The XX Factor

Teachers Give Girls Better Grades on Math Tests When They Don’t Know They Are Girls

When teachers think girls are bad at math and science, it has an impact.  

Photo by Dawn Shearer-Simonetti/Shutterstock

When it comes to explaining why women are underrepresented in science, technology, engineering, and math, it’s not enough to point to discrimination in hiring, even though that is a real phenomenon. It’s also true that STEM fields have a “pipeline” problem, where not enough girls are choosing to pursue education and eventually careers in science and tech. New research suggests that part of the problem is that girls are being discouraged at very young ages from thinking of themselves as capable at math.

Victor Lavy of the University of Warwick in England and Edith Sand of Tel Aviv University recently published a paper for the National Bureau of Economic Research that suggests one reason girls do less well in math is because teachers expect less of them. Claire Cain Miller of the New York Times summarizes the study:

Beginning in 2002, the researchers studied three groups of Israeli students from sixth grade through the end of high school. The students were given two exams, one graded by outsiders who did not know their identities and another by teachers who knew their names.

In math, the girls outscored the boys in the exam graded anonymously, but the boys outscored the girls when graded by teachers who knew their names. The effect was not the same for tests on other subjects, like English and Hebrew. The researchers concluded that in math and science, the teachers overestimated the boys’ abilities and underestimated the girls’, and that this had long-term effects on students’ attitudes toward the subjects.

As University of Minnesota–Morris, biology professor PZ Myers said in his Science Blogs response to the study that these findings are particularly remarkable because math is supposed to be one of “those incredibly objective disciplines in which questions all have a right answer and a best method.” But according to this study, teacher expectations can have a strong hand in guiding how even math scores are assessed.

The reason this matters is that there’s a large body of research showing that teacher expectations can dramatically influence whether a student shows “innate” talent. In a 1966 paper, researchers Robert Rosenthal and Lenore Jacobson chose 20 percent of students, at random, and told their teachers that the students had performed remarkably well on a “test for intellectual blooming.” The belief that the kids were gifted, it turns out, made it so, as the kids randomly labeled that way showed greater gains on IQ tests than the kids that the teachers believed were just average.

That dynamic has been dubbed the “Pygmalion effect,” and it’s shown up in study after study: Just by believing that a student has an aptitude for something, the teacher makes it more likely to be true. So it matters quite a bit that teachers have unconscious beliefs that boys are better at math than girls, and we may be seeing the results in the many girls who might otherwise enjoy math getting discouraged and dropping out.

Clearly, fixing the “pipeline problem” in STEM is going to take more than a few pink toy microscopes. Few teachers likely think of themselves as biased against female students—after all, the teachers in the study were all women themselves—so rooting out the problem of bias is going to be a long, complex process. But admitting that unconscious bias exists and shapes responses to students is an important first step toward fixing the problem.