Mark Perry is a sexist

…and he really doesn’t believe that he is, or understand why he is perceived to be one.

Here’s his column on how boys are, on average, and at the extreme, smarter than girls at math.  Well, that’s his conclusion based on test scores:

There has been a long-standing, and often very emotional debate about whether there are any gender differences in mathematical ability. If you have any doubts about how emotional and irrational the debate can get, just ask economist Larry Summers, who was forced to resign as president of Harvard (in part) for daring to suggest that there is statistical data showing that the variability of male math intelligence is different (greater) than the variability of female math ability. Specifically, Summers made this completely innocuous statement in 2005 that amazingly led to his ouster as president of Harvard:

It does appear that on many, many different human attributes – height, weight, propensity for criminality, overall IQ, mathematical ability, scientific ability – there is relatively clear evidence that whatever the difference in means-which can be debated – there is a difference in the standard deviation, and variability of a male and a female population. And that is true with respect to attributes that are and are not plausibly, culturally determined.

If one supposes, as I think is reasonable, that if one is talking about physicists at a top twenty-five research university, one is not talking about people who are two standard deviations above the mean. And perhaps it’s not even talking about somebody who is three standard deviations above the mean. But it’s talking about people who are three and a half, four standard deviations above the mean who are in the one-in-5,000, one-in-10,000 class.

Note that Summers wasn’t saying that men necessarily have greater mathematical ability than women, only that the variability (or standard deviation, the most common statistical measure of variability) of male math ability is greater than the variability of female math ability. Implication? More male than female math geniuses, but also more males than females with math aptitude far below average who are “math idiots” or who have severe learning disabilities.

Perry then goes on to cite new studies showing these testing differences in lots of countries, and even telling us which countries have the smartest boys, relative to girls:

 The mean score for boys on the math test for students in all 65 countries (477.5 points) was 8 points higher than the mean score for girls (469.5 points), see the middle bar in the chart. By individual country, boys scored higher on the math test than girls in 52 countries (statistically significant differences in 38 of those countries), with the largest differences in favor of boys in Colombia (25.5 points), Luxembourg (25.1 points), Chile (25 points) and Costa Rica (23.6 points). Girls scored higher than boys in 13 countries, with statistically significant differences in 5 countries (Qatar, Iceland, Jordan, Malaysia and Thailand).

Here are a few questions, Professor.

  • Check your assumptions.  How do you know that these tests reflect aptitude, and not the result of instruction?  I think pretty clearly the two must be confounded in these test results.
  • Did you check to see if the data is normal, or otherwise distributed?  Try making graphs showing the ACTUAL DATA (not the computed normal curves, unless you have a pretty good statistical basis for assuming normality).  The percentile differences are interesting, but not nearly as informative as actual data.
  • Why are there such large differences country to country?  To me, this says boys 38, tie 22, girls 5.  That’s not the same thing as the aggregate conclusion.  If there are country to country differences that swing that much either way, then isn’t it possible that it’s a teaching difference?  Or a testing difference?
  • And exactly what is your point?  Where are you going with this?  What is the result? Are you trying to justify an all male academia?  Because this does not lead to that conclusion.

Dude.  I don’t care what test results say.  I don’t care what the averages are.  Each person is an individual.  That’s why this is sexist – the only thing this tells me is that it’s possible that there aren’t gender differences, because they don’t exist in all countries, and they exist in both directions.

Not only that, but it also tells me that the distributions of current math abilities as tested are close between males and females.  There’s no reason that they shouldn’t both be represented at all levels of academia.

And in case you still don’t get it (I’m sure you don’t), try this explanation of racism from Jon Stewart.  The analogy applies.  Go to 8:30 in the video.

And in case you STILL don’t get it (I’m pretty sure you never, ever will), let’s try it this way:  Maybe you are correct, and you can break humanity into all kinds of groups, and test those groups, and determine that some groups are better at some test you give them than some other groups.  You can be 100% correct in that, YOU’RE RIGHT, and it JUST DOESN’T MATTER.  There are still individuals within each of those groups that are good at whatever you are testing for, and there is no action to be taken based on those test results.  Other than, to continue encouraging everyone.

It’s astonishing that, as a free market guy, you find this data meaningful.   All that tells me is that you are a sexist.

And this Venn diagram reinforces it:


This just seems kind of dickish, but its pretty easy to reconcile the two, to me.  If you believe that everyone should have the right to do what they want as long as they are not infringing upon others (i.e., supporting transgender stuff does not mean understanding it or agreeing with it), and the same opportunity to do so as everyone else (i.e. supporting men and women doesn’t equate to believing they are without differences), then both those top statements fall into those categories, with pretty good consistency.  I thought that was free market libertarianism.

Looking again, the statement about gender differences really doesn’t say that.  So he’s probably right.  But that group is probably very, vanishingly, small.  I mean, clearly there are significant innate gender differences, such as BODY ORGANS.  Duh.


1.  I’m pretty sure Mark Perry was looking to get a reaction like this blog post title.  So, you’re welcome.

2. The blog post was sexist because it defended the content and context of Larry Summers’ sexist statement.  Summers’ statement was sexist because it seemed to defend a status quo of unequal representation, and it came from a place of power in that context.  I don’t know if Mark Perry actually behaves in a sexist manner to individual women, or if his latent sexism causes problems for any women he interacts with, but there is no doubt that he lacks some understanding of what it is.




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