Even the smallest dose of power can change a person. You've probably seen it. Someone gets a promotion or a bit of fame and then, suddenly, they're a little less friendly to the people beneath them.
So here's a question that may seem too simple: Why?
If you ask a psychologist, he or she may tell you that the powerful are simply too busy. They don't have the time to fully attend to their less powerful counterparts.
But if you ask Sukhvinder Obhi, a neuroscientist at Wilfrid Laurier University in Ontario, Canada, he might give you another explanation: Power fundamentally changes how the brain operates.
"What we're finding is power diminishes all varieties of empathy," says Dacher Keltner, a social psychologist at University of California, Berkeley, not involved in the new study. He says these results fit a trend within psychological research.