IntroductionRecent evidence suggests that autonomic nervous system functioning can reflect individual differences in sensitivity to the environment, which in turn moderates the effects of family context on psychopathic and antisocial behaviour. Although some preliminary research suggests that the coordination of the sympathetic (SNS) and parasympathetic (PNS) branches of the autonomic nervous system may reflect sensitivity to environmental influences, the majority of research to date has been limited in its focus on just one branch, and little is known about the effects of parental empathy on a child's psychopathic‐like traits. This study aimed to address this gap by examining if the SNS and PNS jointly moderate the prospective contribution of parental empathy to youth psychopathic‐like traits.MethodsMale and female children (n = 340; age = 8–10 years) from the community completed an emotion regulation task during which their skin conductance level (SCL) and respiratory sinus arrhythmia (RSA) activity were recorded. Parental cognitive, affective, and somatic empathy were reported by the caregivers. The child's psychopathic‐like traits were reported by the caregiver and the child and were reassessed 1 year later.ResultsHierarchical regression indicated that after controlling for child sex, age, and concurrent CU traits, low affective empathy in parents predicted higher CU traits 1 year later in youths who exhibited reciprocal sympathetic activation (i.e., SNS activation along with PNS withdrawal), reflecting their enhanced sensitivity to the environment. No such effects were found for other psychopathic‐like traits.ConclusionsFindings suggest that reciprocal SNS reactivity may be a biological indicator for sensitivity to environmental influence and highlight the importance of examining the interactions among multiple systems to better understand the aetiology of psychopathic traits.