Distinguishing shyness and sociability in children: An event-related potential study.

Shyness and sociability are independent personality dimensions, each with distinct behavioral and psychophysiological correlates that are conserved across development, culture, and phylogeny. However, relatively little is known regarding how shyness and sociability are instantiated in the brain, particularly during childhood and during the processing of nonsocial stimuli. Using a three-stimulus auditory oddball task, we examined whether variations in shyness and sociability were related to the N200 and P300 event-related potential (ERP) brain responses to processing task-relevant, novel, and standard auditory tones in 53 typically developing 10-year-old children. ERP amplitudes were measured at four midline scalp sites: Fz, FCz, Cz, and Pz. We found that increases in shyness were correlated with increases in target P300 amplitudes across all four head sites, increases in standard P300 amplitudes, and decreases in target P300 latencies in anterior sites. No relations were found for sociability and P300 responses. We also found that P300 amplitude in the frontal region to standard tones mediated the relation between conflicted shyness (i.e., high shyness and high sociability) and emotional instability. These results suggest that shyness and sociability are distinguishable on neurocognitive measures and that these neurocognitive measures may be putative mechanisms in understanding risk for emotional instability and a broad range of dysregulated behavioral problems observed in individuals characterized by conflicted shyness.