To properly understand the behavior of an adolescent male human being, it helps to study the behavior of an adolescent male mouse. In a recent experiment, Temple University researchers separated mice into two groups: adults and adolescents, then further divided them into single cages or into groups of three, and then gave them all water spiked with ethanol.
The results were startling and yet not surprising at the same time: on their own, adolescent mice drank as much as their adult counterparts. But placed into groups, the equivalent of teenage mice drank twice as much as adults.
Despite being the most-watched and most-fretted-about demographic in society, no group is more dangerous - to themselves and those around them - than teenage males. The mortality rate for boys aged 15-to-19 is twice that of males aged one-to-four and more than three times that of boys aged 5-to-14. Sixteen year-old drivers, for example, are involved in three times more fatal crashes per mile than drivers age 20 or older.
There are two main causes of this: teenagers are more likely than others to make bad decisions on their own, but exponentially more likely to make bad decisions when in groups, and that the pleasure centers in the teenage brain are disproportionally large compared to other stages of life.
Laurence Steinberg is a psychology professor at Temple and one of the authors of the get-mice-drunk-and-see-what-happens study. He's also the author of Age of Opportunity: Lessons for the New Science of Adolescence and in it he writes (via the New Yorker):
This is especially the case when teen-agers get together. A teen driving with other teens in the car, for example, is four times as likely to crash as a teen driving alone. (The risk for adult drivers, by contrast, remains constant with passengers or without them.) This effect is often attributed to distraction or peer pressure; kids, the story goes, egg each other on, until, finally, they wind up in the E.R. But Steinberg, who has conducted all sorts of experiments on adolescents, both human and rodent, sees the problem as more fundamental. What matters is the mere presence of peers, or really even just the idea of them.
In one experiment, Steinberg asked subjects to play a video game that simulated ordinary driving. He found that teens took more risks when their friends were around—by, for instance, running yellow lights—whether or not they could communicate with them. In another experiment, Steinberg told his subjects that their actions were being watched by other adolescents, in another room, when in fact the other room was empty. The results were the same. Mice, for their part, can’t taunt other mice or call them wusses; still, the presence of peers is enough to stimulate risky behavior. Brain-imaging studies show that being watched by friends activates teens’ reward centers; this, Steinberg theorizes, primes them to seek out still more rewards, which leads them to do things like duct-tape malt-liquor bottles to their hands. “In fact, the recklessness-enhancing effect of being around peers is strongest when adolescents actually know there is a high probability of something bad happening,” he writes.
Steinberg writes that nucleus accumbens, the brain's pleasure center, reaches its peak size in the teenage years, and then shrinks from there. As a result, Steinberg writes, "nothing will ever feel as good as it did when you were a teenager." Add in that teenagers encounter many new life experiences for the first time, and you see why those teenage mice got so drunk. Or something like that.