Distinguishing shyness and sociability in adults: An event-related electrocortical-neuroendocrine study

•Shyness and sociability are separable on neurocognitive attentional indices to novelty.•Shyness is related to reduced frontal P3 amplitudes to novelty.•Changes in the neuroendocrine system of shy adults may be linked to central attentional states.•Low basal cortisol mediates the link between shyness and low novelty P3 amplitudes.•Low basal cortisol mediates the link between shyness and emotional arousal.