LONDON (Reuters) - The color of a judoka’s suit plays no part in the outcome of a match, British researchers say.
Previous studies showing blue judo uniforms provided a competitive edge over white ones were flawed, the researchers said on Wednesday.
An examination of 501 gold-medal finals in international competitions between 1996 and 2005 showed that the color of the uniform worn by the winner was split evenly between blue and white, the study found.
“We focused on judo but the finding may have wider implications for sports in general,” said Peter Dijkstra, an behavioral biologist at the University of Glasgow, who led the study. “We show there is no color association for a winning bias.”
Past studies had suggested that contestants in blue had an advantage because the color was more intimidating, or that the white competitor might be more visible, allowing an opponent to better anticipate his movements.
However, Dijkstra said those studies did not take into account that higher seeded — and therefore more skilled — competitors wore the blue uniforms. So it made sense that they would win more often, he said.
Previous research also looked at the loser’s bracket, which could have skewed the results because competitors who lost early were likely to have less confidence and be more prone to another defeat, Dijkstra said.
In the study published in the Proceedings of the Royal Society of Biological Sciences, Dijkstra and colleagues adjusted for these factors by factoring in only gold-medal matches.
“Seeded athletes are top ranked and have a very high chance of winning,” he said in a telephone interview. “They are more likely to wear blue so this automatically creates a winning bias. Athletes in blue are simply better.”
The researchers looked only at judo but said the findings would likely be the same in other individual combat sports such as wrestling, boxing and taekwondo.
The same might hold true for team sports, though factors such as the number of players on a field or court could affect visibility and make color less important, Dijkstra said.
The findings could also help to ensure a more level playing field in other combat sports in which a competitor wore red — a color associated with dominance, fear and aggression that actually might confer an advantage, the researchers added.
“Our findings have implications for sports policy makers: they suggest that white-blue outfit pairing ensures an equal level of play,” the researchers wrote.
Editing by Maggie Fox and Clare Fallon