Jonah Lehrer on Loss Aversion 

The amygdala, the part of the brain believed to be responsible for fear, is likely also related to the human aversion to loss. Researchers at UCL and Caltech have found evidence that people with damaged amygdalas are willing to make riskier decisions:

Both amygdala-lesioned participants showed a dramatic absence of loss aversion yet they retained a normal response to reward magnitude. This pattern of behavior is consistent with evidence that monkeys with amygdala lesions maintain a stable pattern of preference among sets of food items even though they will approach foods that are paired with potentially threatening stimuli more quickly than control monkeys.