Assortative mating with respect to physical characteristics.
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000886:Anthropometry; D005075:Biological Evolution; D001827:Body Height; D001835:Body Weight; D005260:Female; D005298:Fertility; D005828:Genetics, Population; D006801:Humans; D008297:Male; D008393:Marriage; D008875:Middle Aged