Longitudinal associations between maternal harsh parenting and child temperament: The moderating role of children's respiratory sinus arrhythmia.

To better understand biology by environment interactions in early temperament, we examined whether children's respiratory sinus arrhythmia (RSA; resting RSA and RSA reactivity) operated as a biological marker of differential susceptibility to maternal harsh parenting in predicting children's temperament. Participants were 133 mother-child dyads (53% male children) from families oversampled for lower income, higher life stress, and child maltreatment risk. Mothers reported harsh parenting at age 3 and children's temperament, including negative affectivity, effortful control, and surgency, at ages 3 and 4. Resting RSA was measured during a 3-min resting task. RSA reactivity was computed as a difference score between a 4-min toy cleanup task and the resting task. Results showed that the interaction between maternal harsh parenting and children's resting RSA significantly predicted negative affectivity, after controlling for sex, household income, and age 3 negative affectivity. Specifically, harsh parenting positively predicted negative affectivity among children with higher, but not lower, resting RSA. Similarly, maternal harsh parenting interacted with children's RSA reactivity to predict negative affectivity after adjusting for controls, such that harsh parenting positively predicted negative affectivity in children with higher, but not lower, RSA reactivity. These findings suggest that higher resting RSA and greater RSA reactivity may operate as markers of increased susceptibility to negative parenting in the development of negative affectivity. (PsycInfo Database Record (c) 2024 APA, all rights reserved).