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Are Genes Destiny?

Dean Hamer is Chief of Gene Structure and Regulation at the National Cancer Institute's Laboratory of Biochemistry. He's the co-author of "Living with Our Genes: Why They Matter More Than You Think" (Doubleday). The book is about Hamer's research looking at how specific genes are linked to our behavior, traits like anxiety, thrill-seeking, and homosexuality. (Interview by Marty Moss-Coane)

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Other segments from the episode on March 2, 1998

Fresh Air with Terry Gross, March 2, 1998: Interview with Neil Jacobson; Interview with Dean Hamer.

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Show: FRESH AIR
Date: MARCH 02, 1998
Time: 12:00
Tran: 030201np.217
Type: FEATURE
Head: When Men Batter Women
Sect: News; Domestic
Time: 12:06

MARTY MOSS-COANE, HOST: This is FRESH AIR. I'm Marty Moss-Coane, filling in for Terry Gross.

Until recent years, very little was known about domestic violence. It happened in secret and no one talked about it -- not the families involved nor the professionals who might be suspicious about a mysterious bruise or a broken bone. That has changed, spurred by legal cases, advocacy groups, physicians, researchers, and therapists who have uncovered the pervasiveness of the problem.

Dr. Neil Jacobson has been working with couples in abusive marriages to try to understand the dynamics of their relationship. Jacobson is a professor of clinical psychology at the University of Washington. He and his colleague John Gottman undertook a long-term study of 200 such couples. They observed their fights up close and monitored their heart rates and other physiological reactions.

The results are revealing, and included in their new book "When Men Batter Women."

NEIL JACOBSON, PROFESSOR OF CLINICAL PSYCHOLOGY, UNIVERSITY OF WASHINGTON, CO-AUTHOR, "WHEN MEN BATTER WOMEN: NEW INSIGHTS INTO ENDING ABUSIVE RELATIONSHIPS": We tried to look at the underbelly of domestic violence as directly as we possibly could, by bringing people into the laboratory and hooking them up to polygraphs and videotaping and coding their arguments. Of course, we didn't allow any violent altercations to occur in the laboratory, but we were there watching as they argued.

And -- and then we followed them over time to see when and under what conditions women would get out of abusive relationships, and we also looked to see if the violence ever stopped.

MOSS-COANE: Let's talk a little bit about the study that is the basis of this book. First of all, tell us what kinds of sensors you attached.

JACOBSON: We used the polygraph with the capability of collecting a lot of different kinds of physiological data so that we could look at various channels by which people get excited when they're arguing, and to try and distinguish between fear, sadness, anger, and some of the different emotional states that people can't really tell you about with any degree of objectivity because they distort the experience shortly after it occurred, because batterers often minimize and distort their experiences to make themselves look more favorable.

The heart rate doesn't lie. And that -- so we were able to, I think for the first time, understand what's going on at the physiological level during these arguments.

MOSS-COANE: So, you're looking at things like heart rate and blood flow and pulse and all the...

JACOBSON: Blood pressure, sweating, movement -- all of these things usually there is a typical response physiologically during an argument. When couples argue, they usually -- their heart rates go up; their blood pressure goes; they sweat; they get excited physiologically, and there is this overall arousal that occurs, which is common even among abusive couples and, as you know because you've read the book, we found this quite astonishing phenomenon among 20 percent of the batterers.

MOSS-COANE: Yeah, let me ask you about that. You found that with 20 percent of the batterers, and again this is looking at the sensory, physiological information that you got, that there was actually a decrease in their heart rate when they became aggressive in an argument.

What -- explain what that finding tells us.

JACOBSON: OK, well, it tell us -- it was probably the single most important discovery in the study. If you can try and imagine being in a relaxed state, and then starting to argue -- because we had everybody relax for two minutes...

MOSS-COANE: Right.

JACOBSON: ... prior to the beginning of the argument. And then we found that among 20 percent of the men, they actually got calmer as they became more aggressive at the behavioral level. So, they looked like they were candidates for a stroke or a heart attack...

MOSS-COANE: So they were yelling and screaming and pointing...

JACOBSON: ... yelling, screaming, pointing, interrupting, belligerent, contemptuous, domineering -- and meanwhile, we're talking about heart rates that are as low as 35 beats per minute and -- and we began to think of them as being sort of like cobras who get very calm as they're about to strike, and indeed there's literature to suggest that when people calm down during stress and conflict, the function of that calming is to focus your attention. So, why would they want to focus their attention? Well, to maximize the impact of the aggression.

So, we have a group of men who calm down when they get more aggressive in order to maximize the impact of their violence. These are men who are the most severely violent. They're the most emotionally abusive. They're the ones with long criminal histories going all the way back to adolescence and sometimes earlier. They're more -- they -- almost all of them are psychopaths. They usually have alcohol problems and they also have -- they're also addicted to illegal drugs. And the marriages are remarkably stable -- that is, they don't end very quickly.

MOSS-COANE: Looking at these two different kinds of batterers, what kind of impact did they have on the women -- on their wives? And in terms of their reaction to what he was doing?

JACOBSON: Well, the wives who were married to cobras were more -- much more frightened. They were much less-inclined to get out, even though the violence was more severe. They were more depressed and they -- their -- and they suppress their anger. Whereas the wives married to pit bulls were much more inclined to take their husbands on, and also much quicker to leave. So that by now, 1998, even though we met these people for the first time in 1990 or 1991, by now virtually all of the women married to pit bulls are out of those relationships, except in those rare instances when the violence actually stopped.

But the cobra wives are very, very reluctant to leave and most of that is because they're afraid to.

MOSS-COANE: We're talking to Neil Jacobson today. He's co-author of a new book. It's called "When Men Batter Woman: New Insights Into Ending Abusive Relationships."

For the sake of our discussion and from the research and work that you have done for 25 years, if we're talking about abusive relationships, are we talking about men battering women?

JACOBSON: If you're talking heterosexual relationships, married or unmarried, battering is almost exclusively something that men do to women and rarely something women do to men. Very, very occasionally, you find what we called in our book "Bonnie and Clyde couples," where the violence was -- the battering was truly mutual. But they're rare and they don't come into contact with therapists very often.

Now, you -- you know, you sometimes get couples where that's the way it looks on the surface, but if you probe deeply enough, you find out that the woman is the one who's battered. Of course, you also have gay and lesbian relationships where, indeed, men batter men and women batter women, but we're talking in our study about -- and in our book -- about heterosexual relationships.

MOSS-COANE: Let -- let me try another question on you, because this I have also heard, which is that the woman will goad him and taunt him and yell at him, and then he will finally hit her. How much of that have you observed?

JACOBSON: I've -- we observed the opposite. We observed -- I hope, again, our book puts an end to that myth. First of all, there's nothing that a woman can do to force a man to hit her, except to try to inflict bodily harm on him. So no matter what she were to do to him verbally, that wouldn't be a justification for him using violence toward her, nor would it be the cause of the violence.

Men hit for reasons that have nothing to do with what women do. Now, our research support that empirically, so we now have proof that that's the case, but even thinking about it logically, you can't force someone to hit you. We had one example of a wife who said to her husband at a time when he was having trouble getting an erection: "you must be a fag, just like your father." So she was insulting him and insulting his father. Wasn't very nice.

He then punched her in the face and was -- and she called the police and he was arrested and charged with assault. He was guilty of assault despite the fact that what she said wasn't very nice. In fact, however, it's -- it's not typical for men to hit because women taunt. It's more common for men to hit for reasons that have nothing to do with anything the woman has done.

He walks in the door and he smacks her in the face. She hasn't done anything. Women are violent under very predictable conditions, like when someone is hitting them, they may defend themselves. Male violence is not predictable by anything that the woman does except withdrawing. When the woman withdraws while she's being beaten, that increases the likelihood that the beating will get worse.

MOSS-COANE: Increases the likelihood?

JACOBSON: Increases the likelihood.

MOSS-COANE: Why?

JACOBSON: So there's -- there's virtually -- because it annoys him and irritates him and angers him that she's trying to get away. He's not done beating her yet and she should stay and take her beating, according to the man.

But there's nothing that the woman can do to affect the likelihood that he will start hitting her, stop hitting her, hit her harder, or hit her softer except trying to get away, which will typically make the beating worse.

MOSS-COANE: What do you see as the relationship between physical abuse and emotional abuse? Does one naturally lead to the other?

JACOBSON: Well, most batterers, in fact virtually all batterers, are also emotionally abusive. And sometimes as time goes on, they become less physically abusive and more emotionally abusive because emotional abuse takes on the same controlling power that physical abuse has, and it's not against the law.

So it can look like the violence has stopped, but in fact the woman is under control as much as she was when she was being beaten, because the emotional abuse is a reminder that at any moment the physical abuse could resume.

MOSS-COANE: Dr. Neil Jacobson is our guest, and we're talking about his research on domestic violence. More after a short break.

This is FRESH AIR.

Neil Jacobson is our guest today, and we're talking about a book he has just co-authored. It's called When Men Batter Women: New Insights Into Ending Abusive Relationships.

Do people in abusive relationships fight about, argue about what everyone else does? They just express it differently? Or, are there things that they argue about that are distinctively different?

JACOBSON: Well, for the most part, they argue about everything all over the map, but I think -- I think there are a couple of distinctive arguments that batterers and battered women have, and there's a lot of arguing about sex, because batterers want sex whenever they want it, whether the woman wants it or not. And, that generates conflict. It's not the best -- it's not an aphrodisiac for women when men demand sex, whether women want it or not.

And then there's the issue of jealousy. Jealousy is a very common trait of batterers, and they're made jealous very easily. In fact, I would go so far as to say as that's one of my red flags. We have a chapter in the book where we talk about red flags -- things to stay away from in men. I'd almost like to be able to interview the men who former clients of mine meet, so I could check out these red flags.

But one of them is jealousy. If -- if the man will not allow his girl friend, wife, or partner to have friends of the opposite sex, or gets jealous about those friendships -- that's a very bad sign.

MOSS-COANE: Your study shows that there are different kinds of batterers, but what do you say to reports that others have said -- that batterers often act contrite and apologetic after a beating, and that there tends -- there can be a kind of honeymoon period and flowers and gifts and where he wants to make it up to her. Any evidence of that?

JACOBSON: I think that that phenomenon exists, but I think it's been vastly overstated in the early literature. People sort of glommed onto that finding when Lenore Walker (ph) first published it in the '70s. We found that to be the exception rather than the rule. Now, you do have some men who -- who don't feel right about the fact that they're batterers. And when I find a man like that, I think that wow, at least I've got someone here who may stop at some point, because it's not consistent with their value system.

That's the -- but that's the -- but the vast majority of men either fake the remorse or it's very, very short-lived and temporary.

MOSS-COANE: In talking about this relationship and in trying to answer the question why a woman stays in an abusive relationship, you found that many don't. And I think that's another myth that has endured -- that the women stay and take it.

JACOBSON: Yes. Yes, I have -- when I -- when I speak to groups of advocates for battered women, I suggest that when they get asked the question: why do women stay? The answer they should give is: they don't. Because that's really the truth. They leave.

It's just a question of how long it takes them to figure out a safe exit because they have to avoid getting killed. They'd like to avoid getting stalked. They'd preferably like not even to be beaten. And it's very difficult and sometimes takes years to orchestrate a safe escape.

And as we know, all too tragically, some of the escapes don't work.

MOSS-COANE: So you're saying that -- that a woman who stays doesn't -- it isn't -- doesn't mean she isn't planning and figuring out some kind of an escape plan.

JACOBSON: Exactly. And it's -- sometimes it takes years to come up with a -- it's not just a safety plan, it's also a plan for financial independence, because a lot of battered women are financially dependent on their husbands. And many of them have children, and they know they're not going to get child support from these men. So, how are they going to survive and how are their children going to survive without this financial support? So, they have to somehow develop this financial dependence without the batterer realizing that they're developing a safety plan.

It's not easy and it takes a while.

MOSS-COANE: You say that abuse over time can decrease, but it rarely stops. Are you saying that in most of these relationships, they -- they don't exhaust themselves. They don't ever give up. That it still -- that the -- the, I guess, dynamic, that keeps this relationship so volatile and so dangerous never goes away?

JACOBSON: Well, first of all you have to understand that -- that nobody has really studied couples over the course of an entire lifetime.

MOSS-COANE: Right.

JACOBSON: And so we don't really know what percentage of couples actually succeed in developing a normal relationship. But what we do know is that in our sample, we -- it was very rare for the violence to stop, and especially for the violence to stop along with the emotional abuse. What was more common was for the violence to go underground and be replaced by emotional abuse. And -- and this brought -- essentially put the men beyond the reach of the law, but gave them as much control and power over their wives.

And then -- or we saw the women leave. And so I think what happens is over time, either the violence gradually gets transformed into emotional abuse or it simply continues or the woman gets out. And eventually by 20 years later, by the 20 years after we've met them, most of those relationships are resolved -- are dissolved, either because someone gets killed, usually the wife, but more commonly because she gets out. And she gets out not unscathed, but she gets out.

MOSS-COANE: Well, it's interesting because as you have said, we know a lot more about domestic violence. We know a lot more about abusive relationships. And yet, the problem continues at a fairly scary level. And I'm -- I'm curious about, then, where do we go next? "We" meaning as a culture and people like you that are researching this problem.

JACOBSON: Well, I'll tell you where I'm going next. I'm -- I've put my resources and my energy into strengthening advocacy for battered women. I want to study different methods of advocacy. I'm interested in following women into their next relationships.

I'm interested in helping strengthen the technology that currently exists in advocacy programs. And at the policy level, I'm interested in lobbying for the funding of programs which give women an opportunity to rebuild their lives after they've been through this concentration camp-like experience.

MOSS-COANE: Well, I want to thank you very much, Neil Jacobson, for joining us today on FRESH AIR. Thank you.

JACOBSON: Well, thank you very much for having me.

MOSS-COANE: Dr. Neil Jacobson is the co-author of When Men Batter Women.

I'm Marty Moss-Coane and this is FRESH AIR.

Dateline: Marty Moss-Coane, Philadelphia
Guest: Neil Jacobson
High: Neil Jacobson is Professor of Clinical Psychology at the University of Washington, and a pioneer in the scientific study of marital therapy. He is co-author -- w/John Gottman, author of "Why Marriages Succeed or Fail" -- of "When Men Batter Women: New Insights into Ending Abusive Relationships." The book is based on their decade of research with 200 couples in which they observed the arguments of severely violent couples. Their research shatters a couple of myths: that women batter too, and that women often provoke men into battering them.
Spec: Family; Marriage; Spousal Abuse; Health and Medicine; When Men Batter Women
Please note, this is not the final feed of record
Copy: Content and programming copyright 1998 WHYY, Inc. All rights reserved. Transcribed by FDCH, Inc. under license from WHYY, Inc. Formatting copyright 1998 FDCH, Inc. All rights reserved. No quotes from the materials contained herein may be used in any media without attribution to WHYY, Inc. This transcript may not be reproduced in whole or in part without prior written permission.
End-Story: When Men Batter Women
Show: FRESH AIR
Date: MARCH 02, 1998
Time: 12:00
Tran: 030202np.217
Type: FEATURE
Head: Living with Our Genes
Sect: News; Domestic
Time: 12:30

MARTY MOSS-COANE, HOST: This is FRESH AIR. I'm Marty Moss-Coane, in for Terry Gross.

When a couple welcomes their new baby into the world, they usually vow to be the best parents possible by providing a nurturing, stimulating environment. They've probably bought a library of baby books about childrearing dos and don'ts, believing that everything they do makes a difference.

My guest Dean Hamer says while parents may exert some influence over their children's personalities, genes may play as significant a role. Hamer is the chief of gene structure and regulation at the National Cancer Institute's Laboratory of Biochemistry, and has been doing research on the link between styles of personality and human DNA.

His new book "Living With Our Genes" looks at a range of traits, including thrill-seeking, depression, and worry. By taking blood samples and correlating them to psychological tests, Hamer says he found a genetic link to these behaviors.

Dean Hamer got a lot of attention with his research into the so-called "gay" gene, which he wrote about in his 1994 book "The Science of Desire." There's a lot of interesting gene research that's currently being done, and there's a lot of hype about genes making people behave in specific ways.

I asked Dean Hamer if genes are destiny.

DEAN HAMER, CHIEF OF GENE STRUCTURE AND REGULATION, LABORATORY OF BIOCHEMISTRY, NATIONAL CANCER INSTITUTE, CO-AUTHOR, "LIVING WITH OUR GENES: WHY THEY MATTER MORE THAN YOU THINK": Genes are not destiny, just like the blueprint of a building doesn't tell you exactly how the building is going to turn out or how that building is going to be used. Genes are only a rough guide for the formation of the body and of the brain.

MOSS-COANE: And are your genes almost like mine?

HAMER: I can say that your genes and my genes are probably 99.9 percent similar. That's why we're both human beings. But there is a difference about one out of every 1,000 bases, and those differences are enough to make big differences, for example, in the fact that you're female and I'm male; that you're who you are and that I'm who I am.

MOSS-COANE: From the research that you have done, do you see your own heredity at work? Your own genes at work in your personality?

HAMER: You know, it's interesting. I used to always look at my own DNA. I was the first DNA -- human DNA family I ever made was from myself. But I stopped doing that a couple of years ago because I realized that when I learned about my genes, I also got information about my parents and my sisters that, as it turns out, they didn't really want to have revealed.

And so, I don't look at my own DNA anymore. But I imagine I probably have the gene for novelty-seeking because what I'm working on is pretty new. I probably don't have the gene for anxiety. I don't think somebody who is very anxious would do this type of research. But those are just guesses.

MOSS-COANE: What made you want to look at your own DNA to begin with?

HAMER: I was the easiest person to get a blood sample from.

LAUGHTER

MOSS-COANE: It was a practical solution, yes?

HAMER: Right. No one could complain that, you know, I was doing something that they didn't want done.

MOSS-COANE: But did you approach this with any degree of trepidation? Looking at your own DNA?

HAMER: You know it's interesting, five years ago I didn't really even stop to think about that. And five years ago, we didn't know any genes that were involved in behavior. That's changed recently. For example, now there is a gene very well-identified that greatly increases the risk for Alzheimer's disease. We know that gene. We can assay it. I personally wouldn't want to know if I have that gene, because of course at this point, there's nothing that you can do about Alzheimer's disease.

So it would be interesting information, but I think not useful and possibly even dangerous or damaging information for me to know.

MOSS-COANE: Well I would think another challenge for this kind of work is to figure out this nature/nurture question, which is: how do you separate out a family environment? How a parent relates to a child? Whether some big trauma happened in a person's life and what impact that might have on their genes? How do you wrestle with those questions?

HAMER: Well of course, we're interested mostly in the nature side because we're geneticists, but nurture also is very important. We know that environment is at least 50 percent of most behavioral traits. The way we separate that out is that we look, for example, at brothers and sisters that were raised up in the same family, have pretty much the same environment, and see within that context whether the genes have an effect.

If they do, then there must be something that the genes were effecting that can't be explained by the environment.

MOSS-COANE: You say that a -- that the shared environment that people have, and this would be their home environment or their school environment, or their social class, really has little impact on personality. And I would think that developmental psychologists and parents would argue with you about that.

HAMER: Well this has been a really big surprise of this research, is how little the shared environment, like school system, really matters, by the time a person develops into an adult. For example, if you look at something like body weight, which is controlled by eating habits, and you look at children that have been adopted -- they have the same body weight as their biological parents and a completely different body weight than the adoptive parents.

In fact, what happens is that when somewhat overweight parents adopt a child, the child on average will get an even lower weight, perhaps because the parents are concerned about the eating habits. So at first, this seems counter-intuitive. Actually, if you ask parents that have had two or more children, I think that they will probably realize more and more that what they do with the kid is not so important as who the kid is. And that really starts at birth.

MOSS-COANE: But you're not saying that it doesn't matter how you treat your child or whether you yell at them or speak to them in a careful voice about something that they have done that -- that's been wrong or bad.

HAMER: There's no doubt that parenting is important, and I think you were referring to let's say anti-social behavior -- being a juvenile delinquent, acting out at school. Some very interesting studies have shown that that's type of behavior really is a combination of genes and environment.

Kids who come with genes -- "bad" genes, let's call them -- genes that tend towards anti-social tendencies -- do fine, if they're adopted into a household where the parents do well and treat the kids well and are loving and supportive.

If those same children, however, get adopted into a household where the parents are not so supportive; where there are problems in the family; then they are greatly increased risks for troublesome behaviors.

MOSS-COANE: Dean Hamer is the co-author of Living With Our Genes. We'll talk more after a short break, about the link between DNA and human personality.

This is FRESH AIR.

Dean Hamer is our guest, and his book is called Living With Our Genes.

Let me talk to you a little bit about the research that you've done looking at thrill-seeking and anxiety. But again, if we're talking about teasing out a certain personality trait, it seems to me that dealing with the body, you're talking about 100,000 genes. You're talking about biology and experience -- that there is this synergistic relationship between all these variables.

HAMER: There is a tremendously complex relationship between different personality traits; between the personality traits and actual behavior between environment and the traits; between all of these different genes. And so, what's really astounding is that we can now pinpoint individual genes that at least play some role in that complex intermixture.

MOSS-COANE: Well let's talk about thrill-seeking, and this is something that you write about in your book. How would you describe thrill-seekers?

HAMER: Well, thrill-seeking is a measure of people's interest in novel stimuli, and if I wanted to ask you one question to figure out whether or not you were a novelty seeker...

MOSS-COANE: OK.

HAMER: ... I might ask you if you're in a new country where you've never been before, and it's lunchtime and you're hungry and you're walking down the street, on one side you see a McDonalds and on the other side you see a little shack selling a local delicacy -- fried goat testicles, for example.

Where would you go for lunch?

LAUGHTER

MOSS-COANE: Well, I would have to pause there because I'm not sure about the goat testicles. But I sure would be tempted to try out that new place, but...

HAMER: Well, you may then have the gene for novelty-seeking.

MOSS-COANE: Right -- I mean, it wouldn't be a beeline over there. I'd have to think about it.

HAMER: Well, you may also have a gene for anxiety, which inhibits you a little bit. And that's a good thing.

MOSS-COANE: Because you -- it could be dangerous to be thrill-seeker.

HAMER: Exactly. Thrill-seekers like exciting activities like bungee-jumping or skydiving or extreme skiing. They also may like intellectually exciting activities, like abstract art or trying out transcendental meditation. But they can also like things that aren't necessarily so good, like experimenting with new drugs, having multiple sexual partners, gambling and so on.

MOSS-COANE: OK, so we have this -- this personality-type -- this novelty-seeker, this thrill-seeker. How do you -- how did you then do the science which makes then this connection to some kind of genetic marker?

HAMER: Well, we knew that the brain chemical that's responsible for feeling good in response to new stimuli is a chemical called dopamine. And it's sort of the brain's pleasure chemical. Dopamine is what makes people feel good if they've had a delicious meal, if they've smoked a cigarette or had a hit of cocaine, or if they've had a new sexual experience.

And so we wondered whether there was some connection between this pleasure chemical dopamine and peoples' levels of novelty-seeking. To look at that, we looked at a molecule called the dopamine receptor. It's the lock into which dopamine fits as the key. And we found out people have different types of dopamine receptor genes. Some people have a form that's turned on by dopamine in response to new stimuli. Other people have a form that's not turned on.

So, some people get a thrill out of new things. Some people go bungee jumping and it makes them feel good, and that's because they have this form of the dopamine receptor. Other people can do the same experience, they don't feel so good, in part because they have a different dopamine receptor.

MOSS-COANE: Are you saying that it's not the gene that makes you seek the novelty, it's the fact that the dopamine makes you feel good if you do engage in these thrill-seeking behaviors?

HAMER: Exactly. The gene just makes a protein that controls how well dopamine makes you feel. So it's not like the gene is whispering into your ear: "jump off this cliff" or "go see the yoga." The gene is just making a protein that controls how good you feel; how rewarded you feel in response to a new stimulus.

MOSS-COANE: Well, another trait that you looked at, and perhaps it's almost the opposite of thrill-seeking has to do with -- with worry or anxiety. And you describe this as -- excuse me -- as a trait with deep biological roots. How come?

HAMER: Psychologists have shown that the roots of anxiety and worry can be traced to children even before they are born, and that by the time children are a year or so old, that there's a real division between those who are worried, anxious, fretful, cry a lot, don't like to leave mommy's side -- and those who are more peaceful, pacific. They may coo and giggle. They smile at strangers.

And that trait really lasts throughout a lifetime. Children that were fretful and worried grew up to be adults who, on average, are a little bit more neurotic, depressed, and worried. And children who were calm and happy are more likely to grow up to be extroverted, sociable sorts of adults.

MOSS-COANE: Are you saying then that worry runs in families because of genetics? Or, could it be that this is an anxious and slightly depressed family that then, you know, creates an atmosphere of worry?

HAMER: Well certainly worry, anxiety, depression does run in families. The Hemingway family with the multiple suicides and deaths is a classic example of that. It's probably a combination of upbringing and of genes, but our research suggests that genes are the most important of those factors. Even children that are adopted into new households with new parents who may be very cheerful, still show the depressive or neurotic qualities of their biological parents.

MOSS-COANE: What, then, is the chemical or genetic, then, link? Where did you go to look to try to find that link associated with worry?

HAMER: Well, the key chemical for worry is called seratonin. It's sort of dopamine's evil twin.

LAUGHTER

Seratonin is what makes you feel bad; what makes you feel anxious and depressed. And the big clue in this research was from a very popular drug called Prozac. Prozac of course is an anti-depressant. It's also used to treat people that feel anxiety; that feel hostility; that feel pessimism. And, Prozac acts directly on seratonin. It changes the levels of pre-seratonin by interacting with a protein called the seratonin transporter.

So we wondered whether or not people would have a difference in the gene for the seratonin transporter. Would there be a sort of natural genetic Prozac that people are born with? And we looked at that gene real carefully and we found out that there is a difference. Some people have a form of the gene that's like a natural Prozac. It's as if from conception, they've been taking Prozac.

Other people have a form of the gene that doesn't work so well, and it's like they're not on Prozac.

MOSS-COANE: Well let me ask you a sixth grade science question: what literally does that look like?

HAMER: What that looks like is that at one point in this gene, your sequence might read A-G-G-A-G-G but mine reads A-G-G-A-G-G-A-G-G. It's sort of like a musical tune that's repeated over and over, but sometimes some people forget a stanza. They only repeat it three times instead of four times, or four instead of five.

MOSS-COANE: And you can definitely say that that variability is tied, then, into these specific behaviors that we've been talking about.

HAMER: Well, we looked at people with the different forms of the gene, and we found that people with the Prozac form of the gene, if you will, had lower levels of anxiety, lower levels of depression, lower levels of pessimism. They were also less aggressive, less hostile. They looked like people that were on Prozac. It wasn't an absolute effect. There are people who are depressed who have the good form of the gene. There are people who are -- have the bad form of the gene who are perfectly happy. But, there's a strong correlation.

MOSS-COANE: We're talking with Dean Hamer and his book is called Living With Our Genes. He's chief of gene structure and regulation at the National Cancer Institute's Laboratory of Biochemistry.

Well, let's talk about sex and reproduction.

HAMER: All right, let's talk about sex.

MOSS-COANE: Which of course you describe as, you know, one of the most powerful human drives. And of course, it has to do with our survival.

When you look at men and women and sex and reproduction, what kinds of differences do you find?

HAMER: Well, as I say, men are from Venus and women are from Mars, or perhaps it's the other way around. And some people think that's all because of the way we portray men and women in TVs and radio and magazines and so on. But there's actually a strong evolutionary difference for many of the differences between men and women.

And that is that men's genes do best by acting as if the men were sperm. There are a lot of them. They're abundant. They only have a few chances to reproduce. And so, they want to have sex with as many partners as possible, as frequently as possible.

And women will tend to act in behalf of their eggs, which are rare, which are valuable. They have to really think about things or consider things before they make a reproductive decision. And so, there is more likely to be a desire for partners that can provide resources, that will stick around for the care of the child.

And that translates into some of the behaviors that are very different between men and women.

MOSS-COANE: So we're back to the stereotypes of men and women -- she wants a guy with a big wallet and he wants a woman with big breasts.

HAMER: You said it.

LAUGHTER

MOSS-COANE: This is as far as we've come in terms of evolution, right?

HAMER: Well, one of the differences -- yeah -- one of the differences that people have always said "oh, that's biological" or "that's genetic" -- or they've said "oh, that's completely cultural -- that's because of stereotypes." We're now able to trace a few genes that are directly involved in those different sexual behaviors.

MOSS-COANE: Now, as you describe men and you said men behave like sperm, which is that they are interested in many partners and interested in a lot of sex. I mean, it sounds like men, then, are novelty-seekers.

HAMER: Well, men are novelty-seekers, and some more so than other. One of the fascinating connections we found between genes and sex is in the gene for the dopamine receptor. Some people have a form that make them eager to experience novel stimuli. Other people have a form of the gene that makes them less interested in new stimuli.

And that translates into interest in new sexual partners. Men who are high novelty seekers are more likely to seek out a variety of partners, and also unusual partners. For example, heterosexual men may sleep with another guy just for a new experience. Or, gay men may sleep with a woman just for a new experience.

MOSS-COANE: You say looking at female sexuality and even sexual orientation, that that is less genetic- or biologically-based and more culturally and environmentally influenced. Explain what you -- what you're saying there.

HAMER: Well, I think people have realized for a long time that woman's sexuality is a bit more flexible, less hard-wired than it is for men. Women are more likely to change their orientation over time. They're more likely to have mixed interest. And now, genetic and twin experiments have shown that that's in part because genes are less important for determining a woman's sexuality and sexual orientation than the genes are for men.

MOSS-COANE: Well, how do we know that?

HAMER: The way that we know that is that if you look at identical twins, and one of them is a gay male, his identical twin will have about a 50 percent chance of also being gay -- much higher than in the general population and much higher than in fraternal twins. And that means that genes are important of male sexual orientation.

When that same experiment was done with women, a very different answer emerged. Both the identical and fraternal twins had the same chance of identifying as lesbian. And if the two twins were raised up separately in different households, then there wasn't any relationship at all.

So, that says that genes are less important for female sexual orientation and that something else -- perhaps something in the environment, perhaps something in the culture, is playing more of a role in women.

MOSS-COANE: Do you think there's an evolutionary explanation for that?

HAMER: The classic evolutionary explanation is that you only need one sex of the two to be interested in sex. And in the human species and in other mammals and higher species, that appears to be males.

MOSS-COANE: Dean Hamer is the chief of gene structure and regulation at the National Cancer Institute's laboratory of biochemistry, and co-author of Living With Our Genes. We'll talk more after a short break.

This is FRESH AIR.

Well again, our guest on FRESH AIR today is Dean Hamer. We're talking about genes. It's the topic of his book. It's called Living With Our Genes.

Let me go back a couple of years to the discovery of the so-called "gay gene." And this was based on some research that you did looking at brothers and finding some kind of correlation between genetic markers and homosexuality.

You got criticized for that, and I guess criticized that the -- the research that you did was too narrow. Do you think that was a fair criticism?

HAMER: I think any research on human sexuality is going to be criticized, no matter what the results are, because it's such a controversial and such a personal topic as well.

The results on male sexual orientation have held up, and we haven't discovered the gene yet, but my own laboratory and others are looking very hard for it. And once we have that information, we'll have some, you know, real knowledge about the connection between genes and sexuality.

MOSS-COANE: Why are you interested in this particular topic?

HAMER: Well, there's a good biological reason, which is that sex is the driving force for all of evolution. Understanding the basic mechanisms -- the genetic mechanisms, the brain mechanisms -- that cause sexuality is very important.

We actually started that research for another reason, which was to look at HIV and AIDS and a particular outcome of AIDS called Kaposi's Sarcoma. I think that it's practically important that we do more research on human sexuality -- try to understand why people behave the way they do, especially in the era of AIDS, where sexual behavior has become such an important health factor.

MOSS-COANE: So, you were looking at brothers?

HAMER: We looked at families where there were two gay brothers, and we asked the question: is there any genetic peculiarity or similarity between them? Found a gene region on the X chromosome, which is one of the sex chromosomes, that correlated for sexual orientation. It's not an on-off switch for homosexuality, but it does play some role.

MOSS-COANE: So you found a -- a region and not a gay gene, because of course the headlines were a gay gene.

HAMER: Well, you people in the media simplify things sometime. It's not actually a gene at this point. It is a region -- a big chunk of the chromosome -- a region that could contain about 500 different genes. And now, the search is on to narrow that down to find the needle in the haystack.

MOSS-COANE: Although I think the subtitle of your book about it had something about the gay gene -- to defend the press.

HAMER: In quotes, yes.

MOSS-COANE: In quotes -- in quotes.

LAUGHTER

Looking at a connection between genes and homosexuality, what does that say about everyone else's sexuality? Looking at heterosexuality?

HAMER: Oh sure. Sometimes people think that there is a gay gene and that if you have that gene, you're gay and that people that don't have that gene at all are heterosexual. But actually, that's really not right. There is probably a sexual orientation gene, or many sexual orientation genes, and it can come in different varieties. It can come in a gay variety. But most of the time, it comes in a straight variety.

And we were actually able to show by looking at gays and their heterosexual brothers that the same gene region is involved in heterosexuality. So, this isn't really a gay gene. It's an orientation gene that comes in different varieties.

MOSS-COANE: If we're talking about a -- a gene that defines sexual orientation -- we'll say homosexuality -- are you concerned that if that's found that then there will be some kind of a screening test to screen out these potential children in utero?

HAMER: I think that that would be unethical. I think it would be wrong. I think it should be legislated against. Fortunately, it's not going to actually happen, because we already know that this gene only has a modest influence on sexual orientation; that just by looking at a blood sample or a DNA sample, one could not definitively predict the sexual orientation of a child.

So not only would it be unethical, it would be scientifically unsound as well.

MOSS-COANE: I wonder, too, as people begin to think more about genes -- their own genes I guess and everybody else's's -- whether we'll begin to medicalize human variability; that we'll look at what perhaps makes someone interesting and idiosyncratic -- we'll begin to look at it in kind of -- in a medical way; in a way that "they've got a problem" as opposed to "gosh, they're interesting."

HAMER: I think what will happen is that for a relatively short period of time, there will be some medicalization and that normal variations in behavior will be seen as some sort of extensions of pathology. But what will happen within a decade or so is that we'll quickly realize that everybody has a whole bunch of "bad" or "good" genes; that we are all a little bit crazy; that we are all a little bit sick; that we all have the potential for this disease or that disease; that we'll all die eventually.

And that as that is recognized, there will be less stigmatization and we'll return to a sort of a more normal view.

MOSS-COANE: Do you think, though, that this will create drugs to deal with anxiety -- I mean, even beyond Prozac. I guess to some degree we're already doing that -- but drugs to deal with thrill-seeking or cigarette-smoking and other issues?

HAMER: Well I think the first development will actually be in diagnosis, rather than in new drugs. For example now, when somebody goes to a psychiatrist and says "I feel really lousy; I can't get out of bed; I don't want to eat." The psychiatrist says: "aha, your diagnosis is depression" -- which isn't really a diagnosis at all. It's just saying that you're showing all the signs of depression that other people show.

Some point in the future, the doctor will be able to listen to all of that, which will be important, but also look at the person's DNA and say: "ah, you have the sort of depression that's because you have bad seratonin transmission." Or the doctor may look and say: "you have depression, but you don't have any problem with your seratonin. Let's talk about your life a little bit more and about what's going on with you."

So I think that will be the first, and a very important, development.

MOSS-COANE: Well Dean Hamer, thank you very much for joining us -- a very interesting discussion. Thank you.

HAMER: Hey, thanks Marty.

MOSS-COANE: Dean Hamer is the co-author of Living With Our Genes.

Dateline: Marty Moss-Coane, Philadelphia
Guest: Dean Hamer
High: Dean Hamer is Chief of Gene Structure and Regulation at the National Cancer Institute's Laboratory of Biochemistry. He's the co-author of "Living with Our Genes: Why They Matter More Than You Think." The book is about Hamer's research looking at how specific genes are linked to our behavior: traits like anxiety, thrill-seeking, and homosexuality.
Spec: Health and Medicine; Psychology; Genetics; Technology
Please note, this is not the final feed of record
Copy: Content and programming copyright 1998 WHYY, Inc. All rights reserved. Transcribed by FDCH, Inc. under license from WHYY, Inc. Formatting copyright 1998 FDCH, Inc. All rights reserved. No quotes from the materials contained herein may be used in any media without attribution to WHYY, Inc. This transcript may not be reproduced in whole or in part without prior written permission.
End-Story: Living with Our Genes
Transcripts are created on a rush deadline, and accuracy and availability may vary. This text may not be in its final form and may be updated or revised in the future. Please be aware that the authoritative record of Fresh Air interviews and reviews are the audio recordings of each segment.

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