First, it suggests that Machiavelli had it wrong and that nice guys actually do finish first, in the sense that those who backstab and play politics tend to become isolated and ostracized fairly quickly in groups. Huzzah. Good news, right?
Second, those who do rise to power become less like themselves and tend to become less sensitive and responsive to others, becoming more and more sure of themselves and their own opinions.
Most people who become boss-types don't want to become insensitive asses. (Even these people didn't intend to be bad.) But the research suggests that this trend is a function of becoming isolated from day-to-day activities, which any senior manager has to be in order to allow their team to work. Distance is not good, but it is necessary.
Which is a pretty damn delicate thing to be balanced, one that gets increasingly difficult the higher up you go.
Just be careful about putting those feet on the desk, and who you point them at.