Yeah, I'd be curious to dig into the specifics of that research a little more. My gut is telling me that there may be other factors at play that could explain t

Yeah, I'd be curious to dig into the specifics of that research a little more. My gut is telling me that there may be other factors at play that could explain this sort of thing. People who respond quickly are likely also showing signs of eagerness -- nodding your head, smiling, saying "yeah" or "oh wow!", in ways that may communicate enthusiasm for the subject (even if it's really just eagerness to jump in and say what they want to say). Sitting back and listening carefully may also be accompanied by body language suggesting being withdrawn or uninterested in engaging further -- even if they are, indeed, quite interested. I'm just speculating at this point, and certainly I'm only talking about broad, generalized patterns. But I would expect body language is an important factor to account for in this sort of research.