The study, published in the Journal of Financial Economics, found extreme optimists work significantly fewer hours, save less money, are less likely to pay off credit card balances and are more likely to smoke than optimists.

"The differences between optimists and extreme optimists are remarkable, and suggest that overoptimism, like overconfidence, may in fact lead to behaviors that are unwise," study co-author Manju Puri, of Duke University, in Durham, N.C., said in a statement.

Puri and David Robinson analyzed data from the Federal Reserve Board's Survey of Consumer Finance -- a triennial assessment of financial and demographic information, which asks respondents how long they expect to live as well as demographic and health-related questions that can be used to determine a statistical life expectancy.

The researchers compared the statistically determined life expectancy to the self-reported life expectancy and categorized anyone who expected to live longer than their data predicted as an optimist. They labeled the top 5 percent of optimists -- who gave themselves 20 or more years than the statistics -- as extreme optimists.