The attire of competitors playing combat sports at the 2004 Olympic Games is the unlikely subject of a sparring session between biologists in
Previous research has suggested that the color of team uniforms can influence the players wearing them—for instance, players who wear black tend to be more aggressive. In May, 2005, Russell Hill and Robert Barton from Durham University, UK, took it a step further. They released an analysis of the results of combat sports -- boxing, tae kwon do, Greco-Roman wrestling and freestyle wrestling -- at the Athens Olympics, showing that contestants who had been randomly assigned red outfits were more likely to beat those wearing blue. As reported in
Red coloration is widely used by male animals to attract mates and intimidate rivals, they argued. Hill told
Now, Candy Rowe of the UK's University of Newcastle and colleagues offer a different explanation. From the same Olympics, they studied judo uniforms, a sport in which neither competitor wears red. This week, they report in
"There's a lot of merit to both proposals," said Geoffrey Miller, an evolutionary psychologist at the University of New Mexico, Albuquerque, who was involved in neither study. He added that he is impressed that Hill and Barton found an effect of color in male, but not female, competitors, a finding that appears to support their evolutionary model.
Roland Carlstedt, chair of the American Board of Sport Psychology, who has already criticized the design of Hill and Barton's original study, is equally scathing of the new one. "Non-parametric and post-hoc retrospective analyses are at the lowest level in the evidence hierarchy," he told
And not all bookmakers took stock in the findings, either. After Hill and Barton's original study, a spokesperson for William Hill, one of the world's largest betting companies (and no relation to Russell Hill) told
In a response to Rowe et al's work, also published this week, Hill and Barton defend their theory, arguing that blue is used as a signal of "long-term developmental vigor" in species such as mandrills, and may, therefore, also confer psychological advantages compared with paler colors.
But Rowe is concerned that other animals – dominant silverback gorillas, for example - could also bolster the evolutionary interpretation had white been found to carry an advantage over blue. "Evolutionary psychology has often been criticized for building stories around data sets without considering the alternatives," she said.
Rowe agreed with criticisms that experiments are required to test the effects of different colored outfits on detection and reaction times of opponents. And Hill noted that he and Barton plan to measure the effects of outfit color on competitors' levels of testosterone, which mediates aggressive displays in other animals.