20 percent of older women do not have children, compared to 10 percent in the 1970s.
"In recent decades, social pressure to play traditional roles has lessened in a broad variety of ways and there is more leeway for individual choice. This could play a part in lowering pressure for people to get married and bear children," said D'Vera Cohn, a co-author of the report. "Women have more options than in the past to build strong careers and to exercise the choice not to have children."
Cohn said another reason for the increase is that children are seen by some as less important for a successful marriage. A 2007 Pew survey found that 41 percent of adults said that children are very important for a good marriage, down from 65 percent in 1990.