Editor's note: The orignal online version of this story was previously posted.
We often hear that teens are irresponsible because their brains are immature. But, contradicting that idea, teen turmoil is completely absent in more than 100 cultures around the world [see “The Myth of the Teen Brain,” by Robert Epstein; Scientific American Mind, April/May 2007]. Nevertheless, neuroscience studies do indeed suggest that the gray matter in the frontal cortex of teens, as compared with adults, is not fully developed.
Now a study by neuroscientist Gregory S. Berns and his colleagues at Emory University adds a new wrinkle to the gray matter findings, reporting that teens who are risk takers and drug users actually appear to have a more developed brain than their conservative peers.
The Berns team assessed the risk-taking tendencies of 91 teens between the ages of 12 and 18 with a written test and a drug test. Then, using a relatively new MRI technology called diffusion tensor imaging, the researchers looked at the amount of white matter in the frontal cortex of the teens’ brains. White matter contains the protein myelin, which coats neurons’ spindly axons as they reach toward other areas of the brain. Myelin is important for efficient signaling between neurons, and it is known to grow considerably between childhood and adulthood.
The investigators found that engaging in dangerous behaviors was associated with increased white matter, a result directly opposite to the gray matter findings. One possible interpretation: people whose brains mature early might be more prone to engage in adult activities. But Berns suggests that the entire teen brain idea might be overhyped. “Nobody denies that the brain develops or that teens take risks,” he says, “but how the two observations got intertwined is beyond me.”
Developmental psychologist Laurence Steinberg of Temple University questions the significance of the new study. Other researchers have found a connection between increased white matter and reduced impulsivity, Steinberg explains, which could mean a reduced likelihood of risk taking—the opposite of the Berns finding. Renowned neuroscientist Michael S. Gazzaniga of the University of California, Santa Barbara, is more impressed. “So much for the much touted model of the teenage brain,” Gazzaniga says. “Back to the drawing boards again.”
This article was originally published with the title Risk-Taking Teens Have More Mature Brains.
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3 Comments
Add CommentI was a risk taker then and am still one 15 years after hitting 18. Bit more stressed and have some physical damaged now, but would be doing all the same stuff if that work thing were not in the way. Of course my line of work allows adrenaline to flow free.
Reply | Report Abuse | Link to thisPerfecly right. A child who keeps tethered to his mother's apron strings will have very little chance to succeed in a life that vociferates survival for the fittest. The child grows up like a sapling below the shade of a mango tree, turning a weakling day by day, until he finally lets go or suffers a breakdown.
Reply | Report Abuse | Link to thisBut a child who from his early years endeavours to have his way is genetically and hormonally armed with the drive to act and react rather than to be a passive beholder. I have also observed that children who are exposed to difficult family situations are more prepared for the problems in life than those who are spoon-fed and over-cajoled by their parents.
After all, the first impressions n life have a lasting overall effect in their daily doings.
"So much for..."? That's an irresponsible statement on the part of an expert in neuroscience. If we have lots of studies showing that myelination leads to LESS risk taking, and then ONE that shows the opposite, shouldn't we look more closely at the soundness of the outlier, rather than throw in the towel and say, "Well, so much for all that other evidence!"? Sheesh! It seems to me that a lot of researchers just cherry pick evidence that supports their own beliefs, rather than doing an unofficial meta-analysis and accepting what most of the evidence shows (or at least, what the BEST studies show).
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