Cognitive Daily

Blogging on Peer-Reviewed ResearchWhen Lawrence Summers suggested that the reason there aren’t more women in the top academic positions in math and science is that they don’t have the aptitude for it, a firestorm was created that may have cost him his job as president of Harvard University. Sometimes lost in the hullabaloo surrounding the incident is the science surrounding that bit of speculation.

The entire August 2007 issue of Psychological Science in the Public Interest was devoted to the “science of sex differences in science and mathematics,” and Cognitive Daily will spend the remainder of this week discussing that article. The article was written by a formidable team of psychologists, led by former APA president Diane F. Halpern.

The authors begin by defining terms, demonstrating that even the terminology underlying this complex issue can be controversial and nuanced. Consider the terms “sex” and “gender.” Traditionally “sex” has referred to the biological differences between people, while “gender” covered social and environmental differences. But recent research has demonstrated that it is exceedingly difficult to separate environmental from biological differences. Brain development, for example, is influenced by hormones, which are in turn influenced by both social and biological factors. So is the structure of the brain a biological or environmental factor? Arguably, it’s both. The authors settle on the term “sex” for their article, but point out that both terms are favored by different groups.

Similarly, “abilities” and “achievement” are difficult to separate. We can’t rightly say that different people don’t have differing abilities, for two people could achieve the same (low) result on a math test — one after years of study and instruction, and one with no instruction at all. Surely the second person has more ability in this subject than the first. But ability can only get you so far. Every normal human is born with the ability to learn language. But if a child is raised without exposure to language, she won’t learn it.

Halpern et al. make a fascinating observation about IQ and intelligence: Modern IQ tests throw out questions that favor one sex over the other. Therefore the most commonly used IQ tests show no difference in results between the sexes. IQ tests, therefore, can’t tell us anything about sex differences.

Sex differences in abilities and achievement
So what can we know about sex differences? Take a look at this graph showing scoring differences on a literacy test given to fourth-graders in 33 different countries:

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Girls scored significantly higher in every country in the study. A subsequent study of 15-year-olds in 25 countries showed a similar pattern: Reading literacy was significantly higher for girls in every country studied.

In the U.S., girls get higher grades than boys in every subject (including math and science), and females have a significantly higher college graduation rate than males.

So if boys are supposedly better, where are differences coming from? Well, boys do score better on the SAT test — both verbal and mathematical. In the verbal portion of the test, the male advantage is eliminated if the analogy portion of the test is eliminated; arguably this is more a test of mapping relationships than literacy. As for the math portion, one study suggests that if questions requiring mental rotation are removed, again the male advantage is removed.

Mental rotation tasks (see this CogDaily post), which require working with a three-dimensional representation of an object, have been found to have very large sex differences favoring males. The authors argue that the male math advantage in a number of different studies appears to be directly related to visuospatial skills, the most important being mental rotation. In tests on calculation or other mathematical problems that don’t require visuospatial skills, females perform just as well as — or better than — males.

What’s more, at least one study has found that it’s possible to teach these visuospatial skills. Such a course has been offered at Michigan Tech for many years, and students taking the course have not only shown measurable improvement on visuospatial tests, they have gotten better grades in subsequent engineering and graphics courses.

So while there is some reason to believe that females might not be as good at math and science as males on average, there’s also evidence that education can reduce or remove this gap. Further, the authors point out that success in math and science doesn’t depend solely on math skills. Strong reading and writing skills are essential in these fields as well, and here females have a clear advantage.

But there are other possible reasons that women are underrepresented in math and science. We’ll explore some of them tomorrow.

Why aren’t there more women in science and math? Part 2
Why aren’t there more women in science and math? Part 3

Halpern, D.F., Benbow, C.P., Geary, D.C., Gur, R.C., Hyde, J.S., & Gernsbacher, M.A. (2007). The science of sex differences in science and mathematics. Psychological Science in the Public Interest, 8(1), 1-51.

Comments

  1. #1 Jorge Gajardo Rojas
    September 25, 2007

    I more concern about gender differences in genious in philosohpy and painters in the world history.Men exceed at large to women

  2. #2 Todd
    September 25, 2007

    I realize I’m being lazy here, but do you have a reference to the study that trained mental rotation? I’m fairly familiar with this literature, but have never run across it.

    Thanks!

  3. #3 Peggy
    September 25, 2007

    Todd,

    Here are some references for you:

    “A Course in Spatial Visualization and its Impact on the Retention of Women Engineering Students,” S. A. Sorby, Journal of Women and Minorities in Science and Engineering, Vol. 7, No. 2, 2001, pp. 153-172.

    “Cross-Cultural Comparisons of Gender Differences in the Spatial Skills of Engineering Students,” S. Sorby, C. Leopold, & R. Gorska, Journal of Women and Minorities in Science and Engineering, Vol. 5, No.3, 1999, pp. 279- 291.

    “Developing 3-D Spatial Visualization Skills,” S. A. Sorby, Engineering Design Graphics Journal, Vol. 63, No. 2, Spring 1999, pp. 21-32. (Received Editor’s Award for best paper of Volume 63 of the Journal)

    “The Development and Assessment of a Course for Enhancing the 3-D Spatial Visualization Skills of First Year Engineering Students,” S. A. Sorby and B. J. Baartmans, Journal of Engineering Education, 89(3), July 2000, 301-307.

    “Making Connections: Spatial Skills and Engineering Drawings,” B. J. Gimmestad and S. A. Sorby, The Mathematics Teacher, Vol. 89, No. 4, April 1996, pp.348-357.

    From Sheryl Sorby’s web site, http://www.cee.mtu.edu/people/sas.html.

  4. #4 RPM
    September 25, 2007

    Rather than means, what if you compare the distributions of scores between males and females? Or do you plan on doing that in a future post?

  5. #5 Denise
    September 25, 2007

    #1 If you’re concerned about how men exceed women when it comes to being represented in art/world history, you have to take into consideration that a lot of women traditionally were not allowed to receive educations until recently. Also, those that were educated were never taken seriously due to various social factors. Just to note, there was a woman who helped engineer the Eiffel Tower and she never received credit for it. As far as art goes, there does exist Kahlo.

  6. #6 Dave Munger
    September 25, 2007

    RPM:

    Yes, we’ll be getting to that…

  7. #7 Tlonista
    September 25, 2007

    @Jorge Gajardo Rojas: The preponderance of male painters and philosophers throughout history is entirely due to men’s and women’s traditional social roles. Historically speaking, women have been systematically denied civil rights, education, and the opportunity to pursue their own careers, which kind of gets in the way of being an Artistic Genius or Brilliant Thinker. It’s not a mystery.

    To bring this back on topic, it’s been postulated that the lingering influence of this institutional bias (as opposed to biological difference) is largely responsible for the paucity of women in math and science.

  8. #8 themissingy
    September 25, 2007

    I wonder what effect the difference in “gendered” toys makes on the future ability to rotate objects in three dimensions.
    I mean, pink ponies don’t exactly inspire thinking about 3-dimensional geometry the same way Lego sets do…
    Pointless anecdotal evidence: female, played with construction sets and pentamino sets the whole time including adult years; am reasonably good with 3-d shapes.

  9. #9 Blake Stacey
    September 25, 2007

    Denise:

    I knew that Sophie Germain did important work on elasticity and should rightly have been honored on the girder of the Eiffel Tower which commemorated famous mathematicians and scientists. However, she died too early (1831) to be directly involved with the design of the Tower. Are we thinking of the same person?

  10. #10 El Christador
    September 25, 2007


    When Lawrence Summers suggested that the reason there aren’t more women in the top academic positions in math and science is that they don’t have the aptitude for it, a firestorm was created that may have cost him his job as president of Harvard University.

    Pedantically, it was that he suggested it was possible that it might be due to innate aptitude. That they don’t have the aptitude is not disputed (you will recall the much-publicized report, maybe from the NAS, that came out afterwards, which was widely billed as a rebuttal to Summers, agreed that it certainly is the case that at the higher end of the aptitude distribution, women are underrepresented), it’s whether this is innate or due to social factors that is disputed.

  11. #11 El Christador
    September 25, 2007

    First, I should rephrase “That [women] don’t have the aptitude is not disputed” to “It is not disputed that women are underrepresented at the high end of the aptitude distribution” or “It is not disputed that high-aptitude women are rarer than high-aptitude men”.

    Since I assume someone will want a reference to support that, it’s from p.34 (in Chapter 2) of the NAS report “Beyond Bias and Barriers: Fulfilling the Potential of Women in Academic Science and Engineering (2007)”. They write

    It is precisely at this extreme tail of science and mathematics abilities that sex differences are most evident. For example, in a study of close to 10,000 talented 12- and 14-year-olds who had taken the SAT, the male:female ratio was 2:1 for those with SAT-M scores of at least 500; it was about 12:1 for those with scores of at least 700.b Such findings are often viewed as part of a pattern of greater variability in ability and achievement among men than among women. As Steven Pinker has so succinctly stated, when it comes to male abilities and achievement there are “more prodigies, more idiots.c”

    The report then goes on to say that this difference in the tails can’t be the reason for the greater participation for men relative to women in all science, engineering and math careers, because those people aren’t drawn from the top end of the aptitude distribution. But of course, Prof. Summers made quite clear that he was not talking about all such careers, but the extremely “high end” ones, such as professors at top-ranked schools. That is, the subsequent material in the report saying the variability hypothesis doesn’t explain the gap is talking about quite a different set of careers than Prof. Summers was. The report notes that the ratio in men’s favour appears to be decreasing i.e. the relative frequency of high-aptitude women is increasing with time, and hence they suggest the overrepresentation of men is due to social and not innate factors. But, as I noted, that is the question which is disputed, that there is currently relative overrepresentation of men at the high end of ability is not.

  12. #12 El Christador
    September 25, 2007

    Actually, on third thought, your statement

    When Lawrence Summers suggested that the reason there aren’t more women in the top academic positions in math and science is that they don’t have the aptitude for it, a firestorm was created that may have cost him his job as president of Harvard University.

    is probably fair. That is, the fact that the overrepresentation of men at the high end of aptitude (note: not innate aptitude!!) is not disputed by those who study the question has no relevance whatsoever to whether he would be attacked on that account. Most people who were complaining about what he said were not people who would be aware of what the research says. (Presumably because people who are not familiar with the research greatly exceed people who are in number.)

  13. #13 Tatil Sever
    September 25, 2007

    “When Lawrence Summers suggested that the reason there aren’t more women in the top academic positions in math and science is that they don’t have the aptitude for it, a firestorm was created that may have cost him his job as president of Harvard University.”

    Actually, I belive he said the innate ability in the tails “might” be the reason, but he also offered two more possible reasons. If I remember correctly, one of them was the possibility that women may be putting more value to having a more balanced life. What is so wrong about suggesting that there might be some subtle biological differences between the sexes? In any case, I think he was not popular at Harvard, so the faculty there jumped on this opportunity to bring him down.

  14. #14 laserboy
    September 26, 2007

    Actually, I belive he said the innate ability in the tails “might” be the reason, but he also offered two more possible reasons. If I remember correctly, one of them was the possibility that women may be putting more value to having a more balanced life. What is so wrong about suggesting that there might be some subtle biological differences between the sexes? In any case, I think he was not popular at Harvard, so the faculty there jumped on this opportunity to bring him down.

    You think the womb is a subtle difference?

    There is a big difference between “something innate in women” prevents them from becoming great mathematicians and “there is demonstrable difference in success rates between men and women mathematician.” The studies above seem in indicate visualspatio skills are important (no surprise there) and that they can be taught, which would indicate that it is our teaching methods at fault rather than biology.

  15. #15 Flo
    September 26, 2007

    .. that it’s possible to teach these visuospatial skills. Such a course has been offered at Michigan Tech for many years, ..

    Can someone give me a source here? I am really more interested in the course material, or type of exercises they do. A friend of mine is (self proclaimed) very bad at this, but would probably be interested in getting better. I insisted that it had to be learnable, and suggested her to draw (also because it’s fun).

  16. #16 Dave Munger
    September 26, 2007

    Flo,

    See comment #3. I believe that drawing/sketching is definitely part of the program.

  17. #17 Flo
    September 26, 2007

    re: #16

    Thanks, and sorry. I posted to fast, before completely parsing #3. Unfortunately the papers seem *awfully* hard to come by in Austria, but thanks nevertheless :)

  18. #18 Drugmonkey
    September 26, 2007

    “I am really more interested in the course material, or type of exercises they do. A friend of mine is (self proclaimed) very bad at this, but would probably be interested in getting better.”

    Easy and Fun.

    #1 LEGO building. the complicated kits especially.
    #2 video games. especially the scene/adventure/mapping type ones

    hey if it works for kids why not for adults…

  19. #19 agnostic
    September 27, 2007

    If you remove visuospatial skills and analogical reasoning skills, you’ve eliminated math — you can learn math without these things, but you could never contribute to the field.

    Also, the sex differences are tail differences (variance rather than mean).

  20. #20 feromon
    December 31, 2007

    female, played with construction sets and pentamino sets the whole time including adult years; am reasonably good with 3-d shapes.