‘The Biggest Myth Related to Sex Is Sexual Orientation’

BRITISH-BORN neuroscientist and writer Simon LeVay is best-known for his research on the difference between the brains of gay and straight men. LeVay, 80, previously worked at the Harvard Medical School and the Salk Institute for Biological Studies but is now retired. He has written several books, including a major textbook on human sexuality. His latest work, Attraction, Love, Sex: The Inside Story (Bloomsbury, 296 pages; ₹599) is a delightful account of human sexual behaviour. LeVay wanted to delve into the “mysteries of sex”.

The book opens with the most basic question: why have sex at all? Why not reproduce asexually, for instance, without all the bother of finding a mate? There might be some answers from other parts of the animal kingdom, and LeVay takes us through field studies on different creatures. In other places he shows us how abstract concepts like love and attraction can be connected to things we least expect. For instance, some studies suggest that attractiveness is linked to Body Mass Index (BMI), or that women’s
attraction to men can be influenced by their phase of the menstrual cycle. In every chapter—with the briefest of titles such as, ‘Arousal’, ‘Love’, ‘Porn’ etc— LeVay sifts the available evidence, critically engaging with the studies he presents. Not all of it comes from biology; some is drawn from happiness studies, social science surveys and large data sets. So while biology is at the heart of his book, LeVay takes a broader, more multi-disciplinary approach. Further, he does not hesitate to wade into controversial terrain when dealing with subjects like rape and paedophilia. He even makes a case for treating non-offending paedophiles less harshly. He argues that if they do not act on their impulses they should not be stigmatised as their sexual orientation is not in their control. Each of the 11 chapters deals with a single question or concept, right from ‘Attraction’ to ‘Having Sex’. In the final analysis, there may be no complete answers to love and sex and why human beings do what they do, but the journey towards seeking answers might be valuable for its own sake. The strength in LeVay’s writing is its clarity—he unpacks romantic concepts with scientific tweezers, and brings a levity to the enterprise, without sacrificing any of the rigour of a researcher. He spoke from his home in West Hollywood, California. Excerpts:

Why should we look at sex from a neuroscientific point of view?

First of all, understanding human nature is a very valuable thing. Without even worrying about its benefits. But in addition, there are prejudices out there that are harmful. And science sometimes can help resolve those prejudices. So this kind of approach to sexuality is useful in that sense.

What are the biggest misunderstandings or myths related to sex?

One is sexual orientation. There’s a lot of controversy about same sex-marriage, and even whether same-sex behaviour should be legal or not. Oftentimes, the prejudices that people have, with regard to sexual orientation, are things like, it’s a choice people make, a bad choice, people become gay because they’ve been molested when they were children. There’s a lot of false ideas that people have about homosexuality.

You write of the pleasure aspect of sex. How unique is that to humans? And why is pleasure a part of it?

It’s certainly not restricted to humans. In some close primate relatives such as bonobos, we see that sexual contacts are pleasurable. And that pleasure has a use. It encourages sexual behaviour just in terms of reproduction, it’s an important stimulus. But in addition, perhaps even more so in humans, it has a value in terms of cementing relationships, enabling interpersonal bonding, which is important for social stability, child rearing, family cohesion.

You look at dating and relationships. So how do people decide who they end up with?

Most studies say people are attracted to people who are like themselves. If you look at couples, there’s a lot of similarities between them in age, race, personality and so on. I think that’s misleading, because people tend to meet people who are like themselves, because they’re in college, so they meet people of college-age, and they tend to meet people of the same race, because that’s who their social circle is. It doesn’t mean that they are specifically attracted to people like themselves. It doesn’t mean those types of relationships are particularly beneficial. I think it’s actually the opposite. Maybe because of my own experience. I’m in a relationship with a guy who’s extremely different from me. He grew up in Gujarat, in a small village, he’s much younger than me. He is very outgoing, I’m much more withdrawn and introverted. If you can survive the differences, I think they are very beneficial in terms of providing something that enriches the relationship. So I say, go for people who are different from yourself.

You dedicate a whole chapter to love. How can love be studied scientifically?

I focused on voles, mouse-like rodents, which have been studied in great detail by neuroscientists. There are two species of voles. The prairie voles form lifelong pair bonds, and act like they love each other. They really are very intimate with each other. There is another species which does not. They aren’t interested in pair bonds. They don’t mate for life. What’s been shown by looking at these two different species is that there are really specific systems in the brain that seem involved in pair bonding, particularly involving chemicals like oxytocin, vasopressin, dopamine. Their actions in the brain seem to be closely correlated with forming intimate relationships and maintaining intimate relationships over time. It’s been shown both in voles and in humans, that there are certain genetic differences between individuals whereby some individuals are more disposed to maintaining stable relationships and others more interested in relationships outside the pair bond. These genetic differences contribute to why some people are more promiscuous than others. So there is a biological underpinning to what we call loving relationships.

You write about attraction. There’s a biological component, but there’s also a cultural component?

Some aspects of attraction really seem to be hardwired and built in. Others are much more flexible, and culture dependent. One aspect of the latter is the influence of Body Mass Index, in other words, how skinny or how fat someone is. Particularly when men view women. In some societies, particularly where food is in short supply it’s difficult to maintain a high BMI; in such societies, men seem to be more strongly attracted to heavier-set women. Whereas in societies where there’s plenty of food, attraction seems to switch more towards thinner women.

Can you explain the biology behind same-sex attraction?

There are genetic influences on sexual orientation in both sexes. It’s not the whole story, but a significant part of the story. Scientists who have analysed the genomes of large numbers of men and women, some of whom were gay, or bisexual, some of whom are heterosexual have reported that there are a number of locations in the genome, where there are genes that probably contribute… Hormonal experiences before birth seem to be playing an important role. The levels and timing of sex hormones, such as testosterone, that are circulating in the blood of foetuses, influences the sexual differentiation of the brain in such a way as to influence the likelihood that this foetus when it’s ultimately grown up will experience same-sex or opposite-sex attraction. It’s possible that environment also plays a role, but we really have no direct evidence for that.

But same-sex attraction is also different in men and women?

If you look at the distribution of sexual orientations in men and women there is quite a significant difference in that, among men who are not heterosexual, most are exclusively homosexual. It’s a kind of U-shaped curve, with lots of heterosexual men, some homosexual men, and not so many bisexual men. There are definitely bisexual men, but their numbers are quite low. With women, you get a very different sort of curve with lots of heterosexual women, quite a lot of bisexual women, and relatively few exclusively lesbian women. The distribution is much more across the whole scale rather than focused at one end or the other. We don’t know exactly what the reason for that is.

Can you talk about your own research from 1991 on gay and straight men’s brains?

First of all, I’m gay myself. So it’s a topic I’ve always been interested in. In addition, in the late 1980s, there was research coming out of the University of California, Los Angeles, reporting that there was a region of the brain called the hypothalamus, which is clearly involved in directing our sexual desires towards one sex or the other. And that this region includes a tiny region within the hypothalamus that is typically larger in males than in females. I looked at whether this region would be different between gay and straight men, and I found that it was typically smaller in gay men than in heterosexual men. Since that time, there have been many other studies of the brain reporting on various other differences in brain structure and brain function between gay and straight men, between lesbian and heterosexual women.

What kind of reactions did that research attract?

There was a lot of media attention. The responses were mixed. I think many gay people liked my research, because they felt that it validated something that they had always believed about themselves. That their sexuality was a deep part of their nature they were born with, and not merely a pattern of behaviour that they had chosen to adopt. However, there are some gay people who thought this kind of research is dangerous, because it might be interpreted as showing there’s something wrong with the brains of gay people. Perhaps we should try and fix that, develop a method to make that part of the hypothalamus bigger, by adding cells to it or by genetic manipulation and examine foetuses and see whether the foetus is more likely to become gay or straight. That’s all science fiction, not something at all possible to do right now. But in the future, there might be some ability to do that kind of thing. So there is a risk involved in these biological approaches. The way I see it, we shouldn’t deal with these risks by simply banning the science or stopping these investigations. We should try and create a world where parents would feel blessed to have a gay child.

Is there any consensus on whether people have a biological predisposition to rape and do you see rape in other species?

Forcible copulation is seen in some other species. In orangutans, which are primates very closely related to humans, some males do engage in forcible sex with females. This kind of behaviour can be seen in some insects. So yes, there’s a tendency to have forcible sex throughout much of the animal kingdom. Now, what does that mean for humans? I would emphasise, not for a moment, does the existence of rape in other species justify rape in humans. But it may help us to understand it, and that might be important for helping to prevent it. Some people will say that human rape is driven not by sex, but by hatred of women. When some feminists have said rape is not sexual I have to disagree a little bit. I think it’s sexually driven, but also permitted by an environment which degrades women.

Subjects like rape, sexuality and paedophilia, can be emotive, even controversial. How do you research such subjects in an environment where something can flare up?

It’s not so difficult for me because I’m retired from academia. I no longer have a position that I can be fired from. For people who are in academia they have to be extremely careful. There have been people fired from their jobs for which I consider not good reasons, because they talk about very sensitive topics.

Isn’t that inhibiting for science?

I think it is. Academia should be about free exploration of ideas. Unfortunately, in some aspects of human sexuality, that’s not true. It’s not true in America today, for discussion of some aspects of transgender development, it’s not true for looking at paedophilia. So universities are under a lot of different
pressures. And these pressures can sometimes inhibit people’s ability to conduct scientific investigations.

Are there any biological differences between the brains of transgender and cisgender people?

There are reports that there are differences in brain organisation between transgender and cisgender people. Transgender people tend to have brain organisation that is intermediate, between male-typical and female-typical. There are some people who maintain there are no differences between the brains of males and females. I think that’s wrong. There are differences that have been now established. According to one recent study, these features are intermediate in transgender people, between what you typically see in men and what you typically see in women.

What are these typical differences between male and female brains?

Perhaps the biggest difference is in the brain region that I studied: the hypothalamus. It’s called INAH3. This is a region of the brain that is known to be different between males and females in all mammals. And it’s clearly involved in directing sexual behaviour. But there are also more general differences in the cerebral cortex, in regions of the brain that may be related, for example, to spatial behaviour. Things like navigating, where, on average, men tend to score better than women.