Worries about social cohesion are on the rise. Initiative Chair Roger Partridge aired his concerns in the Herald last month, and this month saw the launch of a report on the subject by the Helen Clark Foundation.  

One aspect of social cohesion is cooperation. Studies have repeatedly shown that ethnically diverse societies are worse at some types of cooperation, especially when it comes to providing public goods. 

A public good is one that everyone can enjoy even if they haven’t helped provide it. Security is a common example. As long as there are enough soldiers to defend the borders, I don’t have to lift a finger to enjoy the security they’ve provided.  

People who enjoy a public good without contributing are called ‘free-riders.’ One way that societies can discourage free-riders is through social sanctioning: giving free-riders a bad reputation, withdrawing personal favours, and so on. 

Research by the Georgetown economist James Habyarimana has suggested that these dynamics can help explain why diverse societies can struggle to provide public goods. During his fieldwork in Uganda, Habyarimana found that people tended to socialise with those of the same ethnicity. That meant it was easy for them to apply social sanctions to co-ethnics, but not to individuals of other ethnicities. 

That, in turn, meant that cooperating with people of other ethnicities offered free-riders an opportunity. If they were collaborating with co-ethnics, free-riders would fear incurring social sanctions from friends and family. If they were working with people of other ethnicities, though, they had less reason to care, since those people were unlikely to be part of their social world. 

Habyarimana’s research not only identifies why social cohesion can be lower in diverse societies, but also suggests how it might be enhanced. If social networks are what’s crucial for cooperation, all we have to do is make sure that our social networks cross racial boundaries. 

That, of course, is easier said than done. The Helen Clark Foundation report found that only 64% of New Zealanders (compared to 81% of Australians) saw their local area as ‘a place where people from different national or ethnic backgrounds get on well together.’ 

​On the other hand, the Initiative’s 2017 report The New New Zealanders found that we have relatively little residential clustering by ethnicity. That might make it easier for us to take some easy steps towards greater social cohesion by simply connecting more with neighbours – especially those that look or talk differently.