Analyzing the neutrality of referees during twelve German premier league (1st Bundesliga) football seasons, this paper documents evidence that social forces influence agents' preferences and decisions. Those, who are appointed to be impartial, tend to favor the home team as they systematically award more injury time in close matches when the home team is behind. Referees also tend to favor the home team in decisions to award goals and penalty kicks. The composition of the crowd affects the size and the direction of the bias. The intensity of social pressure as measured by the crowd's proximity to the field determines how strongly referees' decisions are influenced. Not all agents are, however, affected to the same degree by social pressure.