Jonah Lehrer describes the neurological mechanism:
Once we become socially isolated, we stop simulating the feelings of other people.* As a result, our inner Machiavelli takes over, and our sense of sympathy is squashed by selfishness. The UC Berkeley psychologist Dacher Keltner has found that, in many social situations, people with power act just like patients with severe brain damage. "The experience of power might be thought of as having someone open up your skull and take out that part of your brain so critical to empathy and socially-appropriate behavior," he writes. "You become very impulsive and insensitive, which is a bad combination."
Of course, we live in an age when our most powerful people - they tend to also have lots of money - are also the most isolated. They live in gated communities with private drivers. They eat at different restaurants and stay at different resorts. They wear different clothes and skip the security lines at airports, before sitting at the front of the plane. We shouldn't be surprised that they're also assholes.
*I think this helps explain the public preference for politicians with ordinary preferences, or why Scott Brown kept on talking about his truck. And it also justifies Obama insistence on not becoming informationally isolated, whether that's by reading ten letters from constituents every day or following a variety of blogs.
(Photo: Mandel Ngan/AFP/Getty.)