In North Korea, young Kim Jong Eun will test age-old reliance on maturity By Marc Fisher, Published: December 23 At 28 or 29, Kim Jong Eun, the presumed new leader of North Korea, will be the youngest person ever to have authority over a nuclear arsenal. At that age, neuroscientists say, the brain is still in the final stages of development. Developmental psychologists say thereÂ’s a good reason that AmericaÂ’s Founding Fathers set 35 as the minimum age for a president: People younger than that just donÂ’t have the experience or skill to deal with complex decision making. Historians warn...