What Scientists Learned by Eavesdropping on Thousands of People

The EAR can’t prove any of these theories—it can only listen. Mehl co-created it, in the nineties, to gauge who people talked to, how often they talked to them, and the kind of language they used. “We basically get an unobtrusive record of a person’s day as it naturally unfolds,” he said. The first version was a modified microcassette recorder; Mehl had to call participants in the morning to remind them to flip the tape. Now the EAR comes in the form of a smartphone app. As long as participants remember to keep their phones on them, it will passively document sounds in their lives. Researchers have used the EAR to listen in on postpartum women, couples, Americans after 9/11, and young athletes.

In April, I loaded the EAR app onto a borrowed Android phone. I wondered if the soundscape of my own life was quieting down—would I wind up recording a lot of silence? In the span of a week, the phone spent time on my desk, in my kitchen, at dinner parties, and in meetings with a contractor. Even though I record several hours of journalistic interviews each week, and my husband and I have a tradition of recording recaps of our travels when the memories are fresh, I felt slightly nervous about replaying the audio. The EAR exists because we aren’t fully aware of how we sound. What would it reveal?

In the twentieth century, many social scientists advanced the argument that measuring what happened in “real life” could unveil more than highly controlled laboratory experiments. In 1949, eight observers worked in shifts to generate data for “One Boy’s Day,” a report that documented every activity of a seven-year-old in Kansas. In the seventies, Mihaly Csikszentmihalyi, a psychologist recognized for naming the “flow state,” helped develop what came to be known as the experience-sampling method, in which research participants filled out questionnaires whenever a wristwatch or pager beeped. In the nineties, two other psychologists, Arthur Stone and Saul Shiffman, introduced a similar approach, the ecological momentary assessment (E.M.A.), which asked people to share how they felt or what they were doing throughout the day. Stone, the director of U.S.C.’s Center for Self-Report Science, told me that the resulting snapshots gave researchers an “understanding of what that person is really like.”

It’s not that people lie. Rather, in Smyth’s telling, it’s that we can’t say accurately what we did last month, or how we felt this morning. “When I’m asked to summarize my experiences, it tends not necessarily to reflect my actual experience, but more how I think my experiences are,” Smyth told me. Different psychological tools can document different aspects of life. The E.M.A. captures momentary feelings; other methods passively track physical movements or social-media use. (Most people say that they move much more than they really do.) The EAR listens. Susan Wenze, an associate professor of psychology at Lafayette College, emphasized that it does not capture inner experiences or feelings. It can’t say whether you’re lying or putting on a brave face. But it often leads to surprising findings.

In 2016, a study that used the EAR found that children’s asthma symptoms, such as wheezing, increased when they fought with their family members—an association that wasn’t as noticeable when families filled out daily diaries. Another study found that romantic partners rarely discussed breast cancer after one of them was diagnosed, except to work through logistical considerations such as appointment times and doctors’ credentials. A third one found that when people with rheumatoid arthritis or cancer swore around others they received less emotional support from friends, and their depression symptoms tended to worsen. Yet another review of EAR audio found that people who sighed frequently were not necessarily burdened by negative emotions.