When Do We Become Adults, Really?

In February, a pop-up science column, Annals of Inquiry, is appearing in place of Kyle Chayka’s column, Infinite Scroll. Chayka will return in March.

After my wedding, this past October, people started asking me: Do you feel different? Does life feel different? I hadn’t considered marriage the start of a new life stage, so I wasn’t sure how to respond. My husband and I had been dating seriously since soon after we met, and we already lived together. We got married, honestly, because it seemed romantic. But these questions made it sound like I had signed up for a transformation. Had I entered a new chapter without even realizing it?

People have a habit of dividing life into segments. The psychologist Jean Piaget argued that children go through four stages of cognitive development. Biologists describe turning points in the aging process as though they’re cliffs from which we’re doomed to fall; at roughly forty-four and sixty years of age, for example, distinct waves of molecular changes seem to increase our risk of many diseases. “Passages: Predictable Crises of Adult Life,” a 1976 best-seller by Gail Sheehy, warned of restlessness and infidelity among women starting at age thirty-five—incidentally, the age when I married. Last summer, I woke up to the good news that, according to economists, the midlife crisis is vanishing. Oh, wait: apparently young people are now unhappy enough that entering middle age seems rosy by comparison.

In my so-called married life, people close to me have grappled with what it means to get older. When my sister turned twenty-five, she felt increasing pressure to settle on a career, and she jokingly repeated a dubious bit of pop science: that her frontal lobe had finally finished developing. A friend turned forty, dumped his girlfriend of six years, and told me, with tears in his eyes, “It sounds stupid, but I never thought I would get old.” I was thinking a lot about where we all stood, so I consulted “Everybody Rides the Carousel,” a carnivalesque 1976 animated film inspired by the twentieth-century psychologist Erik Erikson. (Apparently, the seventies were a turning point in the study of turning points.)

Erikson, who was influenced by Freud, conceptualized eight life stages as tugs of war between opposing forces. Infants are torn between trust and mistrust, preschoolers between initiative and guilt. To capture stage six—young adulthood, i.e. one’s twenties and thirties—the film showed a cartoon man and woman metaphorically struggling with intimacy and isolation. They spoke to each other while wearing masks; they danced while swapping body parts. Stage seven, adulthood, spans roughly forty to one’s mid-sixties, and pits generativity—making long-lasting social contributions through art, children, or work—against stagnation. Age-wise, I was somewhere in stage six, and parts of it felt relatable. But none of these stages felt like a perfect fit.

As humans, we want our lives to be like building blocks that make sense when put together, Jeffrey Jensen Arnett, a research scholar at Clark University, told me. In 2000, Arnett coined a new life stage—emerging adulthood—to reflect life-style changes he had observed in people between eighteen and twenty-nine. He told me that another stage was proposed even more recently, in 2020: established adulthood. It is said to fall between thirty and forty-five, so I was smack in the middle of it. I wondered whether this stage would suit me better—and whether I needed one at all. Does it matter how we carve up a life?

Life stages are loosely based on undeniable transitions, for example, from childhood to puberty, and from puberty to adulthood. But the variation in nature has a way of defying categories. Last summer, in Glasgow, I saw a performance of “Caledonia” by the Changed Voices choir, a group of adolescents who had aged out of the youth chorus of the Royal Scottish National Orchestra. They were all teen-agers going through puberty, but were they really in the same life stage? Some of the singers still looked like baby-faced boys, whereas others were tall, with facial hair and defined jawlines.

The ancient Greek physician Hippocrates divided the lives of men into only four stages, a number that mirrored the four humors and the four elements. Solon, an Athenian statesman and philosopher, believed there were seven, most of which lasted seven years each, in keeping with the number of known planetary bodies in the solar system. (Adulthood, which started at forty-two, comprised fourteen years.) Arnett’s research also considers the life stages of Hindu men, which have historically been characterized by a shift in one’s roles, rather than by one’s age. The second stage begins when a man takes on household responsibilities in marriage, and the third—vanaprastha, which means “forest dweller”—begins when a man’s first grandson is born. “The ideal for this stage is to leave the bustle and distractions of daily life and enter the quiet and contemplation of the forest, at least in a spiritual sense,” Arnett wrote in 2017. In the Talmud, however, life after age twenty is carved up into decade-long intervals. Arnett, who is now in his sixties, told me that he’s drawn to the Talmudic view that a “special strength” emerges around eighty. This is more appealing than Solon’s model, which says that from sixty-three to seventy, a man will “depart on the ebb tide of death.”

Life stages became more standardized in the late nineteenth century, as mandatory schooling spread, and legal thresholds of adulthood were set in the twentieth century. In 1971, the Twenty-sixth Amendment instituted eighteen as the voting age in America, and, in 1989, the U.N. Convention on the Rights of the Child promised protections for people under eighteen. Meanwhile, retirement ages and pensions set parameters for the beginning of old age. Arnett developed the category of “emerging adult” after many twentysomethings told him, in the nineteen-nineties, that they didn’t identify as adults—they felt “off time,” he told me. Arnett thought that age-based life stages seemed increasingly outdated, given that people were, on average, getting married later, leaving school later, finding jobs later. The novel stage of emerging adulthood reflected modern life. “Some people, when I proposed it, said, ‘You can’t just invent a new life stage,’ ” Arnett said. “There was this assumption that they’re universal and they’re fixed. I didn’t see them that way.”

Neither does Clare Mehta, a psychologist at Emmanuel College who works with Arnett, and who came up with the term established adulthood. Mehta argued that psychologists had neglected this busy period when they had consolidated adulthood into a monolith. She saw people between thirty and forty-five trying to balance careers, marriages, and children for the first time. Established adults hadn’t yet reached the apex of their careers; some had young children at home, and, for most in this life stage, neither major health issues nor menopause had typically set in.

Mehta’s research, which is ongoing, includes interviews with people my age. During a two-hour Zoom call, she asked about my life. I didn’t want to define my stage in terms of discrete events such as buying property or exchanging vows, although I had recently done both of those things; after all, I could imagine doing those same activities in my twenties, just in a very chaotic and non-adult sort of way. Other ways I’ve grown seemed more important. These days, I better understand and manage my emotions. My interactions with other people seem less mysterious to me; I’m more patient and empathetic. In my family, I’ve adopted a more live-and-let-live attitude. I’m proud of progress in my career, even if I am far from settled.

It turns out that other established adults feel the same way. In 2024, Megan Wright, a postdoctoral research fellow at the University of York, worked with several colleagues to assess how more than seventeen