Peak Oil is a large and scary concept to get one's mind around. If there are arguments around the water cooler about finite resources, large depletion rates, Peak everything, etc., there are probably cognitive biases underlying these polarized opinions. In the first two parts of this series, we looked at some of the factual reasons why people disagree on the timing and importance of Peak Oil: gross versus net oil production, better technology vs depletion, productive capacity vs flow rates, differing definitions of "Peak", etc. This post will address some social and psychological reasons why the urgency of our energy situation may not be being addressed on an individual level and only at a snails pace on the governmental level. Among the phenomena we will explore are a) why we have beliefs and how they are changed, b) our propensity to believe in authority figures, c) our penchant for optimism, d) cognitive load theory, e) relative fitness, f) the recency effect, and several others. The fact is, even if the world's energy data was transparent and freely available to everyone, it would be an open question whether people would agree on any near term action to mitigate future oil scarcity. This post is a first stab at examining our cognitive belief biases. It's long, but I believe it will be well worth your time to read. (Note - This is an updated version of a post that first ran in May.)