As world cup fever hits the nation, a researcher from the University of Wolverhampton has confirmed something that football fans have long suspected - that referees are swayed by the crowd. Alan Nevill found that the shouts of angry fans can put the referee off penalising the home side. A home game can give a team a big advantage - and Nevill wanted to find out why. He showed a group of qualified referees video footage of tackles from Premier league football matches. Half of the group could hear the crowd, but the other half listened in silence. Nevill asked them to judge whether a foul had been committed or not. And guess what - 15% less tackles were judged to be fouls when the sound was on. This could go a long way to explaining why teams are more successful when playing at their home ground.