2016 has been seen by many as a watershed political year: The rise of populism, the decline of the elites, and the birth of so-called ‘post-truth’ politics. First came Brexit, then the rise of Donald Trump. Commentators should be wary of linking the two results too closely. Leaving the European Union was a position supported by many sensible members of both the Conservative Party and Labour Party, while, by election day in the United States, there were almost no MPs in Westminster willing to publicly endorse Trump. However, the two elections did share one common feature: a sharp focus on immigration control.

In the UK, voters told Ipsos-Mori that immigration was the most important issue during the referendum, even more important than the economy. For Leave voters, it was particularly crucial, with over half reporting it to be one of the most important issues, compared to 33% of all voters. The official Leave campaign was not shy of focussing on the issue: It claimed that a vote to Remain was a vote for "uncontrolled immigration". In the US, 70% of voters cited immigration as “very important to their vote”, while 79% of Trump supporters said the same. The Trump campaign was even more bullish in its use of immigration. Trump rallies became noted for their chants of “build the wall” while the Republican nominee promised to ban all Muslims from entering the US.

Some have argued that this anti-immigration rhetoric and its apparent resonance with voters was driven by economic concerns. They contend that increases in immigration reduce the employment level of the native population and reduce wages. Yet, there is scant evidence for this. In a telling section of an account by Daniel Korski, a former adviser to David Cameron, he recounts the negotiations which took place with EU leaders prior to the referendum. Korski reveals that Number 10 attempted to convince them that the UK required immigration controls due to the economic costs of immigration. In response, the EU leaders contended that the UK economy was growing, the UK was almost at full employment and that European migrants paid more tax and used fewer public services than British citizens.

Number 10 tried to find convincing evidence to counter this, but were unable to. It was true.

So, if this anti-immigration rhetoric is not being driven by economic concerns, then what is driving it? Some have attributed it simply to racism. It is certainly possible that this was the motivation of some Leave voters and some Trump voters. Yet, to attribute the campaigns’ victories to racism seems pessimistic. It requires us to believe that huge numbers of American and British voters are either racists or too ignorant to identify racism.

Others have attributed the growth in anti-immigration rhetoric to cultural concerns. One of the most pressing cultural concerns is the issue of integration in our communities. There is a significant body of evidence which suggests that immigration may have some negative effects on community integration. The American Professor Robert Putnam has found that in communities with the most diverse population, neighbours trust each other around half as much as they do in communities with the most homogenous population. Neighbourhood trust is viewed by many social scientists as a reliable indicator of integration.

There is some evidence that lower levels of trust may have had an impact on the decision of the British people to leave the EU. The British Election Survey asked UK voters whether most people in their community can be trusted, or whether you can’t be too careful. It found a clear division between those who said that most people can be trusted, amongst whom 40% voted Leave, and those who said you can’t be too careful, 64% of whom voted Leave.

In the weeks following Trump’s election victory, evidence is yet to emerge of the relationship between neighbourhood trust and Trump’s victory. Yet evidence from Trump’s primary victory, when he claimed the Republican nomination for the Presidential election, shows that he was more likely to win in states with low levels of social connectedness.

Commentators should always be wary of attributing any complex electoral phenomenon to one factor. Yet it seems possible, even probable, that low levels of neighbourhood integration played a role in both Brexit and Trump. For any ideology to succeed, it must be prepared to admit its weaknesses. Over the last three decades, the West has enjoyed an unparalleled growth in wealth but it may have come at some costs. We must be conscious of the importance of our communities and do all we can to ensure they thrive.

James Dobson is a researcher at Bright Blue. This is an article from Bright Blue’s magazine The End of the Establishment?