An investigation of the difference in measured intelligence between twins and single births.
D000328:Adult; D001722:Birth Order; D001724:Birth Weight; D002648:Child; D005260:Female; D005865:Gestational Age; D006801:Humans; D007226:Infant Mortality; D007360:Intelligence; D007361:Intelligence Tests; D008297:Male; D008423:Maternal Age; D011247:Pregnancy; D014427:Twins