It is worth noting that Daniel Kahneman and Amos Tversky are the fathers of modern-day behavioral economics. Their biggest contribution is called Prospect Theory. It goes against everything they teach you in Econ 101 -- the expected utility theory is wrong.
Kahneman won a noble prize in Economics for his work. Sadly, Tversky passed away in 1996 before he could be awarded.
Prospect Theory: http://en.wikipedia.org/wiki/Prospect_theory