I used to do this back-of-the-napkin style presentation on whatever paper was handy when someone told me in person that women just weren't good at math, and that's why there were so few women in computer science. I'm not sure what possesses people to say stuff like that to female mathematicians, really. Anyhow, the point is that yes, there is some gender disparity in math skills, but if you do the math, it simply doesn't add up: those differences simply cannot explain why there are so few women in computer science (or in open source software, or in physics, or whatever). Many people misunderstand or abuse the information we have about gender and ability differences. Hopefully this presentation will explain what the data really says (which isn't very much).

1. How does biology explain the low numbers of women in computer science? Hint: It doesn't.

2. My name is Terri. I'm a mathematician.

3. I'm also female .

4. Nowadays, I work as a computer scientist. There aren't that many women in CS.

5. People like to say this is due to biological differences in math ability between men and women.

6. Turns out, people really suck at math.

7. Let me explain.

8. People claim the biological differences go like this: Rawr! I eat calculus for lunch! Math is hard. Let's go shopping! Men Women Rawr! I eat calculus for lunch! Math is hard. Let's go shopping! Men Women

9. That's not how it works Rawr! I eat calculus for lunch! Math is hard. Let's go shopping! Men Women Rawr! I eat calculus for lunch! Math is hard. Let's go shopping! Men Women

10. Ability graphs look more like this: Most normal people fall somewhere near the middle Only a few geniuses Ability # of people

11. When they hear men have higher math scores than women, people guess math is like this: Ability # of people Men Women

12. Which could explain why computer science is around 75% male... Ability # of people Men Women Must be at least this tall to write computer code

13. ...except that it's a lie. Lies, damned lies, and statistics, eh?

14. First, CS doesn't require that much math ability. When I was an undergrad, we drew the graph like this: Trees Computer Science Majors Slime Mould Moose Math majors

15. Heh.

16. But degree rivalry aside, I've been teaching CS for 7 years. You only need moderate math skills to code. Ability # of people Level needed to code

17. So that'd be something like this... Old Graph: Very few women New Graph: Lots more women Ability # of people Men Women Must be at least this tall to write computer code Dotted line is average for both genders

18. Except... Remember how I said the graph is a lie?

19. Ability # of people Men Women

20. The population difference looks more like this: Ability # of people Men Women

21. Don't believe me? Here's the graph from a paper on the subject. Hyde, J; Fennema, E; Lamon, S. “Gender differences in mathematics performance: A meta-analysis.” Psychological Bulletin. Vol 107(2), Mar 1990, 139-155.

22. So if we put that line back in... We should have nearly 50% women Ability # of people Men Women You must be approximately this tall to write code

23. Therefore, Biological differences do not account for the gender disparity in computer science. They can't. They just aren't that significant. Not even close.

24. Also... You know who really sucks at math? People who think biology explains why there aren't more women in CS.

25. Now you know. Thanks for listening.

26. This presentation was created by Terri Oda And is released under a Creative Commons Attribution-Share Alike license: If you want to use it in other ways, just ask: [email_address] Or email to let me know you liked it!