The study results might explain why some people make certain bad choices. "For example, why is it people engage in behaviors the long-term consequence of which is worse for them?" Green said. "Why do you have that incredible chocolate cake right now when you're trying to lose weight, or you're trying to stay healthy, or trying to stay fit? One of the reasons is that being healthy, being fit, is a delayed reward; it occurs later. And the later it is, the less it controls your present behavior. It's discounted."
Similarly, gamblers "might be making bad choices because they're not taking the risk into account adequately," said Holt.
The researchers were not interested in gambling, per se. "The area of discounting may have important implications for a lot of different human behaviors — self-control issues, impulsivity, risk-taking, as well as gambling," Green said.
The study also argues against the longstanding view that impulsivity is a general trait that includes both an inability to delay gratification and a tendency to take risks.
The term "impulsive" is often used to describe people who "can't wait. They can't delay; they've got to have it now," Green said. "So they're willing to forgo something better that comes later in order to get something right away." But the term can also be applied to someone who doesn't take risks adequately into account. "They just act 'impulsively;' they don't think and consider all the risks," he said.
So if gamblers are thought to be impulsive because they don't adequately consider risks, then some researchers might argue that gamblers would also be impulsive in being less likely to delay.
"But what Dan found was that they weren't more impulsive with delay," Green said, "suggesting that this term 'impulsive' lumps together traits that might be different."
So the term "impulsivity" might not help distinguish between different disorders that are all currently classified as impulse-control disorders.
"What we would argue is that our study might give insight into different behavioral problems," Green said. "Some problems might be a combination of risk-taking and an inability to delay. Other problems might reflect difficulties with risk-taking; and other problems might reflect difficulties with the ability to delay. And the term 'impulsive' can't be used to describe all three of those."
Green, Myerson and Holt suggest that their research may lead to ways of assessing the likelihood that people will engage in self-harmful behaviors. Psychologists might be able to target those individuals and develop cost-effective interventions for those who are at risk, or assess their improvement as a result of therapy.
"If the individual understands the determinants of his or her behavior," Green said, "then the individual may be better able to control his or her own behavior.
