From the mid-1980s until the late 2000s, the share of 25-to-34-year-olds living at home hovered in the range of 10 to 12 percent, according to Census Bureau data. That figure did start to rise when the Great Recession began, but it continued to climb well after the recession was over. It hit 13 percent in 2010, 15 percent in 2015, and nearly 17 percent in 2018. At the end of the 2010s, roughly 2 million more Americans in the 25-to-34 age group were living with their parents than at the beginning of the decade.

That suggests that, independent of the Great Recession, something broader has changed in how people embark on their adult lives. “More people are in education longer, and people marry and have their first child later than ever,” Jeffrey Jensen Arnett, a psychology professor at Clark University, told me. “You put those two things together, and you have more people either remaining home or moving back home than was true 40 or 50 years ago.” Arnett came up with the label emerging adulthood for the open-ended developmental stage lasting roughly from age 18 to 29, and wrote a book of the same name…

Public-health crises aside, the rise in the share of young people living at home in the past decade and a half has coincided with an important development in family life. “We were already shifting as a society toward stronger intergenerational bonds,” Fingerman said, pointing to research indicating that today’s young adults are in more frequent contact with their parents, and receive more guidance from them on emotional and financial matters compared with young adults several decades ago. In general, Fingerman said these strengthened connections represent a rewarding, welcome shift. They bring new closeness, though they can also bring up old tensions.