Moderate Heart Rate Variability Is Associated with Empathic Responses to Parents’ Happiness

High-frequency heart rate variability (HF-HRV) at rest was quadratically associated with affective positive empathy but not affective negative empathy or cognitive empathy during a parent-child interaction paradigm. Moderate HF-HRV may reflect flexible interplay between affective reactivity and regulated control that supports children’s capacity for empathic happiness toward parents.