10 Ways We Get the Odds Wrong

Is your gym locker room crawling with drug-resistant bacteria? Is the guy with the bulging backpack a suicide bomber? And what about that innocent-looking arugula: Will pesticide residue cause cancer, or do the leaves themselves harbor E. coli? But wait! Not eating enough vegetables is also potentially deadly.

These days, it seems like everything is risky, and worry itself is bad for your health. The more we learn, the less we seem to know—and if anything makes us anxious, it’s uncertainty. At the same time, we’re living longer, healthier lives. So why does it feel like even the lettuce is out to get us?

The human brain is exquisitely adapted to respond to risk—uncertainty about the outcome of actions. Faced with a precipice or a predator, the brain is biased to make certain decisions. Our biases reflect the choices that kept our ancestors alive. But we have yet to evolve similarly effective responses to statistics, media coverage, and fear-mongering politicians. For most of human existence, 24-hour news channels didn’t exist, so we don’t have cognitive shortcuts to deal with novel uncertainties.

Still, uncertainty unbalances us, pitching us into anxiety and producing an array of cognitive distortions. Even minor dilemmas like deciding whether to get a cell phone (brain cancer vs. dying on the road because you can’t call for help?) can be intolerable for some people. And though emotions are themselves critical to making rational decisions, they were designed for a world in which dangers took the form of predators, not pollutants. Our emotions push us to make snap judgments that once were sensible—but may not be anymore.

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