TUESDAY, May 28, 2013 (HealthDay News) -- After winning a team competition against strangers or rivals, men's testosterone levels increase. But when they're victorious against friends, their testosterone levels remain the same, according to a new study.
This response during group competition is rooted in evolution and related to how humans form coalitions or alliances in warfare, the researchers said.
"One interesting thing about humans is that we are the only animal that competes in teams," Mark Flinn, a professor of anthropology at the University of Missouri, said in a university news release. "Our hormonal reactions while competing are part of how we evolved as a cooperative species."
The study, published in the journal Human Nature, involved men of different ages who played dominoes or cricket on Dominica, a Caribbean island. Men who competed against a team of strangers and won had higher testosterone levels both during and after the competition. In contrast, men who competed against their friends did not have an increase in testosterone regardless of whether they won or lost.
Men who are watching a group competition could also experience a similar increase in their testosterone levels, the researchers said.
"For example, when [Missouri] plays the University of Kansas, males will probably have a huge increase of testosterone during the game and afterward if their team is victorious," Flinn said. "At the same time, we can create a coalition of fans while attending the game and bond together during the event."
"The fascinating thing about humans is that whether we are watching or playing the sport, we have the ability to put interactions among the whole team in our heads," he added. "That just shows how complex our social psychology is. For example, a hockey or basketball player can anticipate how his teammates are going to react when he passes to each one of them and predict the outcome. The ability for humans to be able to do that is pretty astonishing."
Go to the U.S. National Library of Medicine to find out more about testosterone.