title: Assortative mate choice and mating opportunity on Sanday, Orkney Islands.
mesh_terms: D000293:Adolescent; D000328:Adult; D001722:Birth Order; D003241:Consanguinity; D005191:Family Characteristics; D005260:Female; D006801:Humans; D008297:Male; D008393:Marriage; D008875:Middle Aged; D012606:Scotland; D012923:Social Class