If you’re a female student at Arizona State University looking to up your GPA, the path is simple: Put down the razor.

Professor Breanne Fahs, who teaches courses on Women and Gender Studies, offered her pupils opportunity for extra credit if they subverted the expected gender norms around hair removal for a semester. For ladies, that meant no shaving their armpits or legs. For dudes, that means removing all their hair below their neck. Anyone opting to take the challenge had to document their experiences in a journal.

“There’s really no reason why the choice to shave, or not, should be a big deal,” Fahs told campus newspaper ASU News. “But it is, as the students tend to find out quickly.”

The results, students reported, were interesting.

“Many of my friends didn’t want to work out next to me or hear about the assignment,” said student Stephanie Robinson, who called the experience “life-changing.”

“My mother was distraught at the idea that I would be getting married in a white dress with armpit hair,” Robinson continued.

Another, Grace Scale, noted that one of her male friends compared her armpit hair to “the sludge in the bottom of the garbage can.”

Fahs’ project highlights something that’s rarely mentioned about hair removal: Our aesthetic preference for smooth legs and underarms for women is a relatively recent phenomenon. In fact, American women only began shaving their armpits around 1915, with the rise of sleeveless dresses. Shaved legs became de rigueur after the 1940s, thanks to rising hemlines and leggy pin-ups.

But too often, hairlessness on women—removing leg hair, armpit hair, and, yes, pubic hair too—is presented as a hygiene issue. It’s not. It’s a choice, and one worth thinking about, which is why the issue of grooming has become an entrenched part of the feminist debate.

Fahs’ experiment is part of the recent rise of an anti-grooming movement, one that questions the societal pressure for women to pluck, shave, and scorch off their body hair. Facebook groups and social media campaigns like Armpits4August encourage women to take a step back from the automatic belief that we all should be keeping ourselves bald below the neck. It’s an issue because it has to do with beauty standards, with the way that women are “supposed” to present themselves. What Fahs’ project did–and what many other women are doing–is questioning those norms, and challenging people to think about them, shaved pits or not.