This study investigated whether the nurturing hypothesis – that breastfeeding serves as a proxy for family socio-economic characteristics and parenting behaviours – accounts for the association of breastfeeding with children's academic abilities. Data used were from the Child Development Supplement of the Panel Study of Income Dynamics, which followed up a cohort of 3563 children aged 0–12 in 1997. Structural equation modelling simultaneously regressed outcome variables, including three test scores of academic ability and two subscales of behaviour problems, on the presence and duration of breastfeeding, family socio-economic characteristics, parenting behaviours and covariates. Breastfeeding was strongly related to all three tests scores but had no relationships with behaviour problems. The adjusted mean differences in the Letter–Word Identification, Passage Comprehension) and Applied Problems test scores between breastfed and non-breastfed children were 5.14 [95% confidence interval (CI): 3.14, 7.14], 3.46 (95% CI: 1.67, 5.26) and 4.24 (95% CI: 2.43, 6.04), respectively. Both socio-economic characteristics and parenting behaviours were related to higher academic test scores and were associated with a lower prevalence of externalising and internalising behaviour problems. The associations of breastfeeding with behaviour problems are divergent from those of socio-economic characteristics and parenting behaviours. The divergence suggests that breastfeeding may not be a proxy of socio-economic characteristics and parenting behaviours, as proposed by the nurturing hypothesis. The mechanism of breastfeeding benefits is likely to be different from those by which family socio-economic background and parenting practices exert their effects. Greater clarity in understanding the mechanisms behind breastfeeding benefits will facilitate the development of policies and programs that maximise breastfeeding's impact.
Bibliographical noteFunding Information:
The authors are grateful for support from the Meadows Center for Preventing Educational Risk, the Institute on Educational Sciences grants (R324A100022 and R324B080008) and from the Eunice Kennedy Shriver National Institute of Child Health and Human Development (P50 HD052117).
All Science Journal Classification (ASJC) codes
- Pediatrics, Perinatology, and Child Health
- Obstetrics and Gynaecology
- Nutrition and Dietetics
- Public Health, Environmental and Occupational Health