In anticipation of a December/January slowdown, we’re reposting some older writing for the benefit of new (and nostalgic!) readers. This piece originally appeared on Oct 17, 2009.

It comes up a lot in discussions of women in computer science, women who write code, women in open source. Eventually, someone brings up the fact that women score slightly lower on math tests. Clearly, they claim, this biological inferiority must explain why there are fewer women in math heavy fields.

It sounds like a compelling reason, and it gets a lot of play. Except, you know what? It’s a lie.

I’m a mathematician. I’ve looked at those numbers, I’ve read some papers. The research into biologically-linked ability is fascinating, but it simply isn’t significant enough to explain the huge gender gap we see in the real world. I used to do this presentation on the back of a napkin for people who tried to spout this misconception to my face, and I finally put it online:

Love it? Hate it? Learn something? Catch the Mathnet reference? Let me know.

Re-posting notes: one of the most common complaints about this slideshow was that the graphs aren’t perfect. You may wish to read this comment about the design choices I made when preparing this slide show. I periodically toy with the idea of putting together a follow-up presentation including some more recent research ideas regarding what causes the gap (e.g. recent research into stereotype threat) so if you have recent links to neat ideas, please pass them along!