Paternal Involvement in Childcare and Housework and Mothers' Spanking Behavior: The Japanese Longitudinal Survey of Newborns in the 21st Century.

Background: No previous study reported an association of paternal involvement in childcare and housework with maternal physical punishment.

Methods: Using data from the Japanese Longitudinal Survey of Newborns in the 21st century (N = 38,554), we analyzed responses about fathers' involvement in childcare and housework at 6 months and mothers' spanking of children at 3.5 years. Fathers' involvement in childcare and housework was scored and categorized into quartiles. Spanking frequency was asked in the "often", "sometimes", or "not at all" categories. Multivariable-adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for the mothers' often spanking children were computed for the fathers' involvement in childcare and housework. We also stratified the association by fathers' working hours (40-49, 50-59, or ≥60 hours/week).

Results: Among the 16,373 respondents, the proportion of mothers who often spanked their children was 4.8%. Compared with the lowest quartile, a higher frequency of paternal involvement in housework was associated with a lower risk of spanking children (P_trend = 0.001). Adjustment for covariates attenuated the association, but significant association was observed in the 3^rd quartile of paternal involvement in housework (OR 0.77; 95% CI, 0.62-0.96). When the fathers worked fewer than 50 hours a week, a significant negative association was observed between the fathers' frequency of childcare and the likeliness of the mothers' spanking their children (P_trend = 0.02).

Conclusion: The fathers' active involvement in childcare and housework could reduce the mothers' physical punishment for their children.