In her seminal work The Managed Heart: Commercialization of Human Feeling (1983), the sociologist Arlie Russell Hochschild described a workplace practice known as “emotional labor management.” Hochschild was studying the extreme kinds of “emotional labor” that airline stewardesses, bill collectors, and shop assistants, among others, had to perform in their daily routines. They were obliged, in her words, “to induce or suppress feeling in order to sustain the outward countenance that produces the proper state of mind in others.” In the case of airline stewardesses, the managers and human resources staff of the airline companies relied on reports from passengers or management spies to make sure that stewardesses kept up their cheerful greetings and radiant smiles no matter what.

The stewardesses Hochschild studied were working under a regime of “scientific management,” a workplace control system conceived in the 1880s and 1890s by the engineer Frederick Winslow Taylor. Workers subject to such regimes follow precise, standardized routines drawn up by managers and undergo rigorous monitoring to ensure that these routines are followed to the letter. Taylor’s practice is often associated with such factory workplaces as the early Ford Motor plants or today’s Amazon “fulfillment centers,” where workers must perform their prescribed tasks on a strict schedule.

Hochschild showed that regimes of scientific management could be applied virtually anywhere. Her airline company managers aspired to control every aspect of their employees’ emotional conduct. What kept them from doing so was that they weren’t actually present in plane cabins during flights and so had to rely on haphazard reporting to confirm that the stewardesses were always behaving as they should. But in the twenty-first century, new technologies have emerged that enable companies as varied as Amazon, the British supermarket chain Tesco, Bank of America, Hitachi, and the management consultants Deloitte to achieve what Hochschild’s managers could only imagine: continuous oversight of their workers’ behavior.

These technologies are known as “ubiquitous computing.” They yield data less about how employees perform when working with computers and software systems than about how they behave away from the computer, whether in the workplace, the home, or in transit between the two. Many of the technologies are “wearables,” small devices worn on the body. Consumer wearables, from iPhones to smart watches to activity trackers like Fitbit, have become a familiar part of daily life; people can use them to track their heart rate when they exercise, monitor their insulin levels, or regulate their food consumption.

The new ubiquity of these devices has “raised concerns,” as the social scientists Gina Neff and Dawn Nafus write in their recent book Self-Tracking—easily the best book I’ve come across on the subject—“about the tremendous power given to already powerful corporations when people allow companies to peer into their lives through data.” But the…