The association between parents’ height and sons’ height: findings from India human development survey (IHDS), 2011–12

While the average height of the Indian population has increased over time, research on the intergenerational relationships in parents’ and children’s heights remains limited. This study investigated the relationship between parental height and sons' height across socioeconomic characteristics in India. Data from the India Human Development Survey 2011–12 (IHDS-2) were analyzed, including 4,939 parent-son pairs. Bivariate analysis and Pearson correlation coefficients examined associations between parents' and sons' heights across socioeconomic variables. Quantile regression models assessed parent and son height relationships at the 0.25, 0.50 and 0.75 quantiles. Multivariate decomposition analysis evaluated contributions to height differences between poor and non-poor populations. Sons' height was significantly associated with parents' height. The results show that a one-year increase in sons’ education is associated with greater height: 1.28 cm (95% CI:0.87, 1.70) at the 25th quantile, 1.30 cm (95% CI: 0.87, 1.73) at the 50th quantile, and 1.22 cm (95% CI: 0.77, 1.67) at the 75th quantile. Pearson correlations revealed moderate associations, with father-son correlations (0.35) slightly stronger than mother-son correlations (0.32). These correlations varied across socioeconomic groups, showing stronger associations among less educated families (0.40) and rural populations. Multivariate decomposition analysis revealed that approximately 73% of the overall height gap between non-poor and poor households was explained by differences in observed characteristics (endowment effect). Among these characteristics, parental height and sons' education were the most significant contributors to the explained portion of the gap. This study reveals that height disparities are primarily driven by differences in family characteristics particularly parental height and educational attainment rather than differential returns to these characteristics. These findings suggest that targeted interventions focusing on improving nutrition and education in poor households could help reduce intergenerational height disparities and promote more equitable human development outcomes.