In most areas of society, the phenomenon of social pressure on the behaviour of individuals has always played a critical role and affects the outcome of important events. One of the environments in which the phenomenon of social influence and pressure is most evident is sport: the preferences of a particular group, the crowd at a football match, can in fact greatly influence the referee’s behaviour and decisions. In this paper, we will report a brief summary of the literature about the social influence in general, and about the social pressure exerted on a referee in particular. We will then report some studies that have looked at empirical evidence on the social pressure exerted on a referee: these studies have analyzed the number of yellow and red cards given on average against the home team and against the visiting team, the frequency with which penalties are awarded to the home and visiting teams and the decision of how much recovery time will be given at the end of normal time.
