title: Early television exposure and children's behavioral and social outcomes at age 30 months.
abstract: BACKGROUND
  Previous research has suggested that television (TV) viewing may be associated with increased behavioral and emotional problems in children. However, there are few prospective studies targeted for its association with outcomes of children under 3 years old. The purpose of this study was to exam the association between children's early TV exposure at ages 18 and 30 months and the behavioral and emotional outcomes at age 30 months.
  
  
  METHODS
  We analyzed data collected prospectively in the Japan Children's Study. TV exposure was assessed by mothers' report at infant ages of 18 and 30 months. The outcomes were assessed using the Strengths and Difficulties Questionnaire (SDQ). Analysis of Covariance was used to estimate the effect of TV exposure on behavioral and emotional outcomes.
  
  
  RESULTS
  The percentage of children who watched TV 4 hours or more per day was 29.4% at age 18 months, 24.5% at age 30 months, and 21% at both ages. Hyperactivity-inattention at age 30 months was positively associated with TV exposure at age 18 months, whereas prosocial behavior was negatively associated with hours of exposure even after adjustment. However, there were no significant differences in SDQ subscales according to daily hours of TV viewing at age 30 months.
  
  
  CONCLUSIONS
  Daily TV exposure at age 18 months was associated with hyperactivity-inattention and prosocial behavior at age 30 months. However, the directly casual relation was not proved in the present study. Additional research considering the TV program content and exposure timing are needed to investigate the causal relation between TV viewing and behavioral outcome.
authors.affiliation: Research Institute of Science and Technology for Society, Japan Science and Technology Agency, Tokyo, Japan. cheng@iuhw.ac.jp
authors.forename: Shunyue
authors.initials: S
authors.lastname: Cheng
authors.forename: Tadahiko
authors.initials: T
authors.lastname: Maeda
authors.forename: Sakakihara
authors.initials: S
authors.lastname: Yoichi
authors.forename: Zentaro
authors.initials: Z
authors.lastname: Yamagata
authors.forename: Kiyotaka
authors.initials: K
authors.lastname: Tomiwa
mesh_terms: D000367:Age Factors; D000704:Analysis of Variance; D001289:Attention Deficit Disorder with Hyperactivity / Q000453:epidemiology* / Q000209:etiology; D002653:Child Behavior Disorders / Q000453:epidemiology / Q000209:etiology; D002675:Child, Preschool; D005260:Female; D006801:Humans; D008297:Male; D011446:Prospective Studies; D012919:Social Behavior; D011795:Surveys and Questionnaires; D013690:Television; D013997:Time Factors