2. Intelligent Women
If you're super smart, he's going to have trouble finding something to talk to you about. He won't want to bring up a topic that he's clueless about, because he won't want you to think that he's dumb. Of course, he won't want to bring up something mindless either, because he'll assume that it's too dull for you to talk about. That's why he might psych himself out and avoid talking to you entirely.