Think of the stereotype of the female mathematician as the homely spinster, or the female high school student who opts out of math courses as early as possible, or the Barbie doll that says, “Math is hard!” The gender gap that exists in the field of mathematics has permeated our society and become entrenched in our culture. Unlike many such popularizations of psychological research, gender differences in the field of mathematics are persistent and tangible.

From Maccoby and Jacklin's (1974) work on the psychology of sex differences to Halpern's (2000) in-depth analyses of gender and cognition, the one consistent finding has been the performance gap in standardized tests of mathematics favoring males. Differences on mathematics tests are generally found to be one-third of a standard deviation or greater. For example, Willingham and Cole (1997) report the following standard deviation units for several tests of mathematics: 0.36 for the SAT – Mathematics, 0.25 for the ACT – Mathematics test, and 0.63 for the GRE – Quantitative. Differences in the same direction are found even when comparing scores for students in mathematical fields or for students who have taken the same math courses. The GRE – Mathematics subject test, for example, shows a male advantage close to one standard deviation (0.87) and Advanced Placement and achievement test scores show a similar, though smaller, gap (0.17 for Calculus AB, 0.20 for Calculus BC, 0.38 for Math 1 Achievement test, and 0.42 for Math 2 Achievement test).