Well, some of them can be pretty obnoxious but I have always attributed that to the fact that they were from New York City. :-)
The only really obnoxious, but very smart, one I ever knew was indeed from New York City. He was a walking talking stereotype. His name was even Stanley, like the doorman in Crocidile Dundee.
Some of the co-crazies of Mr. Irving beat the snot out of him one day, came really close to killing him in fact. He wasn't *that* obnoxious, especially for a PhD physicist. Fortunately his company took good care of him, even flying his mother in to Dallas from New York City.