Supportive but biased: Perceptual neural intergroup bias is sensitive to minor reservations about supporting outgroup immigration

While decreasing negative attitudes against outgroups are often reported by individuals themselves, biasedbehaviour prevails. This gap between words and actions may stem from unobtrusive mental processes that couldbe uncovered by using neuroimaging in addition to self-reports. In this study we investigated whether addingneuroimaging to a traditional intergroup bias measure could detect intersubject differences in intergroup biasprocesses in a societal context where opposing discrimination is normative. In a sample of 43 Finnish students,implicit behavioural measures failed to indicate intergroup bias against Middle Eastern and Muslim immigrants,and explicit measures reported rather positive attitudes and sentiments towards that targeted group. Yet, whileimplementing a repeatedly validated method for detecting intergroup bias, an implicit association paradigmpresenting stereotypical ingroup and outgroup face stimuli while undergoing magnetoencephalography, wedetected a clear neural difference between two experimental conditions. The neural effect is thought to reflectintergroup bias in the valence of the associations that faces evoke. The activity cluster of the neural bias peakedin BA37 and included significant activity in the fusiform gyrus, which has been repeatedly found to be activeduring face perception bias. Importantly, this neural pattern was driven by participants who were explicitlyfavourable of immigration – but to a lesser extent than others. These findings suggest that such variations inexplicit support of immigration are associated with the differential neural sensitivity to the congruency of as-sociations between intergroup faces and valence. This research showcases the potential of neuroimaging tounravel covert perceptual bias against outgroup members and its sensitivity to small variations in explicitattitudes.