One afternoon several years ago, Emily Martin, a professor emerita of anthropology at N.Y.U., filled out a personality questionnaire through an app on Facebook called This Is Your Digital Life. This was long before the app’s creator, Aleksandr Kogan, was accused of using it to harvest information from more than fifty million Facebook users and sharing it with the consulting firm Cambridge Analytica. (The firm allegedly offered that data, in turn, to clients, including Donald Trump’s Presidential campaign.) Martin, a founder of the anthropology of science, scrutinizes scientific language and practices like other ethnographers pore over kinship diagrams. She regarded the personality quiz as a semi-relevant diversion while she immersed herself in a long-term field-work project concerning experimental psychology. She’d been drawn to the subject by the work of cognitive neuropsychologists, who put human subjects through controlled experiments in laboratory settings, testing how their brains process cognitive tasks. These labs frequently generate headline-grabbing research about supposedly universal psychological traits—that people who are more analytical are less likely to believe in God, for instance, or that we tend to see impulsive people as more honest. Martin wanted to understand how this research is done and whether the scope of experiments was changing with the advent of cheap and bountiful behavioral data, which we all shed, often unknowingly, in every one of our interactions online.

Getting research access to actual labs proved difficult, so, for a couple of years, she got her feet wet as a test subject, participating in more than fifty experiments. Many of them involved completing a simple task on a computer, then doing it again after having her emotional state altered—by being shown a disturbing picture, for example. She didn’t exactly blend in: she’s in her seventies, while most of the other participants were undergraduates, attracted by easy cash or free food. Eventually, one of the psychologists Martin met took an interest in her project and made helpful introductions. She was soon embedded in three labs: one in the Bay Area, one in Baltimore, and one in New York. She sat in on meetings, assisted with experiments, and developed relationships with principal investigators and graduate students. This is the slow-burn process that Martin’s fellow anthropologist of science Paul Rabinow calls “observing observers observing.” She wasn’t there to muckrake but to grasp what happens when the object of laboratory study is not a molecule or a rat but a human being.

Martin’s field work at the New York lab is now complete, but, in the spring, she paid a social visit, and I joined her. I was a graduate student of Martin’s at N.Y.U., but I hadn’t seen her in years. The lab is not far from the Upper West Side apartment she moved to with her husband, a retired biophysicist, and two unusually affectionate cats, after retiring from teaching, in 2017. Her hair is white and her gait a little cautious, but her smile remains youthfully impish. At the lab, the researchers seemed glad to see her, and Martin was clearly familiar with every inch of the place. When I admired a Japanese print on the wall, she told me that it had been selected for its resemblance to event-related potentials—the electrical brain waves made in response to specific cognitive stimuli. These are measured with electrodes placed against the scalp that amplify the faintest electrical brain signals. “Bald people are the most difficult subjects,” a researcher explained, holding up a skullcap through which needles would be lightly tapped. “They have more sweat glands, which interferes with conductivity.” Martin’s eyes lit up at the detail.

Anthropologists love to examine the sorts of tools that are taken for granted by those in the trade but are regarded as exotic by non-specialists. In a locked room at the lab was an expensive new eye-tracking technology, which measures gaze direction and changes in pupil size as subjects respond to prompts on a screen. “Your eyes index what’s going on with you internally, your emotional state, without you saying a word,” a researcher said. Another tool that fascinates Martin is the International Affective Picture System, which was developed at the University of Florida. The I.A.P.S. provides normative ratings of emotional responses to more than a thousand photographs. (These are shared for free with scholars so long as they don’t publish or distribute the images—their value as “standardized” stimuli depends on them remaining unfamiliar to the general public.) The ratings for each image are based on the responses of a hundred University of Florida undergraduates—an image of a floppy disk has a moderately high rating on the scale of pleasant to unpleasant, for instance, perhaps owing to nostalgia, while that of a grieving woman is low. Martin scrolled through some of the images for me on her laptop: snakes eating frogs, men lifting weights, crotch shots, old ladies with birds on their heads.

Martin’s freedom as an outsider to ask “naïve” and probing questions encouraged the psychologists to open up, gradually, about orthodoxies or inconsistencies in their work. One researcher said he was troubled that experiments were always designed around brief exposure to stimuli. “What would happen,” he mused to Martin, “if we lengthened the time the stimulus was exposed?” A junior researcher expressed frustration that there’s virtually nothing in the published literature about what happens after an experiment is completed, when volunteers, who may have been assigned a task that was designed to make them feel stupid or upset, are debriefed.

While she’s in field-work mode, Martin is always alert to what she calls these “ethnographic moments.” Even the smallest action or fragment of speech, she believes, can be a useful clue to the mostly invisible wider cultural assumptions that shape how research is done in any specialized field. She observes and collects these fragments, hoping that, later on, she’ll be able to find connections between them and make better sense of a scientific world view that is fascinatingly foreign to her.

Doing ethnographic field work in one’s own culture—and in non-traditional sites like laboratories—is an accepted practice today, but it wasn’t when Martin was introduced to anthropology, as an undergraduate at the University of Michigan, in the sixties. She went there intending to major in chemistry, but her roommate brought her to an ethnomusicology class, where the professor explained that Japanese Noh music was not structured around harmony or mechanical rhythm but around an elastic pattern. “No conductor, but breathing together,” she recalls him saying. Martin was hooked. “It’s actually the perfect analogy for what happens in field work,” she told me. “Noise to music via seeing things from another culture’s point of view.”

She has since realized that there was a deeper reason for her attraction to anthropology. “It is a version of naming the elephant in the room when I was growing up,” she said. She was born in Birmingham, Alabama, near the end of the Second World War. Her father had been posted to the Pacific theatre, and she didn’t see him until she was two. He returned profoundly disturbed by his war experience, and he was sexually inappropriate with Martin throughout her childhood. “My dad’s behavior was a huge problem but never spoken of. My symptoms of distress were blamed on anything else—a high fever, growing pains. To see the obvious and not be able to identify it was awful.” Her mother, in what Martin now thinks of as a “rescue gesture,” sent her to board at the Kingswood School in Cranbrook, Michigan, which she remembers as a wonderland. “Anthropology allows me to see things that might be obvious but usually remain hidden, in a variety of settings, and put them into words,” she said. “What a relief.”

She went to graduate school at Cornell and did her earliest field work in Taiwan, gathering villagers’ views on hepatitis during an epidemic of the disease. It was only years later, when she was pregnant with her second daughter and teaching in a new anthropology department at Johns Hopkins, that she began to think about doing field work in America. Every few months, she and a fledgling group—Susan Harding, who was studying Jerry Falwell’s megachurch in Lynchburg, Virginia; Harriet Whitehead, who was doing research on Scientology; Lorna Rhodes, who was writing about the psychiatric clinic in which she worked—met at Martin’s Baltimore row house, “trying to figure out how in the world you do anthropological field work in your own culture.” At childbirth classes, Martin tentatively interviewed other pregnant women; she scoured textbooks on obstetrics and gynecology. She began to see that women giving birth “were being held to standards of production, time management, efficiency” analogous to criteria in manufacturing. The language used about menstrual discharge in textbooks was that of the “ruined debris of failure”; the post-menopausal body was described like an “outmoded factory.” Yet the lived experience of the women with whom she was spending time often contested these medical pronouncements. She wrote a book, “The Woman in the Body: A Cultural Analysis of Reproduction,” which considered how a society built on other principles might value women’s bodies differently.