Most of us prefer to hang around with people who are much like ourselves. We like neighbourhoods full of people who are similar to ourselves, we get intimate with people like us, and we join clubs and interest groups of like-minded people. It also happens that we inevitably end up spending most time with people not just with shared interests, but also of similar ethnicities, faiths, socio-economic background, cultural assumptions, and life experiences.
This ‘principle of homophily’ is well known in the social capital literature, and it can indeed help make life easier and more pleasurable much of the time. But according to Johnson, it also makes our decision-making capacities more vulnerable. He believes that the greater the diversity of those involved, the better our decisions. This is because people with varying backgrounds and assumptions will challenge and question each other, rather than simply going with the flow.
So a wider range of participants from different backgrounds is not just a matter of fairness; it also leads us to make better decisions. This is consistent with social capital research which shows a number of advantages to heterogeneous networks: as in the well-known case of job opportunities, to take one example, they are better than tight networks of folk like us for exposing us to information and ideas that we might otherwise miss /or overlook.
I agree with most but not all of Johnson’s analysis of networks and decision-making. First, for some purposes it is best to have access to a tight networks of people like us. To give one example, if you need a loan to start your new business, family and close friends are more likely to help than people you don’t know so well. More controversially, some research shows that pupils perform better academically when taught by members of the same ethnic group or gender.
So we appear to need a balance of heterogeneity and homogeneity to provide a mix of different resources to see us through our lives. Mixing only with people like yourself is a sure fire way of limiting your options; mixing only with loose ties is to cut yourself off from dependable and secure relationships.
Second, Johnson doesn’t discuss the policy implications of his thinking (though he does have interesting things to say about fiction and decision-making). He doesn’t look at organised attempts to bring large numbers of different people together to deliberate on agreed solutions to shared problems, such as citizens’ juries or other moderated large scale debates.
When they work, as in some types of community planning, they are great; when they become shouty (eg the two sides of Brexit) they just make matters worse. In short, how can we best improve public decision-making capacity through organised diversity?