Another study in neuroeconomics -- using brain scans to investigate how people make decisions -- has revealed that some people react to the anticipation of pain as if it was the pain itself. These people would sooner have a stronger shock immediately than wait a while for a milder shock -- a choice that is more understandable now we've seen that there is increased brain activity in the area of the brain that perceives pain. (yahoo report; Nature report)

And a study of capuchin monkeys has revealed that they are as loss-averse as humans, suggesting that this attribute of ours is innate, not learned.