Dudes: Cramping your style since the dawn of time, and, now possibly cramping your career prospects. New research has found that being friends with the opposite gender in high school can lead to lowered GPAs—and that the effect is three times more significant for girls, especially in areas like math and science. Thanks, dudes! Stay cool this summer! Don’t go changin’!

The study, called “The Girl Next Door: The Effect of Opposite Gender Friendships on High School Achievement,” published in July at the American Economic Journal of Applied Economics by researcher Andrew Hill, pulled data on about 8,000 kids in some 80 schools from the National Longitudinal Study of Adolescent Health, which surveyed some 20,000 kids in grades 7 through 12 during the 1994-1995 school year (with some continued data collection through 2008).


Students in the study nominated their top five male and female friendships. Those whose nominations matched were considered strong pairs. Hill sussed out the strength of these particular friendships by looking at geographical distance, how much time they spent together meeting up after school, on weekends, talking over problems, or spending time talking on the phone. Hill also pulled related data on GPAs and grades in math, science, English, history, and more.

Writing at Fusion, Taryn Hillin notes:

Hill also looked at how well students got along with their teacher, how distracted they were in class, and whether or not they had been involved in a romantic relationship, based self-reported data. Females were more likely to report being in a relationship in the last 18 months.

After examining all the data, Hill found that—drum roll, please—opposite gender friends “are shown to have a negative effect on high school performance.” His findings held true even after controlling for other variables that can affect academic performance, including parent characteristics, home language, household income, family structure, and grade repetition. Ultimately, Hill says he’s confident the link is causal, not just correlational.

Interestingly, girls made better grades overall, and teenage boys in the study were more likely to nominate more girls as friends. But while everyone’s grades were more likely to suffer if they had more opposite gender friendships—as well as their ability to pay attention, or the likelihood of getting in trouble with the teacher—girls especially took a hit on this. All this has a way of validating those parents who refused to allow their daughters to date in high school, doesn’t it?


Of course, this isn’t the case for every kid with an opposite gender close friendship; it wasn’t the case for me. I was a good student and had lots of dude friends and boyfriends. Still, there were plenty of subjects, like math, wherein I was easily distracted—less by boys, actually more by my female friends. My best friend Leanne and I wrote so many notes during the first few weeks of geometry—a subject I already felt I wasn’t likely to be good at—that I never learned how to do a proof properly. But nothing distracted me from subjects I loved and excelled in.

Hill tells Fusion that either way, “Opposite gender friends are a distraction in class,” whether it’s because they lead to not paying as much attention, or not doing homework, or a greater possibility of getting a boyfriend, which also arguably leads to not paying as much attention or not doing homework.

Still: how relevant is this data for kids in high school today? Sure, girls were much more likely to be encouraged to lock a boyfriend down in high school in the mid-‘90s, and to make more of an emotional investment in one. But are today’s friendships still so fraught? Are mixed-gender friendships not more common now that millennials have (we assume) paved the way for cool chill buds? It’s worth noting that, in a look at the data following those original students through 2008, Hill found that those with more opposite gender friendships were less likely to have higher GPAs later, less likely to attend college, but more likely to be married (at a time when fewer people are getting married in general).

Assuming that there’s something evergreen to be pulled out here, I also wonder what other factors might drive certain kids to have more opposite gender friendships in the first place—which is intel outside of the study data. For one thing, you’d have to be less invested in rigid gender roles at a time when gender segregation is still the norm. If you’re best friends with a dude in high school, at least in my case, you were plagued by questions about why you aren’t really together—or it’s assumed that you actually are. How many of these teens reported their sexual orientation, I wonder?

But if, all underlying factors taken into potential consideration, the outcome about grades is still the same, the study supports Hill’s conclusion: that single sex classrooms are still a good idea in mixed gender schools, particularly if these opposite gender friendships cause problems with grades, but no other problems outside of school, such as drinking, smoking or teen pregnancy. One way to try this out would be through single-sex math and science classes, addressing the particular impact on those subjects.

An alternate conclusion: don’t sweat it. Maybe some people simply have more opposite gender friendships than others, just as some people are eminently more distractible. Being a teenager is, in a sense, one long, torturous sprint through Distraction City—and it’s just fingers crossed you don’t fuck anything up too much to keep you from a functional, employable adulthood. That any of us gets there just fine given every way we could be, and often are, derailed, is kind of amazing in itself.

Image via AP/Remixed by Tara Jacoby.