Our world is shaped by widespread statistical illiteracy. We fear things that probably won’t kill us (terrorist attacks) and ignore things that probably will (texting while driving). We buy lottery tickets. We fall prey to misleading gut instincts, which lead to biases like loss aversion—an inability to gauge risk against potential gain. The effects play out in the grocery store, the office, and the voting booth (not to mention the bedroom: People who are more risk-averse are less successful in love).