Homosexual Twin Studies
Two American activists recently published studies showing that if one of a pair of identical twins is homosexual, the other member of the pair will be, too, in just under 50% of the cases. On this basis, they claim that "homosexuality is genetic."
But two other genetic researchers--one heads one of the largest genetics departments in the country, the other is at Harvard--comment:
While the authors interpreted their findings as evidence for a genetic basis for homosexuality, we think that the data in fact provide strong evidence for the influence of the environment.{2}
The author of the lead article on genes and behavior in a special issue of
Science speaks of the renewed scientific recognition of the importance of environment. He notes the growing understanding that:
... the interaction of genes and environment is much more complicated than the simple "violence genes" and intelligence genes" touted in the popular press.The same data that show the effects of genes, also point to the enormous influence of nongenetic factors.{3}
More Modest Claims to the Scientific Community
Researchers' public statements to the press are often grand and far-reaching. But when answering the scientific community, they speak much more cautiously.
"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."{4}
But in qualifying their findings, researchers often use language that will surely evade general understanding making statements that will continue to be avoided by the popular press, such as:
...the question of the appropriate significance level to apply to a nonMendelian trait such as sexual orientation is problematic.{5}
Sounds too complex to bother translating? This is actually a very important statement. In layman's terms, this means:
It is
not possible to know what the findings mean--
if anything--since sexual orientation cannot possibly be inherited in the direct way eyecolor is.
Thus, to their fellow scientists, the researchers have been honestly acknowledging the limitations of their research. However,
the media doesn't understand that message. Columnist Ann Landers, for example, tells her readers that "homosexuals are born, not made." The media offers partial truths because the scientific realityis simply too unexciting to make the evening news; too complex for mass consumption; and furthermore, not fully and accurately understood by reporters.
Is There a "Gay Gene"? <--- click