title: Precursors to aggression are evident by 6 months of age.
abstract: We tested the hypothesis that developmental precursors to aggression are apparent in infancy. Up to three informants rated 301 firstborn infants for early signs of anger, hitting and biting; 279 (93%) were assessed again as toddlers. Informants' ratings were validated by direct observation at both ages. The precursor behaviours were significantly associated with known risk factors for high levels of aggressiveness. Individual differences were stable from early infancy to the third year and predicted broader conduct problems. These findings suggest that some individuals set forth on the trajectory to high levels of aggression by 6 months of age. The findings have implications for developmental studies of aggression, clinical prevention and intervention strategies, and theoretical considerations regarding the detection of precursors in different domains of development.
authors.affiliation: School of Psychology, Cardiff University, UK.
authors.forename: Dale F
authors.initials: DF
authors.lastname: Hay
authors.forename: Cerith S
authors.initials: CS
authors.lastname: Waters
authors.forename: Oliver
authors.initials: O
authors.lastname: Perra
authors.forename: Naomi
authors.initials: N
authors.lastname: Swift
authors.forename: Victoria
authors.initials: V
authors.lastname: Kairis
authors.forename: Rebecca
authors.initials: R
authors.lastname: Phillips
authors.forename: Roland
authors.initials: R
authors.lastname: Jones
authors.forename: Ian
authors.initials: I
authors.lastname: Goodyer
authors.forename: Gordon
authors.initials: G
authors.lastname: Harold
authors.forename: Anita
authors.initials: A
authors.lastname: Thapar
authors.forename: Stephanie
authors.initials: S
authors.lastname: van Goozen
mesh_terms: D000367:Age Factors; D000374:Aggression / Q000523:psychology*; D000786:Anger / Q000502:physiology; D002657:Child Development / Q000502:physiology*; D006801:Humans; D007231:Infant, Newborn; D008137:Longitudinal Studies; D008425:Maternal Behavior / Q000523:psychology; D008960:Models, Psychological; D019370:Observation; D011446:Prospective Studies; D012307:Risk Factors; D012959:Socioeconomic Factors