Donovan, who now works at BSCS Science Learning, an influential science-education nonprofit, is quick to point out that these are preliminary results. But his work raises some of the same questions as Morning’s: What happens when biology texts only mention race in the context of genetic difference? And can the way we teach the science of human difference actually shape students’ perceptions of race?

Teachers seem to be curious about issues like this—Donovan has presented at biology-teacher conferences, and he has collaborated with some teachers, including Strode. The National Science Foundation recently gave him and a collaborator a $900,000 grant for “exploring how knowledge of genetic variation and causation affects racial bias among adolescents.” When he recently put out a call for high-school classrooms to take part in an upcoming study, around 150 teachers asked to be involved. “People want to do it,” he says. “But they just don’t know how to do it.”

Meanwhile, textbook authors are cautious. “When solid research has something to say about topics like race, gender, and sexuality, I will try to touch on it if I can tie it directly to something that students will be able to understand based on their reading in the book,” said Mariëlle Hoefnagels, a biologist at the University of Oklahoma and the author of a textbook series published by McGraw-Hill Education, in an email to Undark.

She highlighted an essay in one of her books on skin color. “That essay explores the selective value of light pigmentation in low-UV regions and dark pigmentation in high-UV regions, without mentioning the word ‘race’ at all,” she wrote.

Ken Miller, a biology professor at Brown University and a co-author, with Joseph Levine, of Prentice Hall’s biology-textbook line, similarly said that the topic of race is not even mentioned in their textbook. “We have a very extensive section on human evolution and human origins,” he said. “We talk about the out-of-Africa model for the diversification of the human species … But we do not specifically go into anything that could be recognized as race.”

Miller and Levine are influential: Since 1990, they have sold more than 4 million books, and their publisher estimates that 40 percent of high schoolers in the United States use their books at some point. Over the years, Miller says, he and Levine have debated whether to touch on issues of identity. They have considered talking about the biology of sexual orientation, for example, but avoided doing so. One reason, Miller said, “is that there isn’t a science curriculum anywhere in this country that calls for the teaching of those subjects in a biology course.” And, he said, the science of sexuality is far from settled.

The two have considered talking more about the biology of racial difference, too. “Kids do have those kinds of questions. And Joe and I have asked ourselves, should we go into what little we know—it still is very little—what little we know about the genetics of race in our textbook? And we basically decided, no, race is still a social construction, it’s not a biological thing.”