title: Genetic aspects of temperamental differences in infants. A study of same-sexed twins.
mesh_terms: D002657:Child Development; D005260:Female; D005824:Genetics, Behavioral; D006801:Humans; D007223:Infant; D008297:Male; D010551:Personality; D010553:Personality Development; D011247:Pregnancy; D013694:Temperament; D014427:Twins