The Dynamic Nature of Group Membership: Assessing the Effects of Grouping Cues on Social Perception

Humans have a rapid and automatic tendency to categorize others based on their similarities, breaking the world into “us” and “them.” These similarities can be physical, such as skin color or gender, or can be non-physical, such as religious or political affiliation. These in-group and out-group distinctions lead to a variety of cognitive and behavioral discrepancies. For example, decades of research has demonstrated that other-race individuals are recognized less accurately than own-race individuals, a phenomenon known as the “Other-Race Effect” (ORE). What is less clear is whether these processing discrepancies are unique to racial categories, or whether other indicators of category membership can have a similar impact. In this dissertation, I examined neural activation associated with the processing of in-group and out-group members on both physical and non-physical dimensions. In the first three experiments, the impacts of group membership cues on early stages of face processing were examined by measuring event-related potentials (ERPs) using electroencephalography (EEG). Results indicate that although both physical and non-physical cues impact early face processing, they do so at different stages. Furthermore, physical cues impact face processing even when irrelevant to the given task. In the final experiment, functional magnetic resonance imaging (fMRI) methods were used to show that perceived group membership impacts biological motion perception. Collectively, the data suggest that group membership is malleable, and influences both perception and cognition. I suggest that motivated perception impacts very early stages of processing based on task-relevant grouping cues and these cues can interact with task-irrelevant cues, impacting both early encoding and subsequent recognition of others.