Don't do lead, kids! Nowadays everyone knows the dangers this substance poses to humans -- especially children in their formative years -- but back in the day, lead was everywhere. Ancient Rome was riddled with the stuff, using lead in everything from pipes, to smelting, to cutlery, pottery and wine. It's tough to know just how much lead the average person encountered, but breathing the lead-filled air alone may have dropped children's IQs by up to three points. In today's episode, Ben, Noel and Max discover a fascinating, controversial theory: that Rome didn't fall due to war and economic troubles... but instead, the empire toppled because everyone slowly became dumber and dumber.