Agreed. But, for those who might be looking to this thread for advice on how to detect assholes as early as possible, know the difference between prudence and cynicism. Be cautious, but don't start out assuming that someone's good impression is just a facade, otherwise the entire rest of that relationship will be tainted by that.

It also doesn't hurt to go back later and try to understand why you had the gut feeling that the person is an asshole. Knowing what sort of cognitive biases you may have, either from instinct or socialization, will likely help the false positive rate. And the more you are considerate about things, the less you might be likely to come off as a prejudicial asshole to someone else.

Definitely. My girlfriend made the comment to me a couple of days ago, that she overwhelmingly finds people she initially judges as mean or rude often turn out to be lovely people, and those she initially judges as nice people often turn out to be heavily flawed.

Personally, my snap judgements seem to be pretty reliable. Many times I've taken an instant disliking to someone, while other in the social group found the opposite, when months or years later the person will confirm my suspicions by involving themselves in some big scandal or something.

I think knowing when and when not to trust your intuition is a big part of the intuitive process.