Are teenagers too rational? That, at least, is the conclusion of a recent study showing that teens overestimate the riskiness of things like unprotected sex and drunk driving, yet choose to do them anyways:
A study by researchers at the University of California, San Francisco, found that teenagers were more likely than adults to overestimate risks for every outcome studied, from low-probability events like contracting H.I.V. to higher-probability ones like acquiring more common sexually transmitted diseases or becoming pregnant from a single act of unprotected sex.
“We found that teenagers quite rationally weigh benefits and risks,” Dr. Reyna said in a recent interview. “But when they do that, the equation delivers the message to go ahead and do that, because to the teen the benefits outweigh the risks.”
For example, she said: “The risk of pregnancy from a single act of unprotected sex is quite small, perhaps one chance in 12, and the risk of contracting H.I.V., about one in 500, is very much smaller than that. We’re not thinking logically; they are.”
I’m not sure I agree. First of all, a one in 12 chance of getting pregnant is not an inconsequential risk. I think you could easily make the case that rational people, even Bayesians, would still choose to wear a condom given those odds. Secondly, I think the “teens are too rational” theory contradicts recent findings about the teenage brain. The problem for teens is that the rational circuits of the frontal cortex are actually the last to develop. (The development of the brain recapitulates its evolution, so that, in general, the brain areas that were last to evolve are the also the last to develop.) While the have fully functional emotional brains, adolescents often lack the mental muscles to hold these emotions in check. A 2006 fMRI study by neuroscientists at Cornell, for example, demonstrated that the nucleus accumbens, a brain area associated with the processing of rewards (like sex, drugs and rock n’ roll), was significantly more active and mature than the prefrontal cortex, which helps us resist such temptations. In other words, teens have reckless sex and drink too much and drive dangerously because their rational brain is at a literal disadvantage. It can’t argue back against their impulses.
On a related note, I’ve recently been enjoying the DVD’s of My So Called Life, perhaps the greatest teen soap opera ever on television. The verisimilitude of the show is almost painful. (Did I really talk like Angela Chase, with all those ums and likes and maybes stuffed into each of my sentences? Yes, I did.) And the teens on the show definitely aren’t rational. (Well, perhaps Brian Krakow is an exception. His frontal cortex seems fully developed…)