Sexual orientation is 100% determined in the womb – neurobiologist
They say a leopard never changes its spots – which is equally applicable humans. So who is really in charge of my life – me or my brain? Are we one and the same? We talked about this with Dick Swaab, professor of neurobiology at the University of Amsterdam.
Sophie Shevardnadze: Professor Swaab, it's really good to have you on our program. So we have lots to discuss. You said that any basic trait of a person such as sexual identity, predisposition to something is actually decided in mother's womb when you’re formed, when your brain is formed within the womb. A lot of other neuroscientists would argue with you because they're saying what we are is our genes plus the upbringing. But in your case, you're saying it's not nature versus nurture, it's just nature...
Dick Swaab: No, I have never said that. And I think that the distinction between nature and nurture is nonsense because, from the very beginning, it's an interaction between the two. So it's nature interaction with nurture, but the nurture already starts at the moment of conception. So it's the environment in the womb that is also very important. It's not only after birth that you can influence the nature. And that means that already in the womb, the structure of the brain is decided to some extent and some functions are programmed for the rest of your life in the womb.
SS: When you say to some extent to what extent, like if you have a percentage?
DS: Well, it depends on the function. So if you look to sexual orientation and gender identity 100 per cent is determined in the womb.
DS: Yeah. Language is determined for 100 per cent outside the womb from birth onwards are growing up in an environment that is shaping your brain for a certain language. If a Chinese child is brought up as a baby here in the West, then it gets a Dutch brain for language. But other things are decided already early. So it depends on what functions you're talking about.
SS: But the sexual orientation, because there's like a very important thing that you're pointing out, a lot of people would say sexual orientation also depends on where you spend your youth or the teenage years. Like, a lot of adult men that I met, they say, well, we went to the boys school. And that's how this thing happened. Others say, yeah, we were born this way. But when you say that it's predetermined in the womb, what exactly happens in that brain when you know that you're straight or you're gay or you're transgender in the future? How does that determine? How do you know?
DS: So, let's say, homosexuality is 50 per cent determined by your genes and 50 per cent, by the way, that nerve cells make contacts. It's called self-organization. And it also means that if you have the same genes because you are part of an identical twin and one of them is homosexual, then the chance that the other one will be homosexual is not a hundred per cent. It's 80 per cent. So it is an interaction between all the aspects that are important for brain development on the basis of the genes that you get from your parents. And it doesn't mean that your parents should be homosexual in order to become homosexual. It can be that the genetic background was there. It increases the chance that you become homosexual, but it's not determining it 100 per cent. The rest is the developmental process in the womb.
SS: So if it's a genetic thing, you know how right now we can test the embryos for whatever it is genetically, whether it's a disease or predisposition. So in that early stage, can you actually tell if your child is going to be homosexual, then you bring him up in a certain way?
DS: No, I already said this is 50 per cent genetic and it does not mean that if you have the genetic background, that you will become homosexual. So it all depends on what is happening from conception and onwards. And in addition, it's not one gene. So there are diseases like Huntington, which you can determine in the fetus because it’s one thing and you can tell this child will at the age of 35 get Huntington's disease. But our sexual orientation is not determined by one single gene. It's a whole complex of genes and it means that you cannot determine that in the womb.
SS: OK, but let's say there is a genetic predisposition to homosexuality. And then we don't know that as parents and the child is born and we bring him up as a straight person. Does that make my child a happier person or a less happy person? Because I didn't really follow what he was genetically programmed for, because you were saying also in your book that, you know, if we followed our true nature, which is like what our brain programmed us to be, we would be much happier.
SS: So how do we do that? And not even just for homosexuality, but actually for anything else. Like if I'm programmed to be a great pianist, but then I decide to be a physician, you know, and then I'm not as happy. I knew all my life I wanted to be a dancer, and my father said no. And I know that I would be a happier person because my brain programmed me to be a dancer. How do you know that from the beginning?
DS: Do you have children?
SS: Not yet. That's why I'm asking you so many questions because I want them to be happy.
DS: So you still believe that you can guide your children in a certain direction. I think what you should do is offer them the possibilities and see what they like to do. They will tell you by their interest what they really like. And when they really like something they will become very good in it because they can put a lot of time in it. And it's not that you push your child into a certain direction and he will do it. Well, if he does it, he can be very unhappy. And the same holds, of course, for sexual orientation. The idea that you can change a person from homosexual into heterosexual is nonsense. And there are still farms in the United States where people try to do that. They can stay depending on how much they pay for six weeks or six months. And the only result is that there are more suicides because you cannot change the sexual orientation of a person.
SS: Is something like transgender, when people want to change their gender, is also predetermined in your mother's womb?
DS: Yeah. And also for me, being male or female, feeling that you are a male or female, that's gender identity. It's very well said that it's determined before birth and it only becomes overt during early development. The youngest kid I saw was two years of age that really was convinced that he was born in the wrong body. And now it's a beautiful woman. Well, again, parents don't encourage children to become transsexual. It's a disaster for the family. So they do anything you can imagine in order to stop it, but you can't change it.
SS: But I think the big question here is… Because I've spoken to many people from America who were very split about whether their child should undergo the therapy of changing gender or not. Like, for instance, father says no. Mother says yes. And then the child behaves very differently with father, he's a boy. And then with mother, because she's convinced that he should be a girl, he behaves like a girl. And I'm thinking a child psychic is so fragile, you know, like I wanted to be an elf when I was 5.
DS: And they didn’t change you into an elf.
SS: Yeah, should my parents have listened to me and, you know, somehow transform me into an elf?
DS: But that's also why we don't take any irreversible measure before the age of 18. Here in the Netherlands, when a boy is convinced that he wants to change into a girl, it's important that you don't wait until 18 when he is going to become 2 meters big boy and then try to make an attractive girl out of that. What we do here is postpone puberty until the age of 18. And before that, you can give female hormones. They can dress as a girl, they can live as a girl and have the whole network that is adapted to that around them. And then when they are still convinced at the age of 18, then they can be operated. So it's not something to hurry.
SS: So that's what I’m saying because in America, I think, in some states they start this really early when kids are like 6 and 7 and 10. And I mean, how can they possibly really know what they want to be at that age?
DS: Yeah. But on the other hand, if a child knows it from an early age onwards and there are very good movies from the Netherlands about that also and they tell it in primary school, the parents tell the whole class what's happening, then the children, they don't mind. The next swimming lesson, they go as the other sex and they accept it.
SS: So you think it's about the environment? And if from the very beginning you're saying it's OK, you can be whatever you want then it's easier for children to actually choose the path they want to choose in the future?
DS: So if you look at the results of the sex change in the Netherlands, you can say that 98 per cent of the people that change sex are happy as a result.
SS: Ok, so that’s statistics?
DS: Yeah. And if you then look into the problems of the rest 2 per cent, then the problems are the parents, the jobs they lost, the environment, friends, you call it. So it's the environment that gives the problems. It's not the fact that they decided to change sex. Of course, you should exclude some people that have, because of brain disease sometimes, the idea that they want to change sex. So people who are schizophrenic or people who have a bipolar disorder, they have periods in which they want to change sex. But if this group is excluded then you cannot expect problems.
SS: So your book ‘We Are Our Brains’ implies that actually our personalities are defined by the structure of our brain, what we're talking about right now. How much of that can be changed when we're born and growing up? For instance, if I'm predisposed to manic depression from the very beginning, from my mother's womb, can I reverse that completely with meditation, really good psychotherapy etc. and become completely healthy and get rid of that tendency in me?
DS: Well, there's no scientific evidence that you can influence manic depression or schizophrenia by this type of environmental help. What is important is that you are not exposed to very stressful conditions because during stress the disease is becoming worse. But you cannot get rid of the disease by environmental therapies.
SS: OK, let's not talk that extreme. If I'm just prone to depression, you know, I'm a melancholic person or I'm an angry person and I'm prone to anger, can I change that in me completely?
DS: No. You have the vulnerability and you keep the vulnerability. So you cannot change that completely. But what you can do is — know about the circumstances that give you problems, know about the stressful circumstances, know about the personal circumstances that give you extra problems, and then better deal with your vulnerability, but you keep the vulnerability. And that's also the reason that people with vulnerability for depression, when something in the environment is happening that makes most people angry or sad, they just go into a depression. And you can treat the depression, you can come out of the depression, but you keep the vulnerability and next time it's happening again. So it comes back. And that means that a psychologist or psychiatrist should be modest in what they can accomplish, they can help people deal better with the weak points. But the weak points stay.
SS: When you're saying, you know, you should just realize which situations bring this vulnerability up in you and then sort of try to control it, does it mean that only people with big intellect can control these vulnerabilities? For instance, John Nash, a lot of people would argue that, you know, he learned how to control his schizophrenia with his intellect towards the end of his life...
DS: He didn't control it. Did you see the movie?
SS: ‘Beautiful Mind’? Yes, I did.
DS: So he learned how to deal with it. So the hallucinations still came and he could not make a distinction between hallucinations and the ideas he got, the professional ideas, because hallucinations are also coming as if they are coming from the outside world and they are real. And so he learned how to deal with it. And he is an exception in a sense that most schizophrenic people are not capable of being intellectually so strong, of course. He is a Nobel laureate. But in fact, he is also showing that even if you have a high IQ, you cannot prevent the hallucinations to come.
SS: But you can deal with it without being harmless to yourself and the environment?
DS: But that doesn't mean that your schizophrenia stops.
SS: OK. You also wrote in your book that, for instance, a violinist has a bigger part of a brain which is responsible for his left fingers. And you know, that's the way he's born.
SS: OK. So it develops as we play the violin? So that's where I want to know. It's first the action and then the brain adjusts to the action or it's the brain and then the action adjusts to it. Which one is it?
DS: I think you should first have the talent to become a good violin player and then you should have a lot of practice and the two together give the changes in the brain that ultimately make you a top violinist.
SS: Is talent also in the brain? Is it born in the brain?
DS: Yes. And you can also see that there are children who at the age of 5-6 are very good piano players and they have a lot of pleasure in it. And because it gives them pleasure, they like to practice and because they practice a lot and they get more and more of a distance from the rest of the population, they become better and better. So it's an interaction, but you should have a basis for it. So as somebody who hates to play the piano and somebody who doesn't have the talent, well, forget it.
SS: Well, no, but I know a lot of people who don't have the talent, but they love it so much that they become better pianists than those who have talent. What about that?
DS: Well, I would like to see a scientific study on that. I don't believe you.
SS: OK. So if we can actually figure out by a person's brain what kind of predispositions he has and you're saying we can...
DS: Well, I don't say that they can by studying the brain, we can do that by studying the behaviour.
SS: Just behaviour? Because there's no such thing. Because I was thinking before coming here, if the professor tells me that there's this scan where you can scan a baby's brain in a mother's womb and figure out if he's predisposed to be a murderer or a genius mathematician, then you can really organize the society in the future. There's no such thing?
DS: No, it’s not possible.
SS: Thank God. Because that would be worse than the scary stories about artificial intelligence taking over humanity and all of that, right?
DS: Yeah. No, a brain scan can only show abnormalities that will prevent somebody to have a normal life. And of course, then you can decide for an abortion. But, uh, it's only abnormalities and not talents or the character of a child, something like that. It's not possible.
SS: You know, when I go to a gym, for instance, I tell my trainer I want to have bigger biceps, he gives me exercise and then, you know, the shape changes. Can you do something similar with brain and feelings? For instance, can I teach my brain how to love or to be compassionate if I don't have it in me? Can you exercise your brain like you exercise your biceps?
DS: Well, to love, you need empathy. And there are people born without empathy. They go straight to their aim. They don't mind what they do to other people. And we call them psychopaths. And those people are trained for empathy without any success so far. If you don't have empathy from the beginning, you cannot give a person empathy.
SS: Tell me scientifically what determines in the brain whether I have empathy or not? What kind of connections in the neurons? Like, what is it?
DS: Well, those are neurons. We call them mirror neurons. They mirror what the environment is doing. So if a mother is making some movements and the child is mimicking, then the brain learns how to make that movement. But if the mother is making that movement and the child sees it, it's already enough to make in the brain that movement and train the circuits that are necessary for it. The same holds for emotions. If you have the capability for emotions, for empathy and you have an interaction and you see that somebody you love is sad or happy, then you also mimic those emotions and the brain learns how to deal with that. But if you don't have it by inborn differences, then it's impossible to give it.
SS: How do you explain sometimes the fact that a child is born in despicable conditions, like, from crackhead parents, violent parents, goes from one foster family to another where he's abused, and then somehow that person who we think is gonna be just like the parents, a criminal or a drug addict becomes one of the best humans in the world. How do you explain that?
DS: Well, you just tell me how important early development and genetic background is and that the environment is not so important. If you have the capabilities, if you have the brain from early onwards, that makes you a special person, Paganini, for instance, he was hit by his father if he didn’t study enough because his father wanted to use his talent to earn money. And finally, he escaped from the family, I think at the age of 16 or so, very early, and he was travelling to Europe. He was also involved in criminal activities like his father, in gambling etc. He even was probably involved in killing a person. But he made beautiful music. That was his talent and the talent was coming from his father, who also was a musician.
SS: Well, Wagner was a terrible human being but he made beautiful music as we all know.
DS: Well, we can discuss that.
SS: You disagree with that, right? OK, there was this study where — I don't remember what it was called — it was a huge study and I was going through it when I was preparing for you. It actually said that you could tell by the size of our amygdala our political leanings. For instance, if the amygdala was bigger, there's a 99 per cent chance that you're a conservative and vice versa. How could you believe that?
DS: Well, all this is based on statistics and it gives you a chance that somebody is right- or left-wing. But for a person, it's not possible to predict if you are right- or left-wing depending on the amygdala. So it's only for a group.
SS: I don’t understand. What do you mean?
DS: Well, I’ll try to explain. If I say men are taller than women, there are quite a number of students here in the lab who are taller than I am. But still, for a group, I can say men are taller than women. That's statistics.
SS: It depends what nations you're talking about.
DS: No. Everywhere.
DS: Yes. For the whole group in the same environment, men are taller than women. But from the height of somebody, if I get only the height,1,85 meter, I cannot say whether it’s a man or a woman. So for a group, you can make predictions, but not for an individual.
SS: Ok, so it’s a really rough overall statistics. Is this what you’re saying?
DS: If you call it off, it’s statistics. And well, it's important to note that whatever property we are talking about, it has a variability, huge variability. That holds for everything, not only for a talent in some direction but for all our properties, and the variation was the basis of evolution. I think that evolution for our brain, for us has stopped. We can discuss that, but the variation is still there. And there are always people who are only in the extremes. And society doesn't like that, if you are in the extreme for a property. You should be in the middle, then everybody feels safe. But those people in the extremes can also contribute their special things.
SS: Professor Swaab, it's been a pleasure talking to you. Thank you very much for this interview and good luck with everything.
DS: Thank you.