This is a relatively long post addressing an issue of great importance in this year in America: the contribution of immigration to social tensions. Is there a relationship? If so, what are the mechanisms? I summarize the case for a relationship and then suggest three somewhat overlapping mechanisms.
In the past 20 years, many researchers have looked at the impact of diversity on the level of social trust in a society. Much of that research focuses on ethnic/racial diversity, as opposed for example on religious and social class diversity. A recent review of 87 research articles found a statistically significant negative relationship betweem ethnic diversity, for example due to immigration, and social trust including social trust within groups.
The Center for Immigration Studies uses this review as evidence of ill effects of immigration.
A seminal study was done in around 2000 by one of America’s most respected social scientists, Robert Putnam. Fighting his personal pro-immigrant leanings, he warned, “The more ethnically diverse a residential context is, the less we trust …” He said the more racially diverse a community, the less trust exists among neighbors. Even trust within groups is lower in more diverse settings.
In thinking about these disturbing findings, it is useful to take several things into account:
First, the studies do not (as far as I can see) address other types of diversity – economic class, social class, religion. Would the emergence of an evangelical community within a traditional Christian domination community also affect social trust? Is increase in diversity related to, say, economic upheavals that erode trust?
Second, these studies do not deeply explore the mechanisms by which diversity reduces social trust within groups. There appears to be little attention given to psychology. I can think of three kinds of mechanisms.
One is the degree to which people sense that they can enjoy reciprocity with one another across ethnic boundaries. Diversity may erode one’s confidence in reciprocity in all instances.
Pre-existing low trust in public institutions may hasten the decline in trust. There appears to be a positive correlation between social trust and a society one the one hand, and trust in government, law and the police on the other hand. Pre-existing low trust in these institutions might aggravate a decline in social trust due to ethnic diversity.
A third possible mechanism is group politics. A culture of leadership may emphasize zero-sum game relations with out-groups, made up threats from outside, preach dependence on the leader to ward off threats, and enforce conformity, and undermine norms of government, law and policing. This might, in the face of diversity, increase psychological distress within the group. I have in mind Donald Trump.