Across the globe, most people in these small scale societies offered some amount of the initial pot. Across the globe, most people rejected really low offers. This shows the universal signature of fairness: an expectation of sharing resources and a no-tolerance view of greed. Cultures differed with respect to how much they shared and whether they rejected. Some societies offered, on average, close to 40%, while others offered as little as 15%. Some societies accepted virtually all offers, whereas others rejected both low and even high offers. Even in more egalitarian societies, therefore, there is sensitivity to unequal distributions. Even in egalitarian societies, there is a willingness to punish those who act unfairly, greedily taking more than their fair share. The work I have discussed on fairness is only a fraction of the growing body of scientific evidence. What this research reveals is that a sense of fairness is part of human nature, appearing early in development, but guided by experience toward a particular cultural form. When our desire for fairness or equity combines with our competitive drive, envy often follows. Studies of the brain show how envy is generated from this combination. When healthy subjects sit in a brain scanner and learn about other individuals who have what they desire, there is considerable activity in the anterior cingulate, and more activity in those who feel more envious. This is not the envy center of the brain. There is no such area. But the recruitment of the anterior cingulate in other social situations helps us understand what is going on more generally in the case of envy. The anterior cingulate activates when we experience pain from social exclusion, but not when we witness such pain in others. It is one of the areas that was activated in Chiao’s work on the differences in pain empathy for those supporting either an egalitarian or hierarchical society. The anterior cingulate is also involved when our minds are pulled in two