Evidence has accumulated showing that, in the richer countries or states, a greater level of economic inequality is associated with a higher prevalence of a wide range of health, social, and educational problems for adults and children, the same problems which display strong social class gradients within the population. The leading theory for explaining these harmful effects is social evaluative threat theory: inequality fosters social evaluation anxieties and the making of upward social comparisons, increased feelings of social identity threat, shame, and inferiority, and reduced trust in others. A rich combination of survey, experimental, and other research methods has been used to test variants of the theory. Among the profound effects of economic inequality, for which supportive evidence has been found, are: pressured decision-making, risk-taking, narcissism, self-enhancement, and competitiveness. Although larger differences in incomes and in wealth are bad for collective health and well-being, there may be contradictory effects for individual people, depending on their economic circumstances and how they have reacted to inequality. We are divided in our reactions to inequality. To obfuscation and diversion, identified in earlier chapters as sources of confusion about economic inequality, we can now add a third source, division.