Plastic shells keep our heads from coming open, but they also deter us from riding bicycles. And riding bicycles is good for people and Earth.

Admonishing a teenager for smoking is commonplace. Reprimanding people for taking antibiotics when they don’t really need them is the next big thing. And giving people a hard time about biking without a helmet is still entirely in vogue. It’s because we care. But as we learned from the original food pyramid, sometimes good intentions pave the road to adult-onset diabetes. Read more