Teenagers are programmed to take risks because they enjoy the thrill of dangerous situations more than others, British scientists said on Wednesday.
The findings may explain why adolescents engage in activities like drug-taking, fighting and unsafe sex.
"The onset of adolescence marks an explosion in 'risky' activities - from dangerous driving, unsafe sex and experimentation with alcohol, to poor dietary habits and physical inactivity," said Sarah-Jayne Blakemore of University College London's Institute for Cognitive Neuroscience, a co-author of the study.
She said these types of behaviors contribute to the so-called "health paradox" of adolescence, when a lifetime peak in physical health coincides with a period of relatively high health risks and death rates.
The researchers, whose work was published in the journal Cognitive Development, studied 86 boys and men between the ages of nine and 35, who were asked to play computer games where they had to make decisions to earn points.
After each game researchers measured the players' emotional responses by recording how satisfied or dissatisfied they were with the outcome.
They found that the onset of the teenage years marked a rise in how much enjoyment came from winning in a "lucky escape" situation. This could help explain why teenagers are more likely to take bigger risks, the researchers said.
"Understanding why adolescents take such risks is important for public health interventions and for families," said Blakemore.
The results suggest teenagers are good at weighing up the pros and cons of their decisions - unlike younger children - but take risks because they enjoy the thrill of a risky situation more than other age groups, especially when they have a lucky escape. The riskiest behavior was seen in 14-year olds.
A World Health Organization-backed study published last year found that 40 percent of adolescent deaths around the world are due to injuries or violence, with young men in low and middle-income regions such as Eastern Europe and parts of South America at particularly high risk.