Relations between early maternal sensitivity and toddler self‐regulation: Exploring variation by oxytocin and dopamine D2 receptor genes

Gene‐by‐environment interactions between maternal sensitivity during infancy and child oxytocin receptor gene (OXTR rs53576) and D2 dopamine receptor gene (DRD2 TaqIA, rs1822497) genotypes were explored as predictors of toddlers’ well‐regulated behavioral and physiological responses to maternal compliance demands. Maternal sensitivity was assessed across a range of mother–child interactions when children were 6 months and 1 year of age (N = 186), and toddler self‐regulatory responses were assessed through compliance and vagal withdrawal during a toy clean‐up task when children were 2 years of age. Sensitivity‐by‐OXTR interactions suggested two diathesis‐stress patterns, predicting compliance for the GG genotype group, and predicting physiological regulation for the AA/AG genotype group. A main effect for DRD2 genotype indicated that children with an A1 allele displayed less‐compliant behavior in toddlerhood. These results suggest that genetic differences may contribute to variation both in risk for self‐regulatory difficulties, and in relations between maternal sensitivity and children's responses to compliance demands at different levels of analysis.