Oh to be young again? Not so fast, says a new study that found that older Americans tend to be happier than younger ones.

The University of Chicago study also found that baby boomers aren't as content as other generations, blacks are less happy than whites, women are happier than men, and as people age, their happiness increases.

"Understanding happiness is important to understanding quality of life. The happiness measure is a guide to how well society is meeting people's needs," study author Yang Yang, an assistant professor of sociology, said in a prepared statement.

The study was based on data from the General Social Survey of the National Opinion Research Center at the University of Chicago. Yang charted happiness across age and racial groups and found that among 18-year-olds, white men are the happiest, with a 33 percent probability of being very happy, followed by white women (28 percent), black women (18 percent) and black men (15 percent).

But curiously, those differences vanish over time. Black men and black women have slightly more than a 50 percent chance of being very happy by their late 80s, while white men and white women are close behind.

The increase in happiness with age is consistent with the "age as maturity hypothesis," Yang said.