I have thought for a while that the rational actor that is central to many economic theories might be an outgrowth of the psychological model of the individual mind. Adam Curtis of the BBC has a wonderful documentary post about the role of the rational actor model in the development of theories of counterinsurgency, from the Algerian civil war, through Vietnam, to Iraq and Afghanistan. In each case, the attribution of domains of significance to the individual only, and an impoverished individual at that, led to a complete failure to comprehend the webs of social meaning which were the fabric of people’s lives.
The documentary blog entry is here. How to Kill a Rational Peasant.