Social scientist Robert Putnam discovered this in hard data, although he didn't write up the results until 5 years after publishing the data: https://en.wikiped

Social scientist Robert Putnam discovered this in hard data, although he didn't write up the results until 5 years after publishing the data: https://en.wikipedia.org/wiki/Robert_D._Putnam#Diversity_and_trust_within_communities https://en.wikipedia.org/wiki/Robert_D._Putnam#Diversity_and...