Anecdotally, I am one of those people who interject when people are talking to me. I know it's a bad habit, but in most cases I DO think faster than almost everyone I meet, and from my perception people take forever to explain their point. Most of the time I know exactly where they are going on the topic, and I bore easily, so find myself interrupting. It is one of my worst traits, but I challenge that it's because I don't think. I think deeply about everything and anything as I have a constant desire to learn regardless of topic. The down side of this is that most people talk absolute rubbish about topics they know nothing about, yet seem to enjoy doing it, and resent being corrected or educated. I had to learn this the hard way. These days I just don't engage in any general conversations with colleagues or acquaintances for this very reason.