Solid friendships can help buffer life's stress. iStockphoto hide caption

itoggle caption iStockphoto

When researchers at Weill Cornell Medical College scanned teenage brains, they found that the area that regulates emotional responses has to work harder to keep impulses in check. Courtesty Kristina Caudle/Developmental Neuroscience hide caption

itoggle caption Courtesty Kristina Caudle/Developmental Neuroscience

Drivers under 25 are more likely to send text messages and make calls behind the wheel. They're also less able to handle distractions while driving. iStockphoto.com hide caption

itoggle caption iStockphoto.com