“Even for adults, it is difficult to recognize faces in masks,” says Changhong Liu, a psychologist at Bournemouth University, in the U.K., who studies face recognition. People process faces holistically, he told me, taking in all the features in combination—which is impossible when some of those features are obstructed by a mask, or even sunglasses. And until about age 14, children are still developing their facial-recognition skills.

Some psychologists and educators worry that such impairment in facial processing can lead to a spate of challenges with socialization and communication. Kids may find reading people’s emotions through masks particularly difficult. And for children who are meeting new classmates for the first time while masked, recognition difficulties can slow down the getting-to-know-you process and, in the long run, hinder the development of trust. England opted not to require children to wear masks in elementary school, at least for the time being; according to The New York Times, both the Conservative and Labour Parties are concerned that masks make communication harder for kids. The World Health Organization also recommended that schools weigh potential “psychosocial development” concerns when deciding mask requirements for children ages 6 through 12.

Still, we know that masks reduce the spread of COVID-19. And though the benefits of mask mandates in schools continue to be debated, the reality is that many school systems have decided—reasonably, to my mind—to institute them for young children. The good news is that teachers and parents can help kids work through any social and emotional obstacles that masks present. Judith Lowes, a psychology researcher at the University of Stirling, in Scotland, who studies children and face perception, told me that people with face blindness—a diagnosable condition in which people struggle to remember and differentiate faces—often use other cues to identify people, such as clothing, mannerisms, or voice. “Quite commonly,” she said, “people use shoes.”