Abstract
Guided by a biopsychosocial perspective of mothering, this study investigated the interplay among biological (maternal cortisol reactivity), psychological (maternal depressive symptoms), and social (infant emotion and regulation) factors in contributing to early changes in maternal parenting. Participants were 1292 low-income, mother-infant pairs, assessed when the infants were 6-months (T1), 15-months (T2), and 24-months old (T3). Maternal parenting was observed at all assessment points. At T1, infant emotion expression and orienting towards mothers were observed, when maternal cortisol reactivity was assessed. Mothers reported their depressive symptoms at T1. Exploratory factor analysis revealed two parenting factors across time points: positive engagement and negative intrusiveness. Second-order latent growth curve models revealed interactions among maternal cortisol reactivity, depressive symptoms, and child negative emotion/orienting at T1 in predicting intercepts and slopes of two parenting factors. T1 maternal cortisol reactivity was associated with a higher positive engagement intercept for infants having high negative emotion at T1, but a lower positive engagement intercept for infants with low negative emotion at T1, under low T1 maternal depressive symptoms. T1 maternal cortisol reactivity was also related to a lower negative intrusiveness intercept for infants showing high orienting at T1. Longitudinally, maternal cortisol reactivity at T1 predicted a faster decline in positive engagement when infants showed high negative emotion at T1, but a slower decline when infants were less negative at T1. This study reveals a bivalent adaptation process in maternal sensitivity and enhances the current understanding of how biopsychosocial factors contribute to maternal parenting in low-income families.