Behavioral differences have been reported between conservatives and liberals when categorizing facial expressions, yet no study explores potential differences in the manner in which the two groups process facial expressions, let alone how partisanship contributes or how political engagement may vary with brain processing of facial expressions. In this context, processing refers to brain patterns following exposure to a facial expression and participants’ subsequent attention to the presented facial expressions. This thesis addresses the question of whether political temperament is associated with differences in neural processing. Research subjects participated in an emotion discrimination task while event-related potentials (ERP) were captured in order to explore the neurological processing similarities and differences between conservatives and liberals (also by accounting for partisanship), and those with varying levels of participation, in response to the facial expressions of fear, happiness, anger, disgust, and no emotion (neutral). The findings suggest that, for the P2 component, compared to liberals, conservatives process facial emotions more rapidly but only for particular categories of emotion. When including partisanship in a model, more pronounced differences emerge, with ideology emerging as a factor that captures facial processing differences irrespective of emotion. In terms of participation, those who tend to participate less have higher P1 amplitudes, indicating large cognitive resources spent to process facial information, and also tend to have higher cortisol levels.
Adviser: John H. Hibbin