But you have to adjust for the fact that on many issues people don’t actually apply their full attention and come up with independent conclusions.
It's not just that they didn't give it their full attention, but that part of their attention is focused on correlations with the opinions of others.
An interesting blog post by Razib Khan, who many here probably know from his Gene Expression blog, the old gnxp site or perhaps from his BHTV debate with Eliezer.
I recommend following the link and reading the rest of it there, not only does interestingness continue, the comment section there is usually worth reading since he vigorously moderates it.