'X' MARKS THE SPOT
JUNE 13, 1997
Scientific studies may make women's intuition less of a myth, suggesting now that women inherit the ability to decipher social situations from their fathers.
JIM LEHRER: Now, a pre-Father's Day look at what dad may pass on to his daughter. New scientific research was reported this week in the British journal Nature. We begin with this report from Andrew Vietch of Independent Television News.
ANDREW VEITCH, ITN: The scientists have found that a gene or a group of genes, probably acting directly on the brain, accounts for basic differences of behavior in men and women.
DAVID SKUSE, Institute of Child Health: What me might call feminine intuition, as it were, the ability to sauce out a social situation by observing non-verbal behavior by observing nuances of expression in voice and song, that that set of skills has a genetic orign.
ANDREW VEITCH: The discovery comes from studying, who like Kylie Smyth, have Turner's Syndrome, a genetic disorder which only affects women. It causes problems in social relationships, but it does not affect intelligence.
KYLIE SMYTH: It's really just a problem. It's not my whole life. It doesn't really matter that. Don't have to--
ANDREW VEITCH: The cause of Turner Syndrome is a missing X chromosome. Girls have two female X chromosomes--one from their father and one from their mother. In Turner Syndrome, one or the other is missing. Today's discovery shows that the girls who retained a single X chromosome from their father were far better socially adjusted. The conclusion is that the genes of sociability is on the X chromosome from the father.
DAVID SKUSE: Female are, as it were, genetically programmed to pick up socially appropriate behaviors in much the same way that we're programmed genetically to pick up language. I mean, nobody teaches us language. We learn how to speak our native tongue by observing other people, and so I'm suggesting that girls learn the social mores of their social group by observing other people. The boys don't have that advantage. They have to learn social skills.
ROWENA JAMES, Wessex Genetics Laboratory: It isn't disastrous for you guys. You know, you can be taught those skills which come socially to us.
ANDREW VEITCH: A boy gets an X chromosome from his mother and the male Y chromosome from his father. So he misses out on the sociability gene. In effect, he lacks female intuition. The finding may explain why far more boys than girls suffer from autism. Children find it so difficult to socialize that they appear to withdraw from the world and why men are more likely to suffer speech disorders, language difficulties, and reading problems.
STEVE JONES, University College: I think the pendulum is swinging now back to the idea that quite a few behavioral differences are influenced by genes. Twenty years ago it was almost a shocking thing to say. I think most people would accept that that's now possible. But we've got to remember that because something is influenced by genes that doesn't mean to say the environment is not important. They're not separate. They always act together.
ANDREW VEITCH: The lack of a sociability gene means boys have to be taught how to behave. They're, therefore, more open to influence by a dominant personality. That, say the scientists, makes them better material for teens, or, indeed, armies. Perhaps that's why the gene evolved this way. Unsociable men make better soldiers.
ROWENA JAMES: I think that what we found is some reason behind the fact that there are differences, but, no, I think that we as females have learned differently since time began, and we wouldn't swap you really from the way you are.
JIM LEHRER: Charlayne Hunter-Gault takes the story from there.
CHARLAYNE HUNTER-GAULT: To tell us more about genetics, environment, and human behavior we're joined by two specialists in this field. Dr. Fred Gilbert is the co-director of the division of human genetics at Cornell Medical College at New York Hospital. He's also a clinical geneticist. And Kathy Katz is a pediatric psychologist at Georgetown University Medical Center. She works with children with developmental disabilities. And starting with you, Dr. Gilbert, what do you see as the significance of this genetics study?
DR. FRED GILBERT, Cornell Medical College/N.Y. Hospital: (New York) Well, it reinforces the argument that genes contribute to behavior, and it does provide a little impetus for the argument that genes may affect the gender differences that we see in boys and girls.
CHARLAYNE HUNTER-GAULT: So how does it exactly affect our understanding about human behavior?
DR. FRED GILBERT: Well, it doesn't define or it doesn't affect our understanding in that we haven't identified the gene, and we don't know what its function is. It's an observation, and like all observations, it's subject to--to proof, to repetition, and expansion. There's a study based on a relatively small sample--80 some odd cases--and also the substrait are children with Turner Syndrome, so that they're not "normal." They're individuals who already start out with a biological problem, the fact that they have only one X chromosome, and they have hormonal differences from other girls at the same ages. So it's more complicated than just saying that this defines a behavioral change. Behavior is probably certainly affected by multiple genes. And this is the effect of only one gene.
CHARLAYNE HUNTER-GAULT: Dr. Katz, what do you think? What is your perspective on what this all says about human behavior and how genes--what influences gene--behavior?
KATHY KATZ, Georgetown University Medical Center: Well, I think that we're at the beginning of a very exciting era in terms of gene research because by studying differences in certain populations who have particular genetic problems, we develop a better understanding of what genes may contribute to certain kinds of behavior, and this kind of research with this group of girls who have a particular kind of learning profile has enabled us to begin to understand what the contribution of certain genes might be and also that there will be differences in terms of the information that's given from genes that the father transfers on to the children versus information that the mother's genes may transfer.
CHARLAYNE HUNTER-GAULT: So given Dr. Gilbert's caveat, I mean, do you accept the--at least the beginning notion that genes, you know, do influence social behavior?
KATHY KATZ: I think that genes probably strongly influence certain kinds of learning behaviors. Whether it's specifically social I'm not sure yet. I don't know that we can make that jump from the findings of this study because the girls that they looked at have a very particular learning problem, and it's not specifically social.
CHARLAYNE HUNTER-GAULT: Right. But that's the point that Dr. Gilbert just made.
KATHY KATZ: Yes.
CHARLAYNE HUNTER-GAULT: Dr. Gilbert, there's always been this debate about nature versus nurturing, that is, whether the environment contributes more to behavior, or, you know, genes. Where does this finding, however narrow it is in terms of the study, where does it place that debate now?
DR. FRED GILBERT: It doesn't change it. The debate will still go on. And environment obviously affects the way these genes --the word is the modulation of behaviors. Genes contribute to that. Environment affects that. They interact in a way that we don't understand at this point in time, and there are many genes that contribute to this, not just the gene on the X-chromosome.
CHARLAYNE HUNTER-GAULT: But in the taped piece one of the people said that, you know, here is the beginning of a pendulum swing back to the notion that behavior does--is influenced by genes. Do you see a pendulum swinging back?
DR. FRED GILBERT: Well, the pendulum ever moves--I mean, the question is whether you believe--whether you're really arguing about genetic determinism, whether you're thinking that genes absolutely determine or define your exist and limit you, as opposed to genes contributing to a total picture. They're only one aspect. Environment and the society in which you're brought up in, the number of siblings you have, they all affect the way you actually evolve. So genes are a part of this, but they're not the final and absolute determinant.
CHARLAYNE HUNTER-GAULT: What possibilities then, Dr. Katz, do you think that a study like this offers? What does it open up for scientific inquiry?
KATHY KATZ: Well, it's beginning to help us better understand what areas of particular chromosomes may contribute to what kinds of behavioral differences, and by being able to tell nowadays--which we couldn't do just a few years ago--whether the information has come from the mother versus the father, that this gives us some better ideas of which kinds of traits may be linked to specific kinds of sex chromosomes.
CHARLAYNE HUNTER-GAULT: And so what practical application do you see this having, Dr. Gilbert?
DR. FRED GILBERT: Practical I don't know, but I do agree with Dr. Katz. What this leads you to is the ultimate isolation of the gene, itself. And once you have the gene in hand it is hoped that one will be able to determine what its function is. I mean, ultimately what these genes probably do is alter the wiring diagram in the brain in some way that we don't completely understand now.
CHARLAYNE HUNTER-GAULT: Alter what?
DR. FRED GILBERT: Alter the wiring diagram in the brain. And that that is affected by the environment or modulated by the environment to produce the final behaviors that we see. Now, what we want to try to understand are what these genes are, how many there are, and how they do interact with each other.
CHARLAYNE HUNTER-GAULT: So that as we approach Father's Day this coming Sunday, what message does this send to fathers or about fathers?
DR. FRED GILBERT: That they're very important. Obviously, they contribute half of their genes to their children and that their genes are as valuable, including their X chromosome, as their Y and the other chromosomes that they contribute.
CHARLAYNE HUNTER-GAULT: What do you think, Dr. Katz?
KATHY KATZ: Well, I think fathers should appreciate that they are making a major genetic contribution, but I think it's probably equally as important that they make an important social contribution of their own to their children; that they are involved with them personally.
CHARLAYNE HUNTER-GAULT: Briefly, Dr. Gilbert, does this mean that men, boys, are doomed to be less social, or can things change if this proves to be the case, if the research proves what you think?
DR. FRED GILBERT: No, because behavior, again, is determined by societal constraints, and learned behaviors, and the environment in which you grow up, so that's not going to change. Now, whether you feel you have to impinge more on a boy because--or limit him more because he may have this genetic difference, I don't really know.
CHARLAYNE HUNTER-GAULT: All right. Well, Dr. Gilbert and Dr. Katz, thank you.