that only about 38% of the time is the identical twin brother homosexual. Genes are responsible for an indirect influence, but on average, they do not force people into homosexuality. This conclusion has been well known in the scientific community for a few decades’.”
That particular expert is New Zealand researcher Dr Neil Whitehead. He has written extensively on these matters, including his important 1999 book, My Genes Made Me Do It! (Harvest House). He is still working closely on these matters, and a helpful update to his invaluable work has recently appeared.
Here is how one write-up discusses this new research: “Eight major studies of identical twins in Australia, the U.S., and Scandinavia during the last two decades all arrive at the same conclusion: gays were not born that way. ‘At best genetics is a minor factor,’ says Dr. Neil Whitehead, PhD. Whitehead worked for the New Zealand government as a scientific researcher for 24 years, then spent four years working for the United Nations and International Atomic Energy Agency. Most recently, he serves as a consultant to Japanese universities about the effects of radiation exposure. His PhD is in biochemistry and statistics.
“Identical twins have the same genes or DNA. They are nurtured in equal prenatal conditions. If homosexuality is caused by genetics or prenatal conditions and one twin is gay, the co-twin should also be gay. ‘Because they have identical DNA, it ought to be 100%,’ Dr. Whitehead notes. But the studies reveal something else. ‘If an identical twin has same-sex attraction the chances the co-twin has it are only about 11% for men and 14% for women.’
“Because identical twins are always genetically identical, homosexuality cannot be genetically dictated. ‘No-one is born gay,’ he notes. ‘The predominant things that create homosexuality in one identical twin and not in the other have to be post-birth factors.’ Dr. Whitehead believes same-sex attraction (SSA) is caused by ‘non-shared factors,’ things happening to one twin but not the other, or a personal response to an event by one of the twins and not the other.
“For example, one twin might have exposure to pornography or sexual abuse, but not the other. One twin may interpret and respond to their family or classroom environment differently than the other. ‘These individual and idiosyncratic responses to random events and to common environmental factors predominate,’ he says.”