He is smart, mate. He's a psychopath. And I mean that genuinely. A lot of high achieving people have mental disorders and I'm pretty convinced that Barton is a psychopath.
Most psychopath's are articulate, charming and manipulative and are experts at mimicking normal human behaviour.
Edit: That's not my diagnosis by the way. A friend of mine, who works as a psychiatiric nurse pointed it out. I happen to think it ring's true.
