"The brain works more like a muscle than we thought," Blake says. "So if you're pinned in a corner for too long listening to someone being negative, you're more likely to behave that way as well."
Even worse, being exposed to too much complaining can actually make you dumb. Research shows that exposure to 30 minutes or more of negativity--including viewing such material on TV--actually peels away neurons in the brain's hippocampus. "That's the part of your brain you need for problem solving," he says. "Basically, it turns your brain to mush."
