Smiling after witnessing provocateur's suffering: a facial electromyography study

Previous research has shown that people derive pleasure from witnessing a provocateur suffer from retaliatory punishment, as indicated by increased activation of the zygomaticus major (ZM) and orbicularis oculi (OO) muscles, along with decreased activation of the corrugator supercilii (CS) muscle. This study examined whether participants (N = 43) would exhibit similar facial reactions when observing a competitor's suffering from punishments administered by a computer rather than by themselves. Results showed that participants smiled (increased ZM and OO activity, decreased CS activity relative to baseline) when observing a provocative competitor in pain compared to when he was not in pain, indicating a pleasurable response. In contrast, they frowned (decreased ZM and OO activity, increased CS activity relative to baseline) when observing a non-provocative competitor in pain, indicating an empathetic concern. These findings suggest that the perception of harm-doing is a critical determinant of schadenfreude in vengeful social interactions.