Respiratory sinus arrhythmia, shyness, and effortful control in preschool-age children

► Preschool-aged sample. ► Multiple methods used to measure effortful control (EC) and shyness. ► Tested the interaction of respiratory sinus arrhythmia × shyness as predictor of EC. ► Respiratory sinus arrhythmia related to EC only for children high in shyness. ► Importance of context for resting physiological recordings is emphasized.