The male gaze is a term for the way movies and other visual arts tend to appeal specifically to heterosexual men. In particular, women are objects to be viewed, and men do the viewing. I didn’t expect to need this term when I started to read a popular math book. But on page 2, I read the following sentence:

Every person in the room—from the preppy-looking thirty-something-year-old with spiked hair, taking notes in Chinese, and the young blonde with the tight blouse and the too-short skirt, to the jogger in baggy running shorts and damp T-shirt, and the rheumy-eyed octogenarian with herringbone coat stained by decades of chalk dust—knew that they were potentially witnessing a monumental milestone in a three-thousand-year-old legacy.

Let’s look at that sentence. The character whose gender is most identifiable is the “young blonde with the tight blouse.” (We assume the other characters are men, although they are not as clearly gendered.) Her appearance is both sexualized and described with explicitly judgmental language. When I read it, it was just one more reminder that women's bodies are subject to constant scrutiny, and we are always too sexy or too dowdy or too pretty or too ugly or too fat or too thin or maybe all six at once. I get this message a lot. I didn't need it from this book as well.

Later in the book, a sketch of a nude woman lying down facing away from the viewer is used to illustrate negative curvature, along with this description: "the saddle-shaped area on a woman's side above her hip." Here the woman is explicitly an illustration. She is even facing away, so we can see her, but she can't see us. In part this example is frustrating because there is no need to gender it at all. Almost all human bodies have negative curvature at the waist. It is more pronounced in a stereotypically female body than a stereotypically male body, but some men are curvier at the waist than some women. The example would have worked just as well with a clothed body of any or no gender.

I'm not identifying the book because it doesn't really matter. It's not the only math book with unexpected, unnecessary sexism in it. The troubling parts of this book are symptoms of a much larger problem. The author is probably a nice guy who genuinely wants to help women advance in mathematics. He was trying to liven up his narrative with some colorful descriptions, and he was simply oblivious to the message his descriptions sent. Nice guys—and nice women—are perfectly capable of thoughtless sexist actions.

One of the reasons I read so many popular math books is that a lot of people ask me for book recommendations for their math-inclined children and teenagers, especially their daughters, and I like to have a good feel for what’s out there.

I can't recommend this book to anyone for their daughters, sons, or non-binary children. How could I recommend that a young woman read a math book that reminds her on page 2 that she will constantly be judged based on her appearance, even when she is in a lecture hall trying to learn something? How could I tell a young man to look at his peers that way?

Perhaps I’m overreacting. It’s two tiny examples from a long book. Astrophysicist Katie Mack summed it up in a tweet that has stuck with me for two years:

“It’s just a t-shirt” “It’s just hello” “It’s just a magazine cover” “It’s just a TV show” It’s just every frickin’ aspect of life sometimes — Katie Mack (@AstroKatie) November 13, 2014

It's easy to think, "If you can't handle one less-than-perfect sentence in a book, you're too delicate to be here" or "Why are you so worried about this when there are people who have it so much worse than you?" But it really is relentless. One bumbling sentence is small on its own, but it's part of a sea of messages women and men receive starting when they are infants: women are looked at, men look.

I'm writing this post both because I'm frustrated and want to vent but also to encourage people to try harder. Whether you are teaching, writing, or just talking with your neighbor's kid about math, it is not impossible to think about whether your examples need to be gendered or whether you would write about a man the same way you write about a woman, especially when it comes to appearance. It is not impossible to think about the message a young woman would receive from this book and make it one that won't immediately alienate her. We can do better.