White Americans who had more black contemporaries when they were at school are more likely to date and marry black people as adults. That is the central finding of research by Luca Merlino, Max Steinhardt and Liam Wren-Lewis, to be presented at the Royal Economic Society''s annual conference at the University of Sussex in Brighton in March 2018.

The study compares students within the same school, contrasting those who happen to be part of cohorts with fewer black people to those in cohorts with more black people.

It''s not that these students date more black people in school – the number of students of the opposite gender does not have any impact. Instead, students in cohorts with more black people end up having more social interactions with blacks and are more likely to make black friends.

The researchers note that interracial marriage is still surprisingly rare, with previous research suggesting that adults prefer to date people of their own race. That prompted them to ask where such preferences come from.

Their finding that an important factor is who people went to school with suggests that interactions at school lead to students who as adults are less likely to think that race is an important factor within a relationship.

Moreover, cohort composition affects relationships formed many years after school, implying the increase in mixed-race relationships is not simply driven by students meeting more black partners in school or via school friends.

Overall, therefore, the results suggest that racial diversity in schools can help lead to positive changes in attitudes and behaviour towards those of other races.

Luca Merlino (University of Antwerp), Max Steinhardt (Helmut Schmidt University) and Liam Wren-Lewis (Paris School of Economics)