title: Toddler and childhood temperament: expanded content, stronger genetic evidence, new evidence for the importance of environment.
abstract: Using samples of twins and singletons totaling 715 individuals, the authors document heritable influences on various temperamental dimensions during the toddler and preschooler age ranges, which have been somewhat understudied relative to infants and older adolescents. In contrast to instruments on which prior literature is based, the Toddler Behavior Assessment Questionnaire and the Children's Behavior Questionnaire offer assessment of positive affectivity (separately from negative affectivity) and of emotional regulation. Positive affect reveals substantial shared environmental influence, and emotion regulation reveals additive genetic influence. Evidence for genetic variance in temperament is strengthened because intraclass correlations from many of these questionnaire scales show no evidence of "too-low" dizygotic correlations that imply contrast effects. Suggestive evidence is offered that psychometric characteristics of the questionnaires can affect biometric inferences.
authors.affiliation: Department of Psychology, University of Wisconsin-Madison 53706, USA. hhgoldsm@facstaff.wisc.edu
authors.forename: H H
authors.initials: HH
authors.lastname: Goldsmith
authors.forename: K A
authors.initials: KA
authors.lastname: Buss
authors.forename: K S
authors.initials: KS
authors.lastname: Lemery
mesh_terms: D002648:Child; D002657:Child Development; D002675:Child, Preschool; D004777:Environment; D005260:Female; D005824:Genetics, Behavioral; D006801:Humans; D007223:Infant; D008297:Male; D010552:Personality Assessment; D013694:Temperament