That was the title of a WSJ article that you can read by clicking here.
Here are some key exerpts:
"Consider the FAAH gene. Roughly 25% of people with European ancestry carry the 385A allele of this gene. That tends to damp their brains' fear circuitry and to intensify their brains' reaction to the prospect of making money. Or take the DRD2 gene. Some 20% of Caucasians have an allele that can make them respond more intensely to gambles, even when no skill is involved."
Some people have brains that "crave the immediate gratification of a quick profit. "Controlling this kind of impulsive response to reward," says Dr. Hariri, "is crucial to success in many aspects of life" -- like investing, where impatience often lowers returns.
"Perhaps 20% of the variation in risk-taking among individuals is genetically determined; the rest comes from our upbringing, experience, education and training."
"But during scary times like these, says Dr. Hariri, "environmental stresses can play a critical role in unmasking any underlying biases determined by your genes." In other words, bear markets give nature the upper hand."