On Thin Ice

Past research suggests that wearing either a black or a red uniform leads to increased aggression or an increase in perceived aggression during professional sports. However, this research suffers from a number of limitations, including an inability to manipulate the independent variable. A recent change in the National Hockey League’s uniform policy created the possibility of a naturally occurring experiment that allowed the authors to examine whether aggression levels were higher when teams wore black or red jerseys. The authors compared games against the same opponent in which home teams wore red or black jerseys for one game and their usual color for another game on several measures of aggression. They found no evidence that either black or red uniforms were related to higher levels of aggression in professional hockey games.