Public schools are replete with children and adolescents like Billy, Reid, and Rowdy whom teachers describe as rude, disruptive, and obnoxious, and not all of them are in special education. Asher (1990) estimated that 10% of school-age children have social skills deficits severe enough to be rejected by their peers and up to 75% of children with…

Background: Relatively little is known about the genetic architecture of childhood behavioral disorders in very young children. Method: In this study, parents completed the Infant-Toddler Social and Emotional Assessment, a questionnaire that assesses symptoms of childhood disorders, as well as socio-emotional competencies, for 822 twin pairs…