“I’ve done it since I was a kid.” “I guess I’m just not going to change.” If there’s one thing we know about habits—our routine patterns of behavior—it’s that they’re tough to break. That’s because whether they’re helpful (brushing our teeth every night before bed) or potentially harmful (biting our nails), they become hardwired into our brains. “Something acts as a trigger, you react with a certain behavior, you get a reward, and you repeat it,” says Judson Brewer, a neuroscientist at the University of Massachusetts. All habits, good or bad, follow this loop. And the stronger the loop is, the harder it is to break.