The study of mental ability using twin and adoption designs.
D000300:Adoption; D000328:Adult; D002648:Child; D003878:Dermatoglyphics; D005260:Female; D005824:Genetics, Behavioral; D006801:Humans; D007360:Intelligence; D008297:Male; D008957:Models, Genetic; D011247:Pregnancy; D012737:Sex Factors; D012959:Socioeconomic Factors; D014427:Twins