The Molecular Genetic Study of Sexual Orientation is an ongoing study of the genetic basis for homosexuality, a scientific inquiry into what gays and naturalists already know, but which religious leaders and social conservatives don’t necessarily want to hear: that a certain percentage of all animal forms of life are attracted sexually to members of their own gender, that it’s not a matter of conduct but rather an innate characteristic--and that while it may constitute a variation, it’s not a pathology.

As reported yesterday by the Chicago Tribune, the study’s goal is to analyze DNA from one thousand families that include gay male siblings and discover, possibly, the genetic basis for homosexuality.

The study recruits its volunteers at community events such as Chicago’s Halsted Street festival, which took place this weekend.

Research around the genetic and physiological basis for homosexuality frightens people on both sides of the debate over human sexuality. Religious and social conservatives insist that the gay "lifestyle" is a matter of choice, and therefore falls into the realm of sinful behavior. Definitive proof of a physiological basis for homosexuality could undercut that argument--to those who do not simply dismiss science out of hand, anyway.

On the other side of the question are gay activists and bioethicists, who wonder whether socially conservative policymakers might seize on scientific proof that homosexuality is genetic or a matter of hormone balances and neurology to promote doubtful "cures," or even demand pre-natal screening in order to cull gay children before birth.

But the scientific method relies on ensuring that the information at out disposal is complete and correct. What to do with that information is up to society at large.

"If there are genetic contributions to sexual orientation, they will not remain hidden forever," Timothy F. Murphy, a bioethicist associated with the study, said, adding, "the march of genetic science can’t be stopped."

Continued Murphy, "It’s not a question of whether we should or should not do this research, it’s that we make sure we’re prepared to protect people from insidious uses of this science."

There is a growing, if indirect, body of evidence to support the scientific view that homosexuality is an inborn characteristic for gay people, rather than a political or moral choice.

Autopsies and other anatomical studies done in recent decades on gay people have revealed tantalizing variances in neurological structures and other physiological differences; Time magazine recently ran a piece discussing a study that found that younger male siblings were significantly more likely to be gay than their older brothers.

And studies looking at twins (both fraternal and identical) keep resulting in strong indications that sexual orientation may be a matter both or nature and of nurture. Identical twins are especially interesting to scientists, because they are natural clones, sharing a 100% identical genetic makeup; fraternal twins, who result from two ova being fertilized at the same time, are, like other siblings, only 50% genetically identical.

Identical twins consistently demonstrate a higher incidence in which both siblings are gay, as opposed to fraternal twins.

In most situations, though, siblings of all sorts share the same family environment.

Starting in the early 1990s, scientists began looking to genetics to explain the mounting evidence that homosexuality is a heritable characteristic. The main focus of the such studies is to examine the genetic sequences of siblings--gay and straight--to try and zero in on any telltale specific genetic sequence or set of sequences that might be identified as related to homosexuality.

One small study in 1993, by geneticist Dean Hamer, suggested that a genetic sequence on the X chromosomes of gay men was consistently found, but later studies were unable to confirm this. If the theory had been confirmed, it would have suggested that in at least some instances a tendency toward homosexuality is communicated to children through the mother’s genes.

One problematic feature of Hamer’s research was the small size of his genetic sample.

"In complex gene scenarios, people figured out that you need a larger sample size in order to get reasonable statistical power," according to the leader of the current study, Dr. Alan Sanders, who is also a Chicago-area psychiatrist.

Sanders’ study, with its goal of samples from 1,000 families, would be ten times larger than similar studies. As of now, the study has accumulated just over half its target number of samples: DNA samples and survey information from 600 sets of brothers.

Sanders’ project began in 2001, and has relied on gay Pride and other festivals, and gay publications, to bring in volunteers.

A study of this sort--called a "linkage study" because it seeks a genetic "link" to a given characteristic--starts by looking for an area in the genetic sequence that is found consistently in individuals who exhibit that characteristic. Only then would individual physiological traits be sought after.

Said Sanders, "One of the advantages of linkage studies is that we don’t have to know those things ahead of time."

Sanders continued, "It’s a big advantage here because we don’t know about the biology of sexual orientation yet, so we can find the genes first and then study the biology."

The human genome is vast; although its literally billions of base-pair sequences have been mapped, there are large gaps in understanding which sequences are responsible for regulating which facets of an individual’s development. Any so-call "gay gene" might regulated a person’s hormones, brain development, or other physiological system.

"The genes would probably be doing their work by affecting sexual differentiation of the brain during prenatal life," theorized J. Michael Bailey, a professor of psychology with Northwestern University who is associated with Sanders’ study.

"But what scientists are increasingly appreciating is that genes can affect a trait in ways you could never have guessed," added Bailey.

Already, some religious leaders--such as the leader of Exodus, a religious "ex-gay" organization--are responding to the mass of circumstantial evidence by moderating their tone and their message.

Other religious and socially conservative voices cling hard to the drumbeat message that homosexuality is a "lifestyle" voluntarily chosen by its "practitioners." An early, and enduring, message from religious conservatives has been that gays "recruit" children as an alternative means to sexual reproduction.

But gays and lesbians themselves say that they knew, even in childhood, that they were "different." Indeed, according to the Gay, Lesbian, and Straight Education Network (GLSEN), a national organization that seeks to provide educational tools about homosexuality to schools, middle and high schools are hotbeds of anti-gay harassment, indicating a vital awareness of the variability of human sexuality at a youthful age.

Said Sanders, "A lot of times people we talk to see this research as providing evidence for something they may already [have] had a notion for: that sexual orientation is influenced by pretty early events out of their control."

Social conservatives have begun attacking comprehensive sex education in schools as a front for a "pro-gay agenda." Indeed, if the science that suggests a biological basis for homosexuality is confirmed by rigorously tested genetic proof, ideology may yet give way, socially and politically, to objective factuality.

According to Sanders, as the body of evidence grows, and public awareness that likely root causes of homosexuality are biological increases, acceptance of the GLBT community also grows.

A Gallup poll from May tends to support Sanders’ opinion, showing that forty-two percent of Americans believe that a person’s sexuality is a matter of biology rather than choice. That’s the highest rate in 30 years of polls.

Chicago resident Jason Palmer, a participant in the study, expressed to the Tribune the hope that scientific fact would temper the hostility some religious sects harbor toward gays and lesbians.

Said Palmer, "Our strongest opponents are the religious right, many of whom feel that God does not make mistakes."

Continued Palmer, "So if it’s a genetic factor and proven, perhaps many of them will find an acceptance for homosexuals."

Irrefutable scientific proof could also have the opposite effect: it could be used by the religious and the socially conservative to mount renewed arguments that homosexuality is a pathology, and prompt demands for in-utero screening and high-tech "cures" or "treatments."

Philosophy professor Udo Schuklenk expressed concern that, "If you do research on any human behaviors that would allow us either to treat the behavior or to prevent it altogether by prenatal testing, you have got to ask yourself serious questions about societal context in which this type of research takes place."

Schuklenk, a professor at Queen’s university in Ontario, took a more global view of the potential for abuse of such findings than did Sanders, who doubted that such medical interventions would be workable, or that society at large would desire them.

Said Schuklenk, "I understand why U.S. gays want to know why gay people are gay and understand where they are coming from--there are legal reasons, and the agenda is progressive within the context of the U.S."

However, Schuklenk continued, "What worries me is that they show a complete disregard of repercussions of research on the international scale, for gay people in societies where civil rights are not as well-protected."

But, said Bailey, "People who say that, ’We shouldn’t know X because knowing X is dangerous,’ to me those are the dangerous people."

Added Bailey, "They have provided no good evidence that knowing things is risky; ignorance is what messes us up."

Bailey also noted that the results from the study have the potential to address broader scientific questions about gender and sexuality than the relatively narrow topic of homosexuality.

"Knowing what causes sexual orientation is important scientifically," said Bailey.

"It’s an important aspect of who we are, and [understanding it] will provide knowledge about the development of gender, how men and women differ from each other."

New Study Seeks Genetic Basis for Gays and Lesbians :: EDGE Boston

Once again, this is a matter of science simply catching up to -- or confirming -- what we already knew all along.

Of COURSE there are biological/medical aspects to homosexuality. How could there NOT be?

It sometimes amuses me the lenghts we'll go to in order to "discover" things that are pretty much self-evident.

I think they've already proven that the answer isn't in the genetics though. I think they are barking up the wrong tree. It's just that there can't be any research on anything that can be viewed negative toward homosexuality. Such as any study that might show homosexuality is a genetic malfunction. If anything, the twins study might show that to be the case.

Well, I agree that homosexuality has become/is becoming "That which thou shalt not say anything negative about" in our society.

I'm not holding my breath for any truely objective research into it any time soon.

But Mr. fxashun, there are already conditions such as hermaphrotism. if the body can be born with both types of sexual organs why can it not be born with the wiring to be attracted to both sexes?

I think when it all comes out in the wash, it will be something very much along those lines. The real debate then will be whether it's a disorder.

IMO, it could be classified as such. For one thing, like many disorders, it occurs along a continum. Take depression, for example. Some people might suffer from it mildly, and have a hard time getting motivated or cry easily.. while others might have it so badly, they can't hardly get out of bed, and are under near constant threat of suicide.

Likewise, some people are only "a little" attracted to the same sex. Others might be 50/50 true-blue bisexuals... others might be only "a little" attracted to the opposite sex.. and still others are attracted ONLY to their own gender.

I agree. Transgenerism and hermaphroditism are both sexual orientation defects. If we consider those "disordered" what gave homosexuality the edge to be considered a "normal" variation? When it is obviously not.

I agree. There was a study that showed a high percentage of men had a degree of attraction to pedo material.
A survey by Kent State University 1995 (LORI L. OLIVER, GORDON C NAGAYAMA, RICHARD HIRSCHMAN) was conducted on a sample of 80 normal male volunteers using the "penile plethysmograph". The team carried out hundreds of tests exposing them to nude female adult and child (<12 years) images.

• Over 1/4 (32.5% in fact) of the subjects exhibited penile arousal to pedophilic stimuli that equalled or exceeded arousal to adult stimuli.
• 95% exhibited arousal to the female adult images (4 exhibited no arousal)
• 88.7% exhibited arousal to the female child images. (9 exhibited no arousal)
• 76.3% exhibited arousal to the contrasting images (Ten subjects exhibited no sexual arousal )

I think humans have very screwed up sexual programming in general and males even more so.

but we do not deny marriage to hermaphrodites, do we?