Shy people are more sensitive to reward than outgoing people

A study published in the new issue of the Journal of Neuroscience (link via Science) found that shy individuals show more activity in the reward-associated area of the brain (i.e., the striatum) than outgoing individuals. Interestingly, no differences in amygdala activity was found between the two groups. I suspect that is due to the fact that the risk-taking task was not salient to the types of things that shy people fear. If anyone has evidence to the contrary I would be interested in reading about it.