Are men better at solving problems involving physical spaces, shapes and forms? Researchers at UC San Diego find it may be more nurture -- than nature.
October 5, 2011 1:11 p.m.
Dr. Moshe Hoffman, post-doctoral student, UC San Diego, Rady School of Management.
Related Story: Are Men Better Than Women At Spatial Abilities?
CAVANAUGH: This is KPBS Midday Edition. I'm Maureen Cavanaugh this month, we celebrate 100years of California women having the vote. And we're doing a series of reports on Midday Edition this week in keeping with the theme of women's empowerment. And today's topic comes from a somewhat unlikely source. 2 small villages in India. A recent sociological experiment conducted by researchers from UC San Diego is casting down on 1 of the most widely accepted gender differences. That is men's inherent superiority in spatial ability. Joining me to discuss this finding is my guest, doctor Mosha Hoffman, postdoctoral student at Reidy school of management. Welcome.
CAVANAUGH: Can you tell us what exactly spatial ability is?
HOFFMAN: Sure. Spatial ability corresponds to 1's ability to kind of close your eyes and imagine in your head something spatial, like if you close your eyes and you want to think about where the light switch is, related to the door. Or where you would have to move your arm in order to reach that light switch. Traditionally, this is measured using the mental orientation task. Where you see, say, 2 tetric pieces, 1 on a computer screen on the left and 1 on a computer screen on the right, and you're asked are these the same, 1 is a rotation of the other, or are they 2 completely different pieces? People who are good at this task are thought to be better at imagining things in their mind's eye.
CAVANAUGH: I see. So if you would, can you remind us what's been the accepted wisdom about the gap between men's and women's spatial abilities?
HOFFMAN: Sure. So there have been hundreds of studies done in the west, and in many other countries where we found that men tend to be much better at spatial abilities than women. And this is kind of the most robust gender difference in cognition that has been found. And it shows up in study after study after study. Not in artifact of every single researcher. This is hundreds of studies, and shows up every single time. So it's a very, very strong effect.
CAVANAUGH: And why do spatial abilities matter?
HOFFMAN: Well, people who are better at spatial abilities are more likely to, say, major in the math and sciences, and engineering classes. They're more likely to perform better in these places. They're more likely to end up going into careers in these fields. In fact, 19% of people in what's known as the stem field, science, technology, engineering and math Micks are women. And it's thought that part of the reason why is because women are less good at spatial abilities, and spatial ability correspond to how likely you are to choose these professions and how you're going to be at them.
CAVANAUGH: What is that break down again? Men to women in the technical and spatial ability?
HOFFMAN: It's about 19%
CAVANAUGH: 19% of women as opposed to 81% of men
CAVANAUGH: Okay. Now, your research involved 2 tribes in India. I think the story of how you actually decided to take on this particular research is very interesting. What happened?
HOFFMAN: Well, you want to hear more about the literature that was going on before?
CAVANAUGH: Well, you were going into India.
HOFFMAN: Oh, absolutely. So we were on our way to India. I was on route stopping off in Jerusalem for a conference. And my advisor, Ori Ginizzi, who is also at Reidy school of management was taking vacation in Tel Aviv. And called me said, and said you want to spend the afternoon together? We met on the beach, and he was smoking a cigar, and I was drinking a coffee, and he was asking me what we had planned. And he said, No, let's come up with something better. We have these 2 great societies here. The Khasi, this matrilineal society, and the Karbi, the patrilineal society which are almost identical and he want for culture. They have the same ethnic group, the same means of subsistence, and the same geography and climate. What could we do to exploit this, what scientists call a natural experiment, where people are kind of naturally put into this experiment where they're assigned to 1 society or another. And they're so similar, except on this 1 variable we might care about: Gender equality. So we were thinking how can we use that to our advantage?
CAVANAUGH: Let me slow you down for a second. Because I think you said the name of the 2 villages and the 2 tribal people. And I don't know that people got there. You had 2 of them, 1 of them was the Karbi. Tell us about the Karbi village and tribe.
HOFFMAN: They are a matrilineal society which is to say that the men are not allowed to own property, and the youngest daughter actually inherits everything. And the women there are treated considerably better than in the neighboring patrilineal society, the Karbi. And in the Khasi, the women get the same education as men on average, whereas in the Karbi, they get on average 2years less. In the Karbi, it's the oldest son who inherits the property. And if you ask people whether they want to have a son or daughter, in the Khasi, they'll tell you we don't really care. We love them both. Except if you push them, and say, you can only have 1, they'll say then of course we want a daughter because we need to pass on the family name, and we need to pas on the property to someone. And that's very unusual for India or any developing country to actually have no preference or prefer daughters to sons. Whereas in the Karbi, this is a fairly typical society where women are often mistreated. It wasn't uncommon for a woman to have very little education to get married very young for a man to beat his wife, and the women have much less power. And for instance, when I asked 1 woman who is 20years old, when was the last time she went to school, she said, well, I've been married for a little bit now. The last time I went to school I was in the equivalent of sixth grade. And I asked her why, and she says, well, because I'm a woman. You know I'm not smart enough to understand what they teach me in school and it would be I complete waste anyways because how am I going to use that in my married life?
CAVANAUGH: So we have the -- what could very easily be described as the male dominated Karbi tribe as opposed to the Khasi tribe, which is a little bit more egalitarian, and also the inheritance goes through the female line.
CAVANAUGH: So you already knew that there were these 2 different villages, these 2 different tribe, already in India. And they -- they're differentiating, the way they went about doling out power and education was already pretty well known.
HOFFMAN: Yeah, absolutely. It's been studied by anthropologists before. So they're kind of thought to be 1 of the 2 extant most traditional matrilineal societies around, the other being the Na in China. And others have studied them in the past, including the 2 coauthors on this paper.
CAVANAUGH: So what did you decide -- what kind of an experiment did you decide to do?
HOFFMAN: We decided we would measure spatial abilities given all this literature showing that there's a huge gender difference. And it's so robust. And there's been a lot of literature trying to understand why is this spatial ability different, why are women so much worse at spatial abilities? What is the role of nurture? So we thought it would be the perfect place to look. Because we have this great control for biology, we kind of -- these 2 societies are so similar, biologically, they come from the same ethnic group. And the only thing that varies is culture. That allows us to identify the effect of culture. It's the perfect tool to address that question. And if we find big differences in the gender gap in spatial abilities in 1 and smaller in the other, that says culture can play a big role. And that's a very important question to ask, is what is the role?
CAVANAUGH: What did you actually go about measuring spatial ability aptitude in these 2 tribes between men and women?
HOFFMAN: Unfortunately we couldn't use the traditional measure that I described before with these tetric pieces because it was too abstract. These villagers don't have the same experience that we have with abstract reasoning. So for instance, I was looking through their school textbook, which many of them don't even go to school. They just work the fields: But the ones who do learn things like what is the capital of India, what did India earn its independence? Not questions like why is it important that India earned its independent. What does it mean to be an independent country? So much less abstract than the type of education that we have. So to think about a rotating object and whether this object is the same is something that we as westerner, questions that we're used to. But that would be too hard for them. And hard for them to even -- understand what we're asking. So we came up with this puzzle. The same thing that a kid in the U.S. would do growing up, many, many times. These people have never experienced this before. So they had never used a puddel before. And we just had a floor piece, cubic puzzle that kind of when put together properly formed the face of a horse.
HOFFMAN: And some people were better at this than others.
CAVANAUGH: And we have a picture of that on our website at KPBS.org, the actual puzzle that you used with the Karbi, and the Khasi describes. So you present a group of people. What ages you were looking for?
HOFFMAN: Adults, so 18 plus. We had everybody from 18 to in their '70s. And in our statistics, of course, we look at age effect, and we controlled for age.
CAVANAUGH: Okay. So they lined up, and they took these puzzles. What did you find in the Karbi tribe?
HOFFMAN: So, there we find that there are large differences between men and women. Women take about 1 and a half times as long to solve this puzzle, 45seconds compared to, say, 30seconds. Whereas in the matrilineal society, the Khasi, there were no gender gaps at all. So men were no quicker than women at solving this puzzle
CAVANAUGH: Were you surprise bide that first off?
HOFFMAN: Oh, very much. So it isn't at all obvious, even if we think that things in our society can affect women's performance at these kinds of tasks. It's not obvious that the effect could last so long and could spread throughout the entire society and be so strong. And we thought maybe there'd be a small effect or some effect or maybe not even 1 at all. But to completely eradicate the gender difference, that was shocking.
CAVANAUGH: Because, especially evolutionary biologists have come up with, you know, very, very detailed reasons why men's spatial abilities are better than women's. They have to hunt, they have to shoot arrows, they have to build homes, you know, going back into the age was human society. And yet from your -- what seems to be the linchpin in whether or not someone knows how to navigate and can imagine spatial relations
HOFFMAN: Yes. So our study allows us to conclude that socialization, culture does play a big role in the gender difference in spatial abilities. But I do want to caution the listener that these 2 societies are identical in biology and different on culture. So we look at the effect of nurture. We can't really conclude that nature does or does not play pay role because we're holding that fixed. So it could very well still be that there are innate differences. We can't really say anything about that in the study. What we can say is holding in those differences, if you change culture, that can play a role
CAVANAUGH: You're very quick to point out in your research too that this is just 1 study.
CAVANAUGH: How is it being received?
HOFFMAN: Well, it's been getting a lot of attention from the public and from other researchers. People are very interested, and they -- the 1 thing that seems to grab people is this nice contrast develop these 2 societies. So there's a lot of cross cultural research done with many different societies. But in those studies, you don't really know what's driving the effect. Because different societies differ not just on culture but on, say, what genes people have or what the climate is. And you don't really know then -- you can't really isolate the effect of culture and be certain it's culture that's driving it. So that was the unique thing about the study that made it grab so much attention. Now, we have been getting a little bit of criticism because unofficial we couldn't use the standard measure. And in science, it's always great if you can use the same measure everybody has been using in the past. And unfortunately we do not have that ability here. So it's hard to compare our results to previous results because we're not using this standard mental orientation task
CAVANAUGH: And have you thought about what it is about the way that girls are raised and the kind of power that's given to them that could actually change an ability to grasp spatial dimensions and relations?
HOFFMAN: Yeah: So there is some literature before us suggest the various means by which socialization can matter. For instance, if you take an engineering course, you'll become better at this stuff. So far training does matter. Perhaps even playing sports, certain sports that more boys are more likely to play, like baseball, could improve your spatial reasoning. And perhaps even facing negative stereotypes, women knowing or thinking that they're worse at spatial abilities could actually hinder their performance. So there's -- there's a lot of evidence that predates us, which suggests these possible mechanisms could be out there. Unfortunately in our studies we don't have any data on stereotypes or on experience or training. The 1 thing that we do have is education levels. And we do know that in the Karbi, the women are much worse educated than the men, whereas in the Khasi, there's no difference, and in fact within each society, Karbi men who are better educated than other men are better at spatial reasoning, and the same for Karbi women and Khasi men and women. So education seems to matter across the board. Since the women in the Karbi are les'd indicated, thack be possibly what's driving our results. And we've done some analysis to suggest that about a third of our analysis is responsible for this difference.
CAVANAUGH: Wondering how long the Karbi, and the Khasi will remain so untouched and homogeneous that they are going to be able to be used as research subjects. Any speculation on that?
HOFFMAN: Not long, not long. So anthropologists have talked about a handful, perhaps, a dozen matrilineal society was recent. But these -- the Na and the Khasi are the only 2 that are still traditional. So we're losing them very quickly.
CAVANAUGH: Well, I'm glad you didn't lose them before you did your research. And I want to thank you so much for speaking with us about it. I've been speaking with doctor Mosha Hoffman, a postdoctoral student at UC San Diego Reidy school of management. Thank you.
HOFFMAN: Thank you.