Perhaps the most compelling finding concerned two hockey teams that had switched to black uniforms during the period the study covered—Pittsburgh in 1980 and Vancouver in 1978-79. The Penguins went from being the 14th most-penalized team (of 17) in the season before the change to black uniforms to seventh most-penalized in the first full season after changing colors—and the NHL had grown to 21 teams by then. The non-black-clad Canucks were ninth most-penalized in the NHL in 1977-78; the Canucks of '78-79 finished third in the same category.
Two possible explanations are that the aggressive acts of black-uniformed teams caused them to be penalized, or that the perception of aggression had the whistles blowing. Penalties come from referees, and referees can be biased. As Gilovich and Frank put it, "They may view any given action as more malevolent if it is performed by a player in a black uniform."
This prejudice is not lost on the players. Terry O'Reilly, coach of the Bruins and a frequent visitor to the penalty box during his own playing days for Boston, says, "I don't think the color of our uniforms has got anything to do with how we play, but it does have a lot to do with how we're perceived. Referees' judgments are based on emotions, and black uniforms may make players look a little more aggressive. That can sway the decision-making process."
One of the experiments that Gilovich and Frank devised to test the hunch that referees are biased against players wearing black involved two separate videos of two football plays. The action was staged as identically as possible in both tapes, but in one version the defensive team wore white, in the other it wore black. Twenty college and high school referees watched the "black" version of the video, and 20 watched the white version. Then, the referees were asked how likely they would be to penalize the defensive team, and "their impression of the teams' 'dirtiness.' "
Sure enough, "the referees were more inclined to penalize the defensive team if they saw the black version...than if they saw the white version." The researchers concluded: "Teams that wear black uniforms receive harsher treatment from the referees."
That prejudice, of course, doesn't mean that players wearing black uniforms play more aggressively, any more than a highway trooper's bias against red cars means that red cars speed more. But real aggression is a tricky thing to test. It's hard to put a black shirt on someone and then figure out if he has become meaner. Nonetheless, this, in effect, is what the researchers tried to do.
To cover up their real intentions, Gilovich and Frank told the subjects of another experiment that they were participating in a study on "the psychology of competition" and that they could choose which events they would compete in by picking five activities from a list of 12. The choice of games ranged from patently aggressive activities—such as dart-gun duels—to basically nonaggressive games such as shooting baskets. Once the subjects had made their choices, they were each given either black or white jerseys and split into two teams. Each team, while wearing the white or black uniforms, had to decide as a group what game it would play.
The two teams never did actually play, because by then the researchers already had the data they were after. The study found that the two groups were indistinguishable in their appetites for aggressive games before they put on the uniforms, but that there was a huge difference afterward. The team with the black shirts wanted to play more violent games. "If the wearing of a black uniform can have such an effect in the laboratory," Gilovich and Frank reasoned, "there is every reason to believe that it would have even stronger effects on the playing field (or rink)."
But how much credit do the the players themselves give their uniforms for increased aggressiveness? Former Bear Hall of Fame linebacker Dick Butkus gives none. "It's too deep for me." he says. "All I know was that we wore dark in the hot weather, dark colors attract heat, and it was uncomfortable."
At the other end of the spectrum, the Bruins' O'Reilly waxes scientific on the subject. "Colors are important." he says. "They project an image. Fast-food joints use yellow and red signs because those colors are supposed to activate the salivary glands; cars sell better when they're jewel colors, like ruby-red and emerald-green; academics wear brown; and businessmen wear navy-blue or dark gray suits."