It is called ‘passive tolerance’ and it is the most hopeful piece of social theory to emerge in a long time.

It is the notion that living in an area of high diversity can make you more tolerant and accepting of ethnic differences.

The theory has emerged from seven studies carried out over a decade in Europe, the US and South Africa led by a team from Oxford University.

Two of the studies were conducted over several years and tracked the same individuals, showing how attitudes changed. Even prejudiced people showed a greater degree of tolerance over time if they lived in a mixed neighbourhood.

Published in the journal of the United States National Academy of Science, the first two studies show that interactions between different ethnic groups on an average street: the newsagent, the local shop, the delivery driver, the postman, friends laughing, children playing, a pair of lovers is what generates passive tolerance.

You don’t have to be part of the interaction yourself; just witnessing it is enough to have a significant impact, the researchers say.

This positive message is reinforced by the finding of a separate study by the same Oxford team – the largest to date in the UK on diversity.

White British people were asked whether they felt ethnic minorities threatened their way of life, increased crime levels, or took their jobs; ethnic minority participants were asked the same questions.

Both groups were then asked about how they interact with other groups in everyday situations, such as local shops, and then about how much they trusted people from their own and other ethnic groups in their neighbourhood.

What the study found was that distrust does rise in diverse communities, but day to day, direct contact cancels it out.

The two studies together point to a more optimistic reading of how diversity impacts on urban communities.

The researchers were careful to rule out the most obvious explanation for their finding – for instance – that the higher levels of tolerance in more diverse communities were a result of more tolerant people choosing to live there. The studies tracked the same individuals over several years.

The research also helps build the case for local initiatives to foster social exchange and build community relationships.

From festivals to coffee mornings, garage sales to fun days in the park – all these are opportunities to generate passive tolerance.

To see the full study, go to: http://www.ox.ac.uk/media/news_stories/2014/140304.html