More millennials are living with their parents

Number more than doubles 1980 figures

More Americans than ever live in multigenerational households, and the number of millennials who live with their parents is rising sharply, according to the Pew Research Center.

A record 57 million Americans, or 18.1 percent of the population, lived in multigenerational arrangements in 2012, Pew said in a study released Thursday. That's more than double the 28 million people who lived in such households in 1980, the center said.

A multigenerational family is defined as one with two or more generations of adults living together.

A sluggish job market and other factors have propelled the rise in millennials living in their childhood bedrooms.

About 23.6 percent of people ages 25 to 34 live with their parents, grandparents or both, according to Pew. That's up from 18.7 percent in 2007, just before the global financial crisis and recession, and from 11 percent in 1980.

For the first time, more young people live in multigenerational arrangements than do Americans 85 and older, measured in percentages.

Among the elderly, who frequently stay with their children because they need care, 22.7 percent lived in multigenerational arrangements in 2012, according to Pew. That's up from 21.9 percent two years earlier.

The share of millennials living with parents and/or grandparents jumped to 23.6 percent from 21.6 percent.

The number of multigenerational families soared mostly during the recession, which ended five years ago. It has continued to rise since then, though at a slower pace.