Are You on the Red Team or the Blue Team?

Among male participants in a competition experiment, those who chose to represent themselves with red trapezoidal symbols on a scoreboard proved to have blood-testosterone levels that were about 10% higher than those who chose blue trapezoidal symbols, says a team led by Daniel Farrelly of the University of Sunderland in the UK. Those who chose red didn’t perform any better on the competitive task, however. It’s unclear whether the color choices were the result of learned or innate associations, the researchers say.