Inhibitory control moderates the quadratic association between resting respiratory sinus arrhythmia and prosocial behaviors in children.

Resting respiratory sinus arrhythmia (RSA) is thought to be an important physiological correlate of prosocial behaviors. A negative quadratic association between resting RSA and prosocial behaviors has been found in recent studies. However, it remains unknown whether inhibitory control (IC), as an aspect of cognitive regulation, moderates this quadratic association. This issue was examined in the present study. One hundred and forty-eight children (81 girls, 54.7%) aged 7-8 years completed a go/no-go task to assess their IC, and the children's parents completed the Strengths and Difficulties Questionnaire-Chinese version (SDQ-CV) to assess children's prosocial behaviors. Resting RSA was calculated by electrocardiogram (ECG) data collected during a resting period in the laboratory. The results showed a significant quadratic association between resting RSA and children's prosocial behaviors. More importantly, IC had a significant moderating effect on the quadratic association between resting RSA and prosocial behaviors. Specifically, the quadratic effect of resting RSA on prosocial behaviors was observed only among children with low and average IC and disappeared in children with better IC. The findings suggest that IC interacts with resting RSA to contribute to prosocial behaviors in children. High levels of IC could attenuate the negative impact of high and low resting RSA on prosocial behaviors.