To estimate the influence of early childhood television exposure on fourth-grade academic,
psychosocial, and lifestyle characteristics.
Prospective longitudinal study.
Institut de la Statistique du Québec, Québec, Canada.
A total of 1314 (of 2120) children. Main Exposure Parent-reported data on weekly hours
of television exposure at 29 and 53 months of age. We conducted a series of ordinary
least-squares regressions in which children's academic, psychosocial, and lifestyle
characteristics are linearly regressed on early and preschool television exposure.
Parent and teacher reports of academic, psychosocial, and health behaviors and body
mass index measurements (calculated as weight in kilograms divided by height in meters
squared) at 10 years of age.
Adjusting for preexisting individual and family factors, every additional hour of
television exposure at 29 months corresponded to 7% and 6% unit decreases in classroom
engagement (95% confidence interval [CI], -0.02 to -0.004) and math achievement (95%
CI, -0.03 to 0.01), respectively; 10% unit increases in victimization by classmates
(95% CI, 0.01 to 0.05); 13% unit decreases in time spent doing weekend physical activity
(95% CI, 0.81 to 2.25); 9% unit decreases in activities involving physical effort
(95% CI, -0.04 to 0.00); higher consumption scores for soft drinks and snacks by 9%
and 10% (95% CI, 0.00 to 0.04 and 95% CI, 0.00 to 0.02), respectively; and 5% unit
increases in body mass index (95% CI, 0.01 to 0.05). Preschool increments in exposure
also made a unique contribution to developmental risk.
The long-term risks associated with higher levels of early exposure may chart developmental
pathways toward unhealthy dispositions in adolescence. A population-level understanding
of such risks remains essential for promoting child development.