I am going to cut and paste this blog in its entirety - because I couldn't have written it any better. All I can say is "This explains a lot!".
Posted by: Jena McGregor on May 20
You may think it’s your boss who’s always the one messing things up. But according to new research in the journal Pyschological Science, people with lower-ranking titles are more likely to make errors than those with higher-ranking roles. That’s because, says Adam Galinsky, a study co-author and professor at Northwestern’s Kellogg School of Management, the “executive functions” of the brain, or the gray-matter processes that override automatic responses, can be impaired when people are put in jobs with little power. In Galinsky’s study, which was co-authored by Pamela K. Smith, Nils B. Jostmann, and Wilco W. van Dijk, subjects who were randomly assigned to be subordinates had a harder time staying focused on goals than those who, by chance, were named to be managers.
The research isn’t the first Galinsky has done on the effects of power on performance. In another study, he had students sit down very close to electric fans blowing in their faces. Sixty-nine percent of those randomly assigned to be managers moved the fans, while just 42% of those named subordinates did. Galinsky believes such research helps confirm why employee “empowerment”—especially in health care, or high-risk factory jobs—should be much more than just lip service. Says Galinksy: “Lacking power impairs those parts of the brain that allow people to stay focused.”
I wouldn't really call it "power" though - it's "control" or the perception of the ability to make a difference and to control one's environment. Once that is lost - all is gone.