It's that time of year again. The back to school ads have started popping up all around us. And, while students are likely ignoring the signs that the school year is quickly approaching, most parents are counting down the days until the bell rings once again.

Back to school means another year of learning, growing, and expanding of young minds. New research suggests, however, that this learning can be significantly stunted for female students when they are aware of stereotypes impugning the or ability of their .

Psychologists have known for some time that when people are aware of negative stereotypes about the racial or gender groups to which they belong (e.g., "African Americans are not very intelligent" or "girls can't do math"), their performance on important tests can suffer. This phenomenon, known as stereotype threat, may help explain racial and gender gaps on standardized tests ranging from the SAT to AP Calculus tests. Now research shows that these negative stereotypes don't just jeopardize performance on tests, they actually shut down learning in the classroom.

In a study published late last month in the Proceedings of the National Academy of Sciences, Dr. Robert Rydell and his Indiana University colleagues asked a group of college-age women to perform a visual perception task. Before the task, some women were reminded of well-known stereotypes about women's subpar math and visual processing abilities (i.e., they were put in a stereotype threat situation). Other women were told nothing at all.

The task involved visually searching for a specific Chinese character in the middle of other distracting Chinese characters. Women were first shown the Chinese character they would be looking for (i.e., the target). Then, a display of several characters appeared. The goal was to indicate - as quickly as possible - whether the target was indeed in the display (which occurred about half the time).

Usually, as people learn this visual perception task, their ability to detect the presence of the target gets better and better. Eventually, people no longer need to search effortfully through the display. The target just "pops out" at them. Sure enough, this popout happened for women who were not reminded of negative stereotypes regarding their math and perceptual abilities. In contrast, women faced with the stereotype didn't really learn how to do the task at all.

One might wonder whether women under stereotype threat did learn, but just didn't show it. To test this, the researchers did something rather clever. Following the visual perception task, all of the women were shown two colored patches and asked to choose the patch with the greater color saturation. Superimposed on the patches was the target Chinese character the women had previously learned to search for. If people have learned to recognize these target characters, then superimposing them on the colored patches should slow down decisions about the patches' color saturation. This is because when you have spent a lot of time learning to recognize characters, objects, whatever, they pop out at you, even if you are not looking for them. Only women who were not reminded of negative gender stereotypes showed this slowing.

Dr. Rydell has work forthcoming showing impaired learning in math as a function of awareness of negative gender stereotypes as well. As it happens, women reminded that "girls can't do math" learn less in math lessons. These women have difficulty memorizing math rules and thus learn fewer mathematical facts and procedures than women who are not faced with the gender stereotype.

Although the above mentioned work was conducted with college students, it's easy to imagine how stereotype awareness in the early grades could put some girls on a slower learning path for good. A few months ago, my colleagues and I found that even as early as 1st and 2nd grade, students often endorse the stereotype that "boys are good at math and girls are good at reading." Importantly, when girls endorsed this stereotype, they showed less math learning across the school year.

Where do these stereotypes come from? We found that one source was the girls' female teachers. The more a teacher was about her own math ability, the more likely girls in her class endorsed the stereotype that "boys are good at math and girls are good at reading." And, when girls endorsed this stereotype, they showed less math achievement by school year's end.

So, as we think about the start of another school year, it is worth recognizing some of the factors that might slow down students' learning in the classroom. Interestingly, it has been shown that teaching girls that stereotypes about gender and math are not true and providing them with facts to back up this assertion, helps to curb the impact of negative stereotypes on performance. Of course, this tactic may not be very effective if female teachers, through their own math anxieties, are modeling commonly held gender stereotypes to their students.

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