“Gay gene” researcher Dean Hamer was asked by Scientific American if homosexuality was rooted solely in biology. He replied:

“Absolutely not. From twin studies, we already know that half or more of the variability in sexual orientation is not inherited. Our studies try to pinpoint the genetic factors…not negate the psychosocial factors.”

Gene study.

From “New Evidence of a ‘Gay Gene’,” by Anastasia Toufexis, Time, November 13, 1995, vol. 146, Issue 20, p. 95.

What the majority of respected scientists now believe is that homosexuality is attributable to a combination of psychological, social, and biological factors.

From the American Psychological Association

“[M]any scientists share the view that sexual orientation is shaped for most people at an early age through complex interactions of biological, psychological and social factors.”

American Psychological Association’s pamphlet, “Answers to Your Questions About Sexual Orientation and Homosexuality.”From “Gay Brain” Researcher Simon LeVay

“At this point, the most widely held opinion [on causation of homosexuality] is that multiple factors play a role.”

From LeVay, Simon (1996). Queer Science, MIT Press.

From Dennis McFadden, University of Texas neuroscientist:

“Any human behavior is going to be the result of complex intermingling of genetics and environment. It would be astonishing if it were not true for homosexuality.”

From “Scientists Challenge Notion that Homosexuality’s a Matter of Choice,” The Charlotte Observer, August 9, 1998.

From Sociologist Steven Goldberg

“I know of no one in the field who argues that homosexuality can be explained without reference to environmental factors.”

From Goldberg, Steven (1994). When Wish Replaces Thought: Why So Much of What You Believe is False. Buffalo, New York: Prometheus Books.