title: The etiology of behavioral problems and competencies in very young twins.
abstract: Although genetic and environmental influences on behavior problems in middle childhood and adolescence have been well-studied, little is known about the etiology of behavior problems in very early childhood. The present study explores genetic and environmental contributions to individual differences in behavior problems and competences in an infant-toddler sample of twins. There were 1,950 twin pairs (mean age=23.8 months) who were rated by parents on the Infant-Toddler Social and Emotional Assessment. All four domains (Externalizing, Internalizing, Dysregulation, Competence) and 20 subscales-indices on the Infant-Toddler Social and Emotional Assessment displayed significant heritability. There were also substantial shared environmental influences operating on most of the domains and subscales. Compared with behavior problems, behavioral competencies were less heritable and more influenced by shared environments.
authors.affiliation: Department of Psychology, Boston University, Boston, MA 02215, USA. ksaudino@bu.edu
authors.forename: Kimberly J
authors.initials: KJ
authors.lastname: Saudino
authors.forename: Alice S
authors.initials: AS
authors.lastname: Carter
authors.forename: Diane
authors.initials: D
authors.lastname: Purper-Ouakil
authors.forename: Philip
authors.initials: P
authors.lastname: Gorwood
mesh_terms: D000124:Achievement; D002653:Child Behavior Disorders / Q000453:epidemiology* / Q000235:genetics*; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007398:Interpersonal Relations; D008297:Male; D015588:Observer Variation; D011795:Surveys and Questionnaires; D014427:Twins / Q000235:genetics*