The authors insist that the more unequal a society is, the higher its risk of becoming dysfunctional. Countries tend to do either well or poorly on all different outcomes, from health to education. The most consistently high-ranking countries are Japan and Scandinavian nations, while the most consistently poor performers are the US, the UK, and Portugal. The authors present a graph that combines all of the results they reference in their work as a visual summary of their overall findings.

Wilkinson and Pickett argue that reducing inequality will not only help society’s poorest but people across all social classes because inequality creates social problems that are not limited to the poor. The authors cite a study that compares middle-aged white people in the US and England and found that the Americans consistently had poorer health than their English counterparts. They reference other studies on mortality in different countries to demonstrate that equal countries have lower mortality rates across social classes than more unequal ones. Researchers had similar findings when comparing individual US states: the more equal states had lower death rates across all social classes. Comparing educational scores revealed similar results; even the best-educated kids in the US and UK did not do as well as the highest-educated kids in Finland.