Nearly one in three Americans who grew up middle-class has slipped down the income ladder as an adult, according to a new report by the Pew Charitable Trusts.
Downward mobility is most common among middle-class people who are divorced or separated from their spouses, did not attend college, scored poorly on standardized tests, or used hard drugs, the report says.
"A middle-class upbringing does not guarantee the same status over the course of a lifetime," the report says.
The study focused on people who were middle-class teenagers in 1979 and who were between 39 and 44 years old in 2004 and 2006. It defines people as middle-class if they fall between the 30th and 70th percentiles in income distribution, which for a family of four is between $32,900 and $64,000 a year in 2010 dollars.