Leaders who aim to boost organizational performance often start with efforts to kindle good behavior, however they define it. Yet case studies and rigorous academic research show that if you want to create and spread excellence, eliminating the negative is the first order of business. Destructive behavior—selfishness, nastiness, fear, laziness, dishonesty—packs a far bigger wallop than constructive behavior. Organizational researcher Andrew Miner and colleagues, for example, measured the moods of 41 employees at random intervals throughout the workday. The researchers discovered that negative interactions with bosses and coworkers had five times more impact on employees’ moods than positive interactions. This “bad is stronger than good” effect holds in nearly every other setting studied, from romantic relationships to group effectiveness.