Frequency of Organised Enrichment Activities and Later Self‐Esteem in Japanese Children: A Longitudinal Cohort Study

Background Although participation in organised extracurricular activities has been associated with higher self‐esteem, high participation frequency may have adverse effects, as proposed by the overscheduling hypothesis. Longitudinal evidence from non‐Western countries is limited. We examined whether the frequency of enrichment‐oriented out‐of‐school lessons (naraigoto) in fourth grade was associated with self‐esteem in sixth grade in a Japanese large‐scale cohort. Methods We analysed longitudinal data from the Japanese Longitudinal Study of Children and Parents from fourth grade (baseline, 2017–2019) to sixth grade (follow‐up, 2019–2021) ( n = 3399). The exposure was the frequency of enrichment‐oriented activities in fourth grade, excluding academic tutoring (juku). The outcome was self‐confidence in sixth grade (4‐point Likert scale). Ordinal logistic regression models were employed for estimating odds ratios and 95% confidence intervals, and possible confounders (sociodemographic factors, baseline self‐confidence) were adjusted. Sensitivity analyses were also conducted using alternative outcome and alternative exposure definitions. Results In the fully adjusted model, the adjusted odds ratios for higher self‐confidence were 1.22 (95% confidence interval 0.96–1.55) for one session/week, 1.30 (1.02–1.66) for two sessions/week, 1.34 (1.04–1.73) for three session/week, 1.41 (1.10–1.82) for four to five sessions/week, and 1.22 (0.87–1.71) for six or more sessions/week, compared with zero sessions/week (reference). Associations were strongest at two to five sessions/week, with no increase at six or more sessions/week. Results were similar in sensitivity analyses. Gender‐stratified analyses suggested that these associations were significant only in male participants. Conclusions Enrichment activity participation was associated with self‐esteem 2 years later, with the strongest associations at moderate frequencies. Future studies should examine total amount of time and qualitative aspects of participation.