A growing number of ERP and fMRI studies is using images of human faces, with both neutral and emotional expressions, as stimuli for the investigation of the neural mechanisms of nonverbal social communication and their impairment in disease (Haxby et al., 2002). Event-related brain activity elicited by facial stimuli has proven itself as a useful indicator of individual differences in processing of socially relevant information and a marker of risk for a number of psychiatric disorders characterized by abnormalities in social cognition and behavior, most notably, autism and schizophrenia (Posamentier and Abdi, 2003). Thus, identification of heritable characteristics of the neural processing of socially relevant facial information can help to elucidate the pathways from genes to individual differences in social behavior, both normal and abnormal. Anokhin et al. (2010) examined genetic influences on the ERPs elicited by facial expressions of emotion using a paradigm in which neutral expression was instantaneously replaced by an emotional expression of the same face. Changes of emotional expression produced two distinct ERP components: N240 wave with a right temporoparietal maximum and a P300 wave with
