BOSTON (TheStreet) -- There's a lot to be worried about these days. Banks are failing. Jobs are being shed. The hangover from last September's stock market crash still gnaws.

Along with traditional splits -- liberal vs. conservative, free market vs. regulation -- there can be an equally divisive, though less studied split among investors: optimism versus pessimism. Are better days ahead or is the economy a house of cards ready to topple?

Fidelity Investments has been taking a closer look at how investors' moods impact their financial decisions. In other words, are investors with pessimistic outlooks more conservative and better planners? Do optimists set clearer goals and go after them more aggressively?

In a recent study about couples and spending, the money manager asked participants how their psyches affected their views on saving for retirement. The answers proved enlightening and often contrary to the expected results.

"You might make the hypothesis that if someone is pessimistic about the future of finances that they would do a little more planning," says Joan Bloom, executive vice president of Fidelity Investments Life Insurance. "We actually found exactly the opposite. Optimists are actually planning more."

Only 15% of pessimists have completed a detailed income plan to help guide their finances in retirement, compared to almost twice as many optimists (27%). Pessimists were twice as likely (25% of pessimists, 12% of optimists) to invest with the goal of preserving money, and were willing to accept much lower returns. Optimists were more likely to invest with the aim of creating an equal balance of capital preservation and growth potential (39% of optimists, 25% of pessimists).

Both optimists and pessimists cited the 401(k) as the most important retirement product (15% of pessimists, 22% of optimists), followed by pension plans (13% of pessimists, 17% of optimists).

Bloom says the differences between pessimists and optimists lie more in how they save for retirement, rather than if they save. Optimists are more likely to have a plan and stick to it, and they are a little less likely to be conservative. They look at the big picture when it comes to retirement saving, which makes them better prepared to meet their goals, Bloom says.