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. "Our hormonal reactions while
competing are part of how we evolved as a cooperative species."
How the study was done
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
"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 US National Library of Medicine to find out more about testosterone.