Why are we devastated by a word of criticism even when it’s mixed with lavish praise? Because our brains are wired to focus on the bad. This negativity effect explains things great and small: why countries blunder into disastrous wars, why couples divorce, why people flub job interviews, how schools fail students, why football coaches stupidly punt on fourth down. All day long, the power of bad governs people’s moods, drives marketing campaigns, and dominates news and politics.

Eminent social scientist Roy F. Baumeister stumbled unexpectedly upon this fundamental aspect of human nature. To find out why financial losses mattered more to people than financial gains, Baumeister looked for situations in which good events made a bigger impact than bad ones. But his team couldn’t find any. Their research showed that bad is relentlessly stronger than good, and their paper has become one of the most-cited in the scientific literature.