A nice article by Virginia Postrel in the Atlantic, writing about the behavioral economics of asset bubbles. Pop Psychology .
In short people are irrational, and one might add backward rather than forward looking.
I think the backward looking nature of humans also explains infrastructure bubbles, growth is extrapolated from past trends, and as we rise the logistic curve past the midpoint, this overstates future growth. See The Transportation Experience for details.
The text can be found on p.253, see the Google Books version for discussion.