TED演講:經(jīng)濟(jì)不平等如何危害社會(huì)（5/5）

Interestingly, some parallel work going on in social psychology: some people reviewed 208 different studies in which volunteers had been invited into a psychological laboratory and had their stress hormones, their responses to doing stressful tasks, measured. And in the review, what they were interested in seeing is what kind of stresses most reliably raise levels of cortisol, the central stress hormone. And the conclusion was it was tasks that included social-evaluative threat -- threats to self-esteem or social status in which others can negatively judge your performance. Those kind of stresses have a very particular effect on the physiology of stress. Now we have been criticized. Of course, there are people who dislike this stuff and people who find it very surprising. I should tell you though that when people criticize us for picking and choosing data, we never pick and choose data. We have an absolute rule that if our data source has data for one of the countries we're looking at, it goes into the analysis. Our data source decides whether it's reliable data, we don't. Otherwise that would introduce bias.