Both Bar-Yam’s and Cederman’s research suggests one answer to diversity within nation states: devolve power to local communities, as multicultural states such as Belgium and Canada have done.

“We need a conception of the state as a place where multiple affiliations and languages and religions may be safe and flourish,” says Slattery. “That is the ideal Tanzania has embraced and it seems to be working reasonably well.” Tanzania has more than 120 ethnic groups and about 100 languages.

Debora MacKenzie at The New Scientist. End of nations: Is there an alternative to countries? Nation states cause some of our biggest problems, from civil war to climate inaction. Science suggests there are better ways to run a planet (via protoslacker)