Uriah

D helps protect Irishmen against rickets and inflammatory diseases, but an expected benefit of the selection was this it provided them with a stronger immunity to schizophrenia than any other North European people. Psychotism is a plus if your body can handle it and they could.

About ¼ of Mormons have Scandinavian surnames, principally Danish and Norwegian, and I think the low hanging cluster of dots on the bottom of CEU represents individuals of majority Scandinavian descent that I know to exist in the dataset.

Scandinavians are under strong selective pressure to keep schizophrenia low, but their high consumption of fish both reduces the power of that pressure and redirects it away from acting directly upon schiz causing alleles and instead improving omega-3 metabolism instead.

The population that has probably been under the most ruthless selection again schiz per se are the Finns, who along with their Estonian cousins have the highest PISA scores in Europe. Pfiffer also calculated them as having highest the Edu Attainment PGS of any Europeans.