Here's TIME's account:
"Relative to adults, adolescents engage more in unknown risks than they do in known risks," says Agnieszka Tymula, a postdoctoral student at New York University and the lead author of the study, which was published in the Proceedings of the National Academy of Sciences. Teens, it seems, love the unknown.
They may get lost in the details about specific risks and overly focused on possible rewards, while ignoring the overall "gist" of the problem — i.e., the ultimate consequences. In the case of unprotected sex, for example, even if the odds of contracting HIV are low, a bad outcome would be irreversible. Unlike teens, adults tend to focus on the end result and the consequences.
In other words, teens are cool with not knowing what's going to happen. Therein lies the risk.
Some genes predict risk-taking.
Kellogg management professor Camelia M. Kuhnen has found that a gene called DRD4 — which regulates hormone levels in the reward center of your brain — predicts whether you're likely to become a pathological gambler or a risk-loving stock market trader.
"If you carry the long version of DRD4, you tend to take about 25% more risk in your portfolio than other people," she tells Marketplace.
People who like to stay up late do riskier things.
Psychologists have fun words for being an early-bird or a night-owl: morningness and eveningness, respectively.
According to one Stanford study, people with a high degree of eveningness seek sensations, are more impulsive, and — you guessed it — take more risks. Although it might also be explained by sleep deprivation.
A follow-up University of Chicago study found that the correlation held for evening-oriented women, but not men.
If you're used to taking risks, you'll keep taking risks.
In his book "The Click Moment," Frans Johansson tells the story of the Cypres device, which was designed to help keep skydivers from dying.