Frank Murtha is a psychologist with MarketPsych who specializes in investor behavior. Or misbehavior. Or misconceptions. Well, all of that. His job is to study how people make decisions with their money, and to help us understand (and avoid) common mistakes.

He stopped by to talk to us about how a crashing stock market changes the way investors invest. (Hello, recession of 2008!) Pretty interesting stuff. Check it out: