By most physical measures, teenagers are the world's best drivers. Their muscles are supple, their reflexes quick, their senses at a lifetime peak. Yet car crashes kill more of them than any other cause. Auto insurance rates, based solely on statistics, are super high for teenage drivers and continue so until the mid-20s.

Now, a National Institute of Health study may help explain the statistics. It suggests that the region of the brain that inhibits risky behavior is not fully formed until about age 25.

"We'd thought the highest levels of physical and brain maturity were reached by age 18, maybe earlier—so this threw us," said Jay Giedd, a pediatric psychiatrist leading the study (Washington Post/LFF, Feb. 1).

This could help explain the temptation toward risky behavior for everything from driving to sexual activity to drug use.

Still, wisdom is a choice we can make. The book of Proverbs, written by Solomon to give "the young man knowledge and discretion" (Proverbs 1:4), says that "a prudent man sees danger and takes refuge, but the simple [or foolish] keep going and suffer for it" (Proverbs 22:3, NIV).