Infant biological sensitivity to father engagement in low-income Mexican American families.

Despite a sizeable literature documenting meaningful contributions of father involvement to child health and development, researchers have paid little attention to biological characteristics that may render a child more or less sensitive to fathering behavior. The identification of child and paternal characteristics that promote child behavioral health is particularly critical in the context of sociocultural risk. We hypothesized that respiratory sinus arrhythmia (RSA) measured during infancy would moderate the impact of father engagement in caregiving activities on child behavioral health. In a sample of 181 Mexican American families, we evaluated the impact of infant RSA at 6 weeks, mother- and father-reported father engagement in caregiving activities at 15 and 21 weeks, and their interaction on toddler social or emotional behavior problems and competence at 2 years of age. Only infants with average or higher RSA exhibited more behavior problems in the context of low father engagement (p = .021). Neither RSA nor father engagement predicted behavioral competence. The results are consistent with a stress-diathesis process such that higher infant RSA increases vulnerability to suboptimal father involvement, but does not enhance the benefits of high father involvement.