I didn't say "only".
Either way, I don't buy it. I'm sure you can find exceptions, but from what I've seen from people both in real life and on this forum, I have every reason to be cynical about what criteria people use for determining "respect". In my experience, people respect people almost arbitrarily, and then rationalise it after they've decided that they respect them. Can't prove it, but hey, it's one of those things that isn't going to be argued conclusively either way
The poll asked for the primary criterion for respect. We're talking about intelligence. The implicit assumption, when I say respect, therefore, is that I am talking about respect for people's "intelligence", or at least what people claim to be respect for intelligence.