You're on to something with 'lack of information'. I'm not perfect in this (when I first started commenting on HN, an alarming proportion of replies said that I had confirmation bias or 'correlation is not causation'), but I've learned to find data and (most importantly) evidence to support alternate conclusions. It's not obvious until something doesn't have the intended results, but by the time I've investigated and figured out why, I'm too thrilled to see it work out that I don't check to see whether the initial choice had confirmation bias.
