The truth below the surface: towards quantifying and understanding the evaluation of German and Danish hate speech with EEG biosignals

The recipient is a stimulus-external factor that has so far hardly been investigated in hate-speech research. However, addressing this factor is essential to understand how and why hate speech unfolds its negative effects and which characteristics of the recipient influence these effects. The present study focuses on the recipient. Building on previous findings from explicit ratings and initial successful replications of such ratings through biosignals, we are conducting the first large-scale, systematic, and cross-linguistic biosignal study on hate speech based on two EEG measures: the beta-alpha ratio associated with arousal and the frontal alpha asymmetry associated with valence. A total of 50 Danish and German participants took part and were presented with spoken and written hate-speech stimuli, derived from authentic hate-speech posts on Twitter. Results show that Danes reacted more sensitively than Germans to hate speech containing figurative language (swear words), while Germans reacted more sensitively to hate speech with Holocaust references than Danes. In addition, teachers and lawyers showed less negative reactions to hate speech than church employees, students, and pensioners. The effect of the presentation medium depended on the respective hate speech type. In particular, speaking out hate speech based on irony and indirectness attenuated its effects on recipients to such an extent that it is questionable whether the stimuli were still perceived as instances of hate speech at all. We discuss the results in terms of key tasks of future studies and practical implication for the punishment and management of hate speech on social media.