Meanness and Affective Processing: A Meta-Analysis of EEG Findings on Emotional Face Processing in Individuals with Psychopathic Traits

The triarchic model (Patrick, Fowles, & Krueger, 2009) conceptualizes psychopathy as a multidimensional construct encompassing three biobehavioral dimensions: meanness, boldness, and disinhibition. The biological correlates of meanness, which encompasses low empathy, shallow affect, and lack of guilt or remorse, are currently less well elucidated than boldness or disinhibition (Patrick & Drislane, 2015). At the behavioral level, meanness is related to decreased accuracy on tasks involving facial and emotion recognition (Brislin et al., 2018). Emotional face processing can be examined on a neurophysiological level using event-related potentials (ERPs) such as N170, P200, and LPP (Shannon et al., 2013). Research indicates the magnitude of these responses may be modulated by psychopathic meanness (Clark et al., 2019); however, discrepant findings have also been reported. Therefore, the current study performed random-effects model meta-analyses of nine studies meeting study inclusion criteria to provide an overall effect size for the association between meanness and affective face processing ERPs across studies. Results of the meta-analysis indicated a significant effect for N170 amplitude and meanness when processing fearful faces (r = 0.18). Significant effects were not found for N170 amplitude when processing angry or happy faces, nor were significant effects found for LPP and P200 amplitudes when processing fearful faces. Meta-regression analyses indicated the type of facial stimuli utilized across studies was significant in explaining some between-study heterogeneity of the N170-fear meta-analysis model. Through examining physiological indicators of meanness, the current study contributes to ongoing research on the etiology of psychopathy and may guide future research in establishing a multi-domain framework for the measurement of psychopathy.