The Association between Breastfeeding Duration and Attachment: A Genetically Informed Analysis

Introduction: A growing body of research explores whether breastfeeding during infancy influences the development of attachment security in offspring. Studies to date have generally yielded inconsistent results, with some studies detecting an association between breastfeeding and attachment security, and others failing to do so. The purpose of this study is to empirically consider whether (1) any association between breastfeeding and offspring attachment security is robust to both familial and genetic confounding and (2) whether the breastfeeding-attachment relationship is significant for both male and female offspring. Materials and Methods: The present study uses data from the Early Childhood Longitudinal Study: Birth Cohort (ECLS-B) to examine whether twins who differ in their extent of exposure to breastfeeding exhibit different attachment patterns by the time they reach toddlerhood. Results: The results suggest that, independent of genetic and shared environmental influences, breastfeeding duration increases the security of attachment in offspring, but only among females. Conclusions: A longer duration of breastfeeding may help to facilitate a secure attachment among female offspring.