Religious rituals have been theorized to help produce social solidarity amongst group members, as well as hostility towards out-groups. Recent empirical research has started to examine specific aspects of collective rituals (e.g. synchronous movement) that might be important in modulating attitudes and behaviour towards the in-groups and the out-groups. Many religious rituals involve highly arousing stimuli and literature suggests that arousal can alter (mainly amplify) various emotions. For example, it has been shown in laboratory settings that at the individual level arousal can produce residual excitement that serves to intensify later emotional states like aggression, sexual attraction or humour appreciation. Recent field studies, concentrating with greater ecological validity on the collective dimension of arousal, show that participants as well as spectators of religious rituals can share arousal to a great extent, and that highly arousing rituals can promote pro-social behaviour. However, it is yet to be established how arousal may influence prosociality and under what conditions arousal may produce pro-social effects. My presentation discusses results of the recent study I conducted in controlled laboratory conditions in Brno, Czech Republic. The key research question addressed was whether (given the right prime) physiological arousal can influence social behaviour. More specifically, whether physiological arousal (given the right conditions for excitation transfer to occur) will result in increased pro-social or anti-social behaviour (given the right prime). My rationale is based on the Excitation transfer theory from previous psychological research which states that, if certain conditions are met, arousal elicited by one stimulus can be mistakenly attributed to another. Here, I experimentally tested using video games as stimulus, whether autonomic arousal can alter (amplify) even more complex states, be they pro-social or anti-social.