Not long ago, after a day of work, a colleague and I met for a friendly game of racquetball at our university gym. In the newly designed locker room, I began pulling off my shirt to change when he quickly stopped me: “You can’t do that here.” Undressing, it turned out, was now permitted only in small private stalls—which struck me as odd. This was a gym with a pool, where someone could go directly from a shirts-on locker room to a shirtless swim. But the logic was clear enough: The space had been redesigned as “universal,” for people of all genders. The locker room, once a place for casual and normative nudity, had quietly become a place where modesty was expected.

My Seattle gym is far from the only one to adopt the practice. Though public nakedness isn’t completely gone, many of the everyday spots where Americans once encountered unclothed bodies—locker rooms, school showers, public pools, bathhouses—have either vanished or shifted away from collective nudity. In 2017, Athletic Business, a trade publication for sports-facility design and management, reported that communal showers without curtains or dividers had virtually disappeared from new construction. This year, a different trade publication noted that one of the prevailing trends in locker-room design is privacy, a way to make “a diverse user base” feel comfortable.

It’s a striking reversal. For more than a century, the cultural norm in the United States was that nudity was acceptable—at least within same-sex environments. Over the past couple of decades or so, that idea has largely dissolved. This sort of nudity is so rarely discussed that we don’t really have vocabulary for it. The term nonsexual nudity feels inadequate, because for some, changing in a locker room could carry a charge of eroticism. Communal nudity is no better, evoking images of orgies or nudist colonies rather than once-routine forms of