LONDON (Bloomberg) ? ?Functional psychopaths? make the best investment decisions because they can?t experience emotions such as fear, a study by researchers at Stanford Graduate School of Business showed.

Fear stops people from taking even logical risks, meaning those who have suffered damage to areas of the brain affecting emotions, and can suppress feeling, make better decisions, the report showed. The ability to control emotion helps performance in business and the financial markets, the researchers found.

?Many CEOs and many top lawyers might also share this trait,? Antoine Bechara, a professor of neurology of the University of Iowa, said in a statement on the Stanford Graduate School of Business Web site. The study was carried out by Stanford, Carnegie Mellon University and the University of Iowa.

The participants in the study were given $20 to play a gambling game. At the beginning of every round, they had to decide whether to risk a $1 dollar stake on a toss of the coin, for a $2.50 return if they won.

While any player could decline to take part in a round, the financially ?logical? approach to the game was to participate at each stage because the ?potential return? outweighed the risk of loss, according to the research.

Brain-damaged players took this approach. They finished on average $3 richer than the others and invested in 84 percent of the rounds, compared with 58 percent played by the rest, who let ?fear? govern their decisions, the study showed.

The results help to explain the ?equity premium puzzle,? or why more people invest in bonds than stocks, when equities historically offer a higher average return, the report said.

?Investors are not behaving in their own best financial interest,? co-author Baba Shiv of the Stanford Graduate School of Business said. ?All research suggests that, even after taking into account fluctuations in the market, overall people are better off investing in stocks in the long term.?

Many successful investors may be so-called ?functional psychopaths? because they lack or can suppress emotions, according to the study.

Still, Shiv said emotions aren?t all bad. Those who can?t experience feelings tend to make ?disadvantageous? social decisions, losing their jobs and their friends, the report said.