While you may fantasize about leaving the grind behind and starting your own company, a new study shows thinking positive thoughts won't necessarily help you.

According to a study from the University of Bath and Cardiff University, pessimists tend to make better entrepreneurs.

By analyzing the startup and success rates of new business ventures, the researchers have found that optimistic people tend to over-estimate their business venture's potential, and that leads them to set up companies that have "no realistic prospect of financial success," according to the study.

Dr. Chris Dawson, Associate Professor in Business Economics at the University of Bath’s School of Management, said in a statement: "As a society we celebrate optimism and entrepreneurial thinking but when the two combine, it pays to take a reality check."

He adds, "Pessimism may not generally be seen as a desirable trait but it does protect people from taking on poor entrepreneurial projects."

Seeing as how 80% of people -- at least in the U.K., where the study was based -- see themselves as optimists, it's no surprise the researchers found that 50% of new businesses fail in the first five years.

The pessimistic findings were published in the European Economic Review.