Janice Janes had a very informal, very anecdotal hypothesis: before the human condition first acquired consciousnes, our existence was dictated by a non self-aware construct he termed the bicameral mind. Janes argues that the development of consciousness is in part language based, and in part wired into our brains, based upon the authority structures of the culture. Consciousness thus developed over time as the challenges of dealing with multiple interacting cultures forced the simple structures to break down and be reconstituted, generation after generation.
I don't know whether Janes' ideas were away in left field or in any way mainstream, but they were intriguing. Through his lens it was easy to interpret xenophobia, black and white doctrines, separatism, etc. as attempts by a subculture to regain some measure of the simplicity of the less self-reflective mind.
Janes' assumptions that consciousness was/is an ever progressing evolutionary eventuality are wrong. Cultures can and do move backwards towards a less than fully conscious hive mind mentality. If anything, consciousness is Lamarkian, not Darwinian. Consider the culture of Afghanistan, or, closer to home, religious cults. Fanatical followers of media personalities such as Oprah or Jim Bakker (not to say they are equivalent however) oven have great difficulty separating their own opinons from those espoused by their glorified leaders. Prejudice is the antithesis of consciousness.
And it isn't just about collectivist authority structures, but personal identity. Experience of the world drives consciousness about that world. Less experience implies a narrow, specialized focus but also a limit to consciousness. Ignorance is bliss. Experiences by proxy, as through the Web and TV, create a consciousness that does not accurately image or respond to the physical and social world. In this case, ignorance is not bliss as the conflicting and falsified viewpoints creates unnecessary and unhelpful reflection.