Old enough to know better by 26

The law may imply that you're a grown-up when you're old enough to vote, serve in the military or drink legally. But most Americans really think adulthood begins at age 26, according to a new study from the University of Chicago.

The study said most people don't consider a person grown up until they finish school, get a full-time job and start raising a family.

Tom W. Smith, who authored the study, said Thursday the results are a sign that society has accepted what researchers have long called an "extended adolescence."

Take marriage, for example. In the 1950s, the most common age for brides was 18.

"In 2003, when you hear about an 18-year-old bride, the first thing you say is, 'Boy that's unusual -- and boy, that person should've waited,"' Smith said.

According to those surveyed, the average age someone should marry was 25.7, and the age for having children was 26.2. Most respondents considered parenthood the final milestone needed to reach true adulthood.

The new data is based on findings from the university's 2002 General Social Survey, an ongoing poll of American adults that began in 1972 and which Smith oversees. Nearly 1,400 of those surveyed last year were asked to answer the questions about adulthood.

For categories other than marriage and having children, the average ages were: financially independent, age 20.9; not living with parents, age 21.2; full-time employment, age 21.2; finishing school, age 22.3; and being able to support a family, age 24.5.