In my experience, you're not talking about the ones who are significantly smarter, just the ones who think they are. They intimidate coworkers not because they're smarter, but because they're obnoxious egomaniacs who never stop talking long enough to listen to people who are trying to communicate to them how very wrong they are.
I don't think it's so black and white.
Very smart people intimidate or otherwise engender negative reactions in people who aren't as smart without even being aware of it. Using "big words," long or complex sentences, and showing signs of nuanced thinking can all be interpreted as being an obnoxious egomaniac who's out to prove you're better than everyone else. So can arguing passionately about something.
The smart person may have
no idea that s/he's using "big words" because they're just everyday words to the speaker. And likewise, no clue that making a point based on evidence or logic may not be appreciated by others who have trouble following the logic.
