It would be interesting to see the results of a large study where people are asked questions like:
"Lopax was born in the blue-skinned country of Pertania but migrated to the green-skinned country of Cepland when she was 10. She speaks fluent Ceplandic, retains her Pertanian religion and dress, but has mostly adopted Ceplandic attitudes to sex and marriage. Is Lopax Pertanese or Ceplandic? What if she was a mix and had turquoise skin?"