Men do better on the math section of the SAT than women, many studies have reported. But maybe this isn’t because of differences in brain chemistry. Maybe what subject to excel in is taught in high school alongside quadratic equations and French.

Do schools teach kids how to “do gender”, that is, behave in certain ways depending on their biological sex? C.J Pascoe (Dude, You’re a Fag) writes that they do, by constantly reminding them what is gender-appropriate through everyday school rituals.

Take the dress code of River High, the high school Pascoe does research on, as an example of how schools emphasize gender differentiation. Although both boys and girls had to cover certain parts of their bodies, the parts in question were different. A girl had to cover everything until her bellybutton and a boy had to make sure his pants weren’t below his waistline. Another way of differentiating gender through dress is that boys and girls had different-colored graduation robes – girls wore yellow and boys wore black. These ways of differentiation are subtle – so subtle, in fact, that they become a part of everyday life and seem natural. Because they seem natural, they make gender differentiation because of social standards seem as undeniable as biological differences.

Similarly, heterosexuality or man-woman coupling is also made to seem natural and a model of how things normally are. One of the ways this was done at River High, Pascoe writes, was through the yearbook. The “superlatives” section of the yearbook always emphasized male-female pairings: the “best of” categories in each grade, such as “best-dressed” or “best-looking”, was not judged according to class or race but gender. Boys had their own winner of a superlative and girls their own, so that the boy with the best smile would not be selected from the entire student body but from all the boys in it. There was also a category for “best couple”. Coupling and gender therefore became a way of organizing students, just like class year.

In their interactions with students, teachers confirm these ideas. Pascoe writes about an elementary school teacher using the image of a heterosexual wedding to teach children grammar rules – the class puts on a mock wedding between the letter “Q”, which is designated as the groom, and the letter “U”, designated as the bride. A heterosexual wedding is unconsciously portrayed as universal and natural, right from elementary school.

In Pascoe’s book, this is called the “heterosexualizing process”. In this process children, starting from elementary school, can only be thought of as “normal” if they act according to the unofficial gender rules that they see around them – for example, girls play with kitchen sets and boys with trucks and if a boy plays with a Barbie he is not normal. Or girls do well in history and boys go on to become engineers. High school continues this process. Schools like River High, the high school cited in Pascoe’s book, not only emphasize gender differences through school rituals but also that heterosexuality, or man-woman coupling and all the institutions that follow, like marriage, is right and natural.

So the next time Sarah gets a lower grade than Tom in math, think about what they wore to prom.