Other Traits

Is homosexuality an inborn, unchangeable part of us or can people actually "convert"? I think it is just the way I am but my classmates and some family members think otherwise. How can I convince them that this really is the way I am supposed to be?

-A high school student from California

December 22, 2005

First off, almost all of the data shows that being gay is not a choice. Most people discover they are gay rather than choosing it. As such, it is very difficult to "convert" to heterosexuality. It requires going against who you are.

I have seen no reliable data on the conversion of homosexuals. Or on how well it works, how happy the recently "converted" are, how long they stay "converted", or any other statistics. There is some anecdotal data -- things like it worked for me, it can work for you. But nothing that would make it into a scientific journal.

Because of this, I can't evaluate the therapy scientifically. But even proponents say the success rate is pretty low -- it doesn't work that often.

One reason why conversion might be so difficult is that the brains of gays may be different from their straight counterparts. For example, a couple of studies have been done that show that the brains of gay people are different than those of straight people.

And that gay people respond to pheromones differently than straight people. This isn't surprising, sexual attraction resides in the brain. But where do these changes come from? Are they destined by genes, is it something in the environment or a combination of the two?

The best evidence points to the environment and genes both playing a role.

To try to sort out environment and genes, scientists often do a twin study. In a twin study, identical twins are compared to fraternal twins. If something happens more often in identical twins, then that something is influenced by genes.

How does a twin study show something runs in a family? Remember, identical twins have exactly the same genes. Fraternal twins share only as many genes as any brother or sister.

Because twins are born at the same time, the environment is as same as possible for them. So if something happens more often in identical than in fraternal twins, then it is most likely because they share the same genes.

A number of studies have looked at homosexuality in twins, all with similar results. For example, in one study, if one identical twin was gay, the other was also gay 50% of the time. If they were fraternal twins, they were both gay 22% of the time. And if one was adopted, the chances fell to 11%.

Now these numbers are from one study. Other studies have different percentages but the same trend -- identical twins are more likely to both be gay as compared to fraternal twins.

This strongly suggests that there is a genetic component -- there is something in their genes that makes them more likely to be gay. Genetics, though, isn't everything.

If it were, then identical twins would both be gay 100% of the time. And this clearly isn't the case.

And if it were all environment, then identical twins would both be gay as often as fraternal twins. Again, this isn't the situation.

So the interplay of environment and genes probably results in homosexuality. By environment, I don't just mean how someone is raised (although that is sometimes part of it). I mean the effect the environment can have on how the brain is hardwired very early on.

In the womb, things happen that can affect how we develop. A surge of hormones here, a viral infection there, and we are not the same as we would be without these environmental factors.

Handedness is an example of this. Some people have genes that make them more likely to be left-handed. Not all of these folks end up lefties, though.

Something else has to happen while they are developing. Scientists haven't pinpointed what this something is but it is the combination of genes and environment that makes someone left-handed.

Maybe something similar happens with gay people. And since the brain continues to develop after we're born, the environment can affect how our brain develops even after we are born.

The key here, though, is that this all affects how our brains are hardwired. It isn't a choice or something like that, a brain has been configured to be attracted to the same sex.

Is there any evidence of this happening? There is some evidence that increased steroids in the womb may increase the chances that a girl will be a lesbian. Some studies show that the more older brothers you have, the more likely it is for you to be gay. Also, gay people tend to be left handed much more often.

The animal evidence is also pretty strong that what happens in the womb can affect the eventual sexual orientation of the fetus. For example, exposure to differing amounts of testosterone or estrogen in the womb can affect whether an animal is hetero- or homosexual.

How would genes work in all of this? What genes would do is either make the fetus more or less sensitive to these hormones or, perhaps, affect how or whether the mother reacts.

So, for example, a surge of hormones may change one fetus' brain but not another's. Or the mother might respond to stress with more hormones causing a change whereas a different mother wouldn't release as much hormone.

Whatever the cause, it is very unlikely that just one gene will cause someone to be gay, at least in people. But it is a different story in the fruit fly.

As we talk about here, a single DNA mutation can turn a straight male fruit fly into a gay one. A similar mutation in a female fly makes her more interested in the girls than the boys.

As I said, though, it is pretty unlikely that anything so simple is happening in people. Something so complex most likely involves lots of genes.

So there you have it. Being gay is not being mentally ill (at least according to the American Psychiatric Association). There appear to be real changes in the brain that correlate with being gay. And from the twin studies, it looks like genes play a role.

So can you convert? There isn't any good data on this but most health professionals think that most homosexuals cannot. Whether or not you can convert is really only something you, not your family or friends, can decide.

By Dr. Barry Starr, Stanford University