Mathematics and Education

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Half of Women Do Not Have “Female Brains”

with 4 comments

. . . and half of men do not have “male brains,” according to research of Simon Baron-Cohen and his colleagues. See Table 1 of Goldenfeld, Baron-Cohen, & Wheelwright, 2005, Empathizing and systemizing in males, females and autism, Clinical Neuropsychiatry, 2, 338–345. More details are below.

[Update: If you’re looking for careful discussion of Ingalhalikar et al.’s December 2013 PNAS article on “wiring,” see Language Log’s post here.]

Although this finding is based on data collected for a study discussed in Baron-Cohen’s book The Essential Difference: Men, Women, and the Extreme Male Brain, the book does not discuss this possibility. Unfortunately, the title The Essential Difference suggests otherwise. Even worse, the finding is contradicted by the publisher’s description, which begins:

We all know the opposite sex can be a baffling, even infuriating, species. Why do most men use the phone to exchange information rather than have a chat? Why do women love talking about relationships and feelings with their girlfriends while men seem drawn to computer games, new gadgets, or the latest sports scores?

As evidenced by the Amazon reviews of The Essential Difference, this lack of clarity seems to have led to confusion about how the behaviors associated with the labels “male brain,” “female brain,” and “balanced brain” might actually be distributed among men and women.

Baron-Cohen hypothesizes that humans have two important classes of skills which he calls empathizing and systematizing. He and his colleagues asked a “random”* sample of people in the UK and Canada to respond to two questionnaires called the Empathizing Quotient and the Systematizing Quotient. These resulted in two scores for each person. There were 114 responses from men and 163 responses from women. These were compared with the scores of 47 people who had been diagnosed as having autism. The EQ and SQ scores were used to classify the 277 people in the non-autistic sample in five categories. Each classification had two names and an intended interpretation in terms of empathizing (E) and systematizing (S).

Name 1 Name 2 Interpretation
Extreme type E Extreme female brain E much stronger than S
Type E Female brain E stronger than S
Type B Balanced brain E and S about the same
Type S Male brain S stronger than E
Extreme type S Extreme male brain S much stronger than E

However, the responses couldn’t be classified by just comparing each person’s EQ and SQ scores. As with SAT scores, each person’s scores were normalized and compared with the entire score distribution. Unlike the process used to determine SAT scores, EQ and SQ score distribution was based on a small sample, namely that used in the study.

The classification was done in two ways, with similar results.

Result 1:




Extreme female brain



Female brain



Balanced brain



Male brain



Extreme male brain



The second assignment of scores to categories:




Extreme female brain



Female brain



Balanced brain



Male brain



Extreme male brain



Adding the percentages of women classified as having a balanced or male brain yields 46% (from the sum of 32 and 14) in the first categorization, and 51.5% in the second. Allowing for a slight amount of hyperbole, one gets “Half of Women Do Not Have ‘Female Brains.’” Similarly, about half of men are classified as not having male brains.

Baron-Cohen is careful to say in The Essential Difference, “The central claim of this book is only that more males than females have a brain of type S, and more females than males have a brain of type E” (p. 8). This idea is repeated toward the end of the book. “Hopefully, I have made it clear that when we talk about the female brain or the male brain, these terms are shorthand for psychological profiles based upon the average scores obtained when testing women as a group, or the average scores obtained when testing men as a group” (p. 183).

However, as evidenced by Amazon reviews, this message was not always received by readers.

Along with the misleading description of The Essential Difference from the publisher, other sources of confusion might have been the labeling of the categories. Using two names for each category seems like a bad idea. Descriptors such as  “male” and “female” conflate behavior and gender. Another contributing factor may have been the considerable overlap between the distribution of men’s and women’s scores for each questionnaire. The book did not discuss its implications.

* Footnote. According to p. 339 of the article, “114 men and 163 women were randomly selected from the general population.” However, the authors may have meant “stratified random sample.” Page 364 of a 2003 article which purports to describe the same sample says, “n = 278 normal adults (114 males, 164 [sic] females) taken from two sources: n = 103 were drawn from the general public in the UK and Canada, and represented a mix of occupations, both professional, clerical and manual workers, and n = 174 were drawn from undergraduate students currently studying at Cambridge University or a local ‘A’ level college in Cambridge. Students from a variety of disciplines were targeted.” Page 365 notes that these responses were 60% of a larger group. Thus, it appears that there may be sample bias due to the fact that 40% chose not to respond.


Written by CK

December 15, 2011 at 10:52 am

4 Responses

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  1. Well surely all this shows is that we are all on a male/female brain continuum, all having a variety of male/female characteristics within the incredible function of the brain. Where the male/female differences come in useful is understanding our partners. Sometimes behaviour is clearly male or female brain based and if these differences can be understood, although still frustrating, it may be possible to work out strategies between partners to avoid rowing about these things that cannot be changed, but may be accommodated..

    Clare Harding

    January 10, 2012 at 5:07 am

  2. Note that the study had some severe limitations:

    • the size of the sample in this study was very small.

    • the sample may be not have been random.

    • the sample was confined to people from England and Canada.

    • the findings were based on self-report (questionnaire responses).

    Many of these limitations are discussed in a November 2011 issue of Nature. According to this article, Baron-Cohen says “there is a problem that there are too few attempts at replication” of his studies and that he remains “open minded about these hypotheses [underlying the studies] until there are sufficient data to evaluate them.”

    One critic said of survey responses: “Whether those self-perceptions, as with any of our self-perceptions, are accurate is questionable.” Another said, “At the moment, he has people saying, ‘yes, I’m a person interested in details’, as opposed to actually observing them on tasks.”


    January 17, 2012 at 9:19 am

  3. Why not use neuroscience? Or can’t we use that?

    I agree, questionnaires assume that we:

    -know ourselves
    -tell the truth

    Humans have tons of cognitive (and cultural) biases.
    There’s some truth in it, but I hope neuroscience (and also evolutionary psychology) can give us the true answers.

    I like to know because I want to understand myself. I am vulnerable to psychosis (some consider this to be the extreme female brain). And I score high on the dark triad, all of them about a 75 percent score, yet a lot of dark triad traits do not apply to me: I’m not impulsive, I’m not promiscuous, I have a strong moral etc.

    Perhaps I’m ideology a dark person, not in nature. I feel little empathy to most of the people I know, I feel little empathy to most “friends”. Note the “” because I do not consider them true friends. I miss a emotional connection, and I know I am capable of that because I do feel that with one friend.

    Because of my psychosis I came in contact with psychologists and one thought I had autism.
    That’s not possible if the extreme male brain theory or the imprinted brain theory is true.
    The dark triad would be a much better explanation.

    A. Smith

    August 20, 2013 at 5:41 am

  4. This is a very timely comment because an article by Baron-Cohen and colleagues has been recently published on this subject. The article, “Biological sex affects the neurobiology of autism,” can be downloaded here.

    Note, however, that the Extreme Male Brain theory does not rule out the existence of women with autism. In fact, the study described in the new Baron-Cohen article included 30 women with autism. I’ve posted a short discussion of the article here.


    August 20, 2013 at 3:03 pm

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