title: Longitudinal patterns of heart rate and fighting behavior in 9- through 12-year-old boys.
abstract: OBJECTIVE
  To assess the temporal stability of heart rate and to examine its relationship with fighting behavior.
  
  
  METHODS
  Heart rate at ages 9 through 12 was compared to a composite measure of fighting behavior in three cohorts of low socioeconomic status boys (n = 138; two cohorts of boys who had been rated as having disruptive behavior problems in kindergarten and one normative cohort) while controlling for body size, pubertal status, and level of family adversity.
  
  
  RESULTS
  Heart rate showed moderate stability at 1- and 2-year intervals in two of the three cohorts. The composite fighting score was related to heart rate for 11-year-old boys in the normative cohort and 12-year-old boys in one of the disruptive cohorts.
  
  
  CONCLUSIONS
  These data support the conclusion that there is a relationship between heart rate and aggression even within a low socioeconomic status sample.
authors.affiliation: Developmental Epidemiology Research Unit, Judge Baker Children's Center, Boston, MA.
authors.forename: D J
authors.initials: DJ
authors.lastname: Kindlon
authors.forename: R E
authors.initials: RE
authors.lastname: Tremblay
authors.forename: E
authors.initials: E
authors.lastname: Mezzacappa
authors.forename: F
authors.initials: F
authors.lastname: Earls
authors.forename: D
authors.initials: D
authors.lastname: Laurent
authors.forename: B
authors.initials: B
authors.lastname: Schaal
mesh_terms: D000374:Aggression / Q000502:physiology*; D016009:Chi-Square Distribution; D002648:Child; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D011792:Quebec / Q000453:epidemiology; D012044:Regression Analysis; D012307:Risk Factors; D012959:Socioeconomic Factors