A reply to Heath et al. On assortative mating for educational level.
D000293:Adolescent; D000328:Adult; D004522:Educational Status; D005260:Female; D005824:Genetics, Behavioral; D006801:Humans; D007360:Intelligence; D008297:Male; D008393:Marriage; D008875:Middle Aged; D012937:Social Mobility; D014427:Twins