impact of psychology on finance and traders

For all their flair and boasted smugness, traders are not nearly as rational as they claim to be. This principle, which is in open conflict with the conventional Efficient Market Hypothesis supported by Modern Finance, is at the heart of a new discipline called behavioral finance. These studies target the cross-territory between psychology and finance and have an impressive body of empirical evidence supporting their statements.
What are the most common human frailties preventing the rational decision-making postulated by...