I guess we'll just have to agree to disagree about most people thinking critically. I don't have anything other than personal experience to justify my position and a quick Google search wasn't able to turn up any convincing studies.

Group cognition (from a quick skim of a Wikipedia article about it) doesn't seem to justify lack of individual critical thinking though. It seems to be more like a term to describe a process, like "memes" and "idea viruses". It doesn't substitute for individual critical thinking.