Most of us have to estimate probabilities every day. Whether as a trader betting on the price of a stock, a lawyer gauging a witness's reliability or a doctor pondering the accuracy of a diagnosis, we spend much of our time—consciously or not—guessing about the future based on incomplete information. Unfortunately, decades of research indicate that humans are not very good at this. Most of us, for example, tend to vastly overestimate our chances of winning the lottery, while similarly underestimating the chances that we will get divorced.

Psychologists have tended to assume that such biases are universal and virtually impossible to avoid. But certain groups of people—such as meteorologists and professional gamblers—have managed to overcome these biases and are thus able to estimate probabilities much more accurately than the rest of us. Are they doing something the rest of us can learn? Can we improve our risk intelligence?

Sarah Lichtenstein, an expert in the field of decision science, points to several characteristics of groups that exhibit high intelligence with respect to risk. First, they tend to be comfortable assigning numerical probabilities to possible outcomes. Starting in 1965, for instance, U.S. National Weather Service forecasters have been required to say not just whether or not it will rain the next day, but how likely they think it is in percentage terms. Sure enough, when researchers measured the risk intelligence of American forecasters a decade later, they found that it ranked among the highest ever recorded, according to a study in the Journal of the Royal Statistical Society.

It helps, too, if the group makes predictions only on a narrow range of topics. The question for weather forecasters, for example, is always roughly the same: Will it rain or not? Doctors, on the other hand, must consider all sorts of different questions: Is this rib broken? Is this growth malignant? Will this drug cocktail work? Studies have found that doctors score rather poorly on tests of risk intelligence.

Finally, groups with high risk intelligence tend to get prompt and well-defined feedback, which increases the chance that they will incorporate new information into their understanding. For weather forecasters, it either rains or it doesn't. For battlefield commanders, targets are either disabled or not. For doctors, on the other hand, patients may not come back, or they may be referred elsewhere. Diagnoses may remain uncertain.