title: A method for the longitudinal study of behavioral development in infants and children: the early development of XXY children.
mesh_terms: D000782:Aneuploidy; D001288:Attention; D002652:Child Behavior; D002657:Child Development; D002675:Child, Preschool; D005824:Genetics, Behavioral; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007360:Intelligence; D007804:Language Development; D007859:Learning Disabilities / Q000453:epidemiology; D008137:Longitudinal Studies; D008297:Male; D009043:Motor Activity; D012107:Research Design; D012730:Sex Chromosomes; D012919:Social Behavior; D014178:Translocation, Genetic