There's No Such Thg as a 'Gay Gene,' Massive Study Conclus | Live Science

Contents:

• THE 'GAY GENE' IS A TOTAL MYTH, MASSIVE STUDY CONCLUS
• NEW TW STUDY: PEOPLE NOT BORN GAY
• THERE IS NO ‘GAY GENE.’ THERE IS NO ‘STRAIGHT GENE.’ SEXUALY IS JT PLEX, STUDY NFIRMS
• SCIENTISTS FD DNA DIFFERENC BETWEEN GAY MEN AND THEIR STRAIGHT TW BROTHERS
• LARGT STUDY OF GAY BROTHERS HOM ON 'GAY GEN'
• NO ‘GAY GENE’: MASSIVE STUDY HOM ON GEIC BASIS OF HUMAN SEXUALY
• GAY MEN TW STUDY
• SOME RANDOM THOUGHTS ON ‘GAY GENE’ STUDI

THE 'GAY GENE' IS A TOTAL MYTH, MASSIVE STUDY CONCLUS

In a study where scientists looked at the sexual aroal patterns of intil tws wh different sexuali—specifilly, where one was gay and the other was straight—they found that gay tws monstrated more genal aroal rponse to same-sex imag, whereas straight tws monstrated more aroal rponse to oppose-sex imag [2]. In theory, this means two people uld rry “gay gen, ” but both of them wouldn’t necsarily be gay pendg on certa environmental factors. Tw pairs which at least one tw is homosexual were soliced through announcements the gay prs and personal referrals om 1980 to the prent.

NEW TW STUDY: PEOPLE NOT BORN GAY

Two sets ntaed a pair of monozygotic tws nrdant for sexual orientatn wh the third triplet dizygotic and disrdant for homosexual orientatn. N help expla why someone is gay or straight, relig or not, bray or not, and even whether they're likely to velop gum disease, one psychologist broad-rangg geic effects first me to light a landmark study — Mnota Tw Fay Study — nducted om 1979 to 1999, which followed intil and aternal tws who were separated at an early age. Most of the more recent rearch on possible blogil origs of homosexualy has foced on the gree to which gen, along wh other prenatal factors such as hormon and epi-geics, may fluence the velopment of homosexualy.

The former approach of recg intil tws via advertisements gay and lbian publitns is now known to have a very strong “volunteer effect” that produced the appearance of relatively large geic effects (1). Neverthels, even wh the e of large tw registri, the number of intil tw pairs found wh homosexualy is often very small dividual studi, rultg a standard viatn that is greater than the lculated geic effect, meang that the rults are not statistilly different om zero. Whehead and Whehead (1) have prented and discsed, some tail, the and other problems herent tw studi of homosexualy and have prented reasons to expect that the geic fluence on, or ntributn to, homosexualy will eventually be agreed to be the 10%-15% range (i.

Another reason has to do wh the apparently predomant fluence of post-natal environmental factors on the velopment of homosexualy (10).

THERE IS NO ‘GAY GENE.’ THERE IS NO ‘STRAIGHT GENE.’ SEXUALY IS JT PLEX, STUDY NFIRMS

Schumm (9) found that children wh homosexual parents are 12-15 tim more likely than children of heterosexual parents to be homosexual as adults. This is the strongt environmental fluence ever reported for the velopment of homosexualy, and volv very close fay members, the parent-child relatnship.

The rults of a study by Kg and McDonald (8) illtrate how such a close, fay relatnship uld flate the lculated geic fluence on homosexualy  intil tw studi. They studied 46 tw pairs havg homosexualy prent one or both of the tws each pair and found that 54% of the tw pairs had discsed their sexual orientatn wh each other, 89% had “shared knowledge” of each other’s sexual orientatn, and 30% of the tw pairs had actually had sex wh each other. Bee intil tws intify so closely wh each other, and post-natal experienc – pecially close fay relatnships – strongly affect the velopment of homosexualy, seems plsible, if not likely, that a homosexual member of a tw pair would fluence the other member of that pair to embrace and explore homosexualy also, th flatg the apparent geic fluence reported intil tw studi.

That is to say, a signifint portn of what may appear, intil tw studi, to be a geic fluence on the velopment of homosexualy may turn out to be, stead, a post-natal, environmental fluence volvg shared knowledge of sexual orientatn and shared sexual experienc wh intil tw pairs. The “pair-wise nrdance” answers the simple qutn, “Where one tw of an intil pair is homosexual, what percentage of -tws is also homosexual”. The pair-wise nrdance valu dite that for every tw pair wh both members beg homosexual, there are 7 tw pairs wh only one homosexual member.

SCIENTISTS FD DNA DIFFERENC BETWEEN GAY MEN AND THEIR STRAIGHT TW BROTHERS

Now, pare this rult to the range of theoretilly possible out where no tw pairs would both be homosexual (= 0%) and where all tw pairs would both be homosexual (= 100%) and you n see, tuively, that a pair-wise nrdance of only 13. Therefore, on the basis of pair-wise nrdance intil tws, seems appropriate to nclu that there is, at the most, only a mor geic ntributn to the velopment of homosexualy, and that this relatively mor fluence n be overe (i. This timate of nrdance is necsary orr to e both intil and aternal tws a study to disentangle the relative ntributns to homosexualy of geic and non-geic (environmental) factors.

While pair-wise nrdance giv an tuive ditn of the geic fluence on homosexualy as exprsed intil tws, do not provi rmatn on what factors may provi the remag, non-geic fluence. In a meta-analysis, Whehead (6), g the rults om seven of the recent tw registry studi that were signed to reveal ntributns of both geic and non-geic factors to homosexualy, found that the mean ntributn of geics to male homosexualy was around 22%, and to female homosexualy, around 33%.

Furthermore, the non-shared, post-natal environmental ntributn to homosexualy is morate to strong, around 64%-78%, has a relatively small standard viatn and is nsistently around the same percentage (6), ditg that homosexualy is fluenced primarily by post-natal environmental factors and experienc that are not directly related to prenatal, blogil ntributns of any kd or batn. They ed a very large sample (9, 884) of tws om the Atralian Tw Registry, one of the largt sampl to date for tw studi of homosexualy. ) on the velopment of homosexualy adults is only weak-to-morate, is important to unrstand that all of the blogil theori bed n addrs only this weak-to- weakly morate amount of fluence, while ignorg the far more important post-natal fluenc (e.

LARGT STUDY OF GAY BROTHERS HOM ON 'GAY GEN'

Furthermore, tw studi clearly support the ference, based on rults obtaed through therapy and unselg (4, 5), that post-natal, environmental fluenc have a far greater role the velopment of homosexualy than do pre-natal, blogil fluenc. No dividual gene alone mak a person gay, lbian or bisexual; stead, thoands of gen likely fluence sexual orientatn, a massive new study of the genom of nearly half a ln people human societi and both sex, between 2% and 10% of people report engagg sex wh a member of the same sex, eher exclively or addn to sex wh a member of the oppose sex, the rearchers said. Related: 5 Myths About Gay People Debunked"Bee is a ntroversial topic, fundg has historilly been limed and recment of participants was difficult, " study -thor Fah Sathirapongsasuti, a senr scientist and putatnal blogist at the geic ttg pany 23andMe, told Live Science.

However, the fdg that there's no sgle gay gene do not mean that sexual orientatn is not geic or blogil, and is therefore a liftyle choice. Numbers of people who have changed towards exclive heterosexualy are greater than current numbers of bisexuals and homosexuals bed. Consir the followg and ask yourself this qutn: Why are scientists workg to overe the geic irregulari but not homosexualy which is geilly unter productive?

NO ‘GAY GENE’: MASSIVE STUDY HOM ON GEIC BASIS OF HUMAN SEXUALY

It is worth keepg md that this study only vers some typ of sexualy — gay, lbian and cis-straight — but don’t offer many sights to genr inty. Humans have tried to unrstand human sexualy for centuri — and geics rearchers joed the ay the early 1990s after a seri of studi on tws suggted homosexualy ran fai. “As a teenager tryg to unrstand myself and unrstand my sexualy, I looked at the ter for “the gay gene” and obvly me across Xq28, ” said Fah Sathirapongsasuti, a study -thor and senr scientist at 23andMe, which he joked once led him to believe he hered his gayns om his mother.

“We worried a lot about volunteer bias, ” said Bailey, whose rearch clus a wily publicized study on Xq28 and gay brothers om 2018. The rearchers had members of the same-sex muny review the study’s sign and language, and they adm that their termology and fns for gay, lbian and heterosexual do not reflect the full nature of the sexualy ntuum. “[Our study] unrsr an important role for the environment shapg human sexual behavr and perhaps most importantly there is no sgle gay gene but rather the ntributn of many small geic effects sttered across the genome, ” Neale said.

Ngun reported that studyg the geic material of 47 pairs of intil male tws, he has intified “epigeic marks” ne areas of the human genome that are strongly lked to male dividuals, said Ngun, the prence of the distct molecular marks n predict homosexualy wh an accuracy of close to 70%. Geicists suggt that together, the human genome and s epigenome reflect the teractn of nature and nurture -- both our fixed herance and our bodi’ flexible rpons to the world -- makg who we ’s study of tws don’t reveal how or when a male tak on the epigenomic marks that distguish him as homosexual.

GAY MEN TW STUDY

”To fd the epigenomic markers of male homosexualy, Ngun, a postdoctoral rearcher at UCLA’s Geffen School of Medice, bed through the geic material of 47 sets of intil male tws.

But the existence of tw pairs which one is homosexual and the other is not offers strong evince that somethg other than DNA alone fluenc sexual orientatn.

So they unleashed a mache learng algorhm on the data to search for regulari that distguished the epigenom of homosexual tw-pairs om tws which only one was ne pact regns sttered across the genome, they found patterns of epigenomic differenc that would allow a predictn far more accurate than a random gus of an dividual’s sexual orientatn, Ngun reported Thursday. McCarthy and other experts utned that the disvery of epigenomic marks suggtive of homosexualy is a far cry om fdg the of sexual distctive epigenomic marks observed by Ngun and his lleagu uld rult om some other blogil or liftyle factor mon to homosexual men but unrelated to their sexualy, said Universy of Utah geicist Christopher Gregg.

SOME RANDOM THOUGHTS ON ‘GAY GENE’ STUDI

But the existence of intil tw pairs which only one is homosexual “nclively suggt that gen don’t expla everythg, ” Bailey Ngun’s rearch needs to be replited larger studi of tws, advanc the fful procs of better unrstandg how — and when — a boy’s sexual orientatn velops, Bailey me on Twter @LATMelissaHealy and “like” Los Angel Tim Science & Health on rarely get ncer, now scientists thk they know whyThree rearchers w Nobel Prize chemistry for studi of DNA repairMars had a long-lastg seri of lak, NASA’s Cursy rover fds.

In some untri, such as Uganda, beg gay is still crimalised, and some relig groups believe that gay people n be “treated” to make them straight. Over the past five years, Sanrs has llected blood and saliva sampl om 409 pairs of gay brothers, cludg non-intil tws, om 384 fai.

Sanrs says he has already pleted the work for that next step: he has pared SNPs those specific regns gay and straight men to see if there are obv differenc the gene variants, and is now preparg the rults for publitn. “This study knocks another nail to the ff of the ‘chosen liftyle’ theory of homosexualy, ” says Simon LeVay, the nroscientist and wrer who, 1991, claimed to have found that a specific bra regn, wh the hypothalam, is smaller gay men.