Why is it that some people smoke, despite the clear link between smoking and lung cancer? Why do others decide to drive after they’ve had too many cocktails?

Academic research has long shown that people with low self-control engage in riskier behaviors than do those with higher self-control. But what is the connection between self-control and risk? Are people with low self-control simply unable to stop themselves from risky behavior?

Not exactly. In a new study, researchers from Stanford and the University of Hong Kong found that people with low self-control look at consequences differently than those with higher self-control.

The research, by Stanford GSB associate professor of marketing Uzma Khan, University of Hong Kong’s Jayson S. Jia, and former Stanford GSB graduate student Ab Litt, describes how people perceive risk in two main ways: the probability that something bad will happen, and the consequences of those negative outcomes. And through a series of experiments, they found that those with low self-control focus more on the probability and pay less heed to the consequences.

For a real-life example, the researchers quizzed people on their health. They found that people with low self-control are more concerned if they are told their probability of contracting heart disease is twice as high rather than if they are told the consequences of heart disease are twice as bad as previously thought.

Khan, who studies behavioral judgment and decision-making, found the reverse to be true for people with high self-control, who tend to pay more attention to consequences and less to the probability of a risky outcome. This coincides with previous research showing that high-level executives pay less attention to the probability of negative outcomes. “Because they feel more in control, they think that outside odds don’t apply to them. Their behavior is, therefore, determined disproportionately by the consequence of the outcomes, such as the potential profits,” she explains.

But Khan cautions that the difference in perceptions of risk only applies to situations in which people have some agency or feel in control, such as catching a cold, which can be prevented by washing your hands. They don’t apply to risk in a situation like taking an airplane trip, in which the passengers have no control over the odds of a crash.

The Details

In a series of seven experiments, Khan and her colleagues commissioned online surveys to ask people to rate their perceptions of risk. Each survey taker answered questions to determine their level of self-control, and then they were presented with several dilemmas. In one regarding automobile safety, participants could choose between paying more for better airbags (focusing on consequences of an accident) or investing in better car brakes (focusing on probability of an accident).

“People low in self-control want the better brakes because they’re more concerned with the likelihood of an accident,” Khan says of the results.

Other survey questions examined:

• Heart disease: Do you take preventive medication (focusing on reducing probability) or sign up for good cardiac care insurance (focusing on reducing consequences)?
• Lung cancer: Do you switch to cigarettes with fewer toxins (focusing on reducing probability) or switch to a diet recognized to help the body fight cancer if it develops (focusing on reducing consequences)?
• Gambling: When rolling a 10-sided die, do you opt for a smaller payout with better odds (focusing on probability) or a bigger payout with less likely odds (focusing on consequences)?

Khan and her colleagues found that, in each example, those with low self-control preferred the probability-mitigating strategies over the consequence-mitigating strategies.

There are useful takeaways from the research in the areas of persuasive messaging and in designing laws, Khan explains. For example, the findings might explain why impulsive criminals are not swayed by severe consequences. “Impulsive crimes are going to be deterred more by the probability of being caught,” says Khan.

Think about ways to encourage safe sex. Teens tend to have lower self-control than adults, so if the focus is on teens, the message should highlight the probability of negative outcomes. “To teens you say the likelihood of contracting a sexually transmitted disease is 90%, rather than explaining the consequences – that you are going to get gonorrhea,” says Khan.