Parental leadership in motion: neural and behavioral mechanisms of synchrony during parent-child interaction.

Parent-child synchrony, the coordination of movements and goals between parents and children, plays a vital role in social development, yet its neural mechanisms and leadership dynamics remain unclear. Using functional near-infrared spectroscopy hyperscanning, 33 parent-child dyads (children 8-15 years) played a tablet-based game ("The Flocking Game") under spontaneous and intentional synchrony instructions. Results revealed that dyads exhibited behavioral synchrony values significantly greater than zero (with zero reflecting no synchrony) even without instruction, and synchrony increased when coordination of movement was explicitly required. Parents led more during spontaneous play, reflecting their natural regulatory role, whereas leadership equalized under intentional instructions. Neural analyses revealed significant inter-brain synchrony across the dorsolateral prefrontal cortex (DLPFC), inferior frontal gyrus (IFG), and inferior parietal lobule (IPL). In the intentional condition, stronger parent left-DLPFC coupling with the child IFG or IPL predicted greater behavioral synchrony, while spontaneous synchrony was linked to parent IPL-child IFG synchrony. These results suggest that spontaneous synchrony relies on mirroring within the action observation network, whereas intentional synchrony engages executive control, highlighting complementary neural pathways through which parental leadership shapes goal-directed interaction.