Here are two tidbits from this excellent essay: 

1. I submit that the unifying core, the essence of jerkitude in the moral sense, is this: the jerk culpably fails to appreciate the perspectives of others around him, treating them as tools to be manipulated or idiots to be dealt with rather than as moral and epistemic peers.

2. To discover one’s degree of jerkitude, the best approach might be neither (first-person) direct reflection upon yourself nor (second-person) conversation with intimate critics, but rather something more third-person: looking in general at other people. Everywhere you turn, are you surrounded by fools, by boring nonentities, by faceless masses and foes and suckers and, indeed, jerks? Are you the only competent, reasonable person to be found?