If trust is the social glue that makes for a more cooperative and better functioning society, raising the level of trust should be a priority for each nation. Yet, it is not easy to convince us that others are part of our “moral community,” especially when there are high levels of segregation and inequality. People of different backgrounds may not be ready to place their faith in each other. As societies become more diverse, finding commonalities becomes ever more important.

Contact with people of different backgrounds does lead to a reduction in racial prejudice (Pettigrew and Tropp, 2011). By itself, it does not lead to more trust. To get to trust, you need more than simple contact. Allport’s “optimal conditions” demand more: a context favoring the development of deeper contacts (integrated neighborhoods) and equality (contacts between equals).

I review the i ndings of previous chapters and return to where I started: How does one build trust, especially as societies have become more diverse and especially as their publics increasingly come from countries with low levels of trust? Optimal contact may not do the job, largely because the majority’s friendship networks are not sufficiently diverse – and especially because it is difi cult to establish such ties when the social milieus are unequal. Whites across every society are far less likely to have friends of different backgrounds. We seek out people like ourselves as our friends – and at least in the United States and the United Kingdom we prefer to live among people who look like ourselves. Even when segregation is low, minorities tend to live away from the majority population. The economic distance between majorities and minorities is often large, and even when it is not, feelings of discrimination may lead to a great social gap. After summarizing the evidence from previous chapters, I reconsider what might be done to build trust among people of different groups.