Children's Media Use and Self-Regulation Behavior: Longitudinal Associations in a Nationwide Japanese Study.

Objective The effect of media use on child behavior has long been a concern. Although studies have shown robust cross-sectional relations between TV viewing and child behavior, longitudinal studies remain scarce. Methods We analyzed the Longitudinal Survey of Babies, conducted by Japan's Ministry of Health, Labour and Welfare since 2001. Among 53,575 families, 47,010 responded to the baseline survey; they were followed up every year for 8 years. Complete data were available for longitudinal analysis among 32,439 participants. Daily media use (TV viewing and video game-playing hours at ages 3, 4, and 5 years) was used as the main exposure. We employed an index of the children's self-regulatory behavior as the outcome variable. Odds ratios and 95 % confidence intervals (CIs) were estimated. Results Among boys, longer TV-viewing times at ages 4 and 5 were related to problematic self-regulatory behavior. Compared with boys who watched just 1-2 h of TV a day, those who watched it 4-5 h had a 1.79-fold greater risk (CI 1.22-2.64) of problematic self-regulatory behavior, according to parental report. Among girls, similar results were evident at ages 4 and 5 (e.g., adjusted odds ratios for 4-5 h daily viewing versus 1-2 h at age 4: 2.59; 95 % CI 1.59-4.22). Video games may have a protective effect on the risk of problematic self-regulatory behavior at ages 3 and 5. Conclusion Longer daily exposure to TV during early childhood (age 4-5) may be associated with subsequent problematic child self-regulatory behavior.