The survey by the Pew Social & Demographic Trends Project also found that young people in the United States are more likely than their parents or grandparents to value wealth.

Those with the lowest incomes are among the most likely and least likely to rate riches as important. Among people with incomes of less than $20,000, 22 percent say becoming rich is very important, while 13 percent say it is not important at all -- in both cases about double the proportion of people with more than $100,000 a year.

Demographers say that may be because the low-income group is disproportionately either young or elderly.

One-fifth of those under 30 say being rich is very important and 42 percent say it is somewhat important. Those percentages drop with age.

The survey found that the biggest wish is for more free time -- with 67 percent saying that is their top priority.