With testosterone, it’s my way or the highway
01 February 2012, 17:58
Testosterone can skew one's judgement, creating the impression that
decisions are best taken alone even in situations that call for
collaboration, according to a study.
In a clever set of experiments, scientists led by Nicholas Wright at
the University of London showed that women given a dose of testosterone become less inclined to act in concert even when it was clearly in their interest to do so.
Finding the right balance between working together and going solo – and
knowing when to do one or the other – is an essential life skill.
In some circumstances, joining forces with others is the best way to
achieve a desired result: that's why lions and hyenas hunt in packs, and
why humans cooperate on the playing field, in the laboratory, or in
Testosterone boosts risk-taking
Sometimes, however, decisive individual action is needed to break free of group-think, or to come out ahead of the game.
To a significant extent, our ability to navigate between these two
extremes is acquired through learning and experience, but some of these
impulses are hardwired too.
Earlier research, for example, on the biological underpinnings of group
decision making revealed that a naturally-occurring hormone, oxytocin, promotes the urge to work side-by-side.
At the same time, it was well established that testosterone boosted
risk-taking, anti-social behaviour and the kind of aggressiveness that
fuels contact sports and trading floors on Wall Street.
But whether the alpha male hormone par excellence – also present at
much lower levels in females – also makes individuals shun cooperation
and become more egocentric was not known.
To find out, Wright and his colleagues carried out a series of tests
over two days spaced a week apart, with 17 pairs of women volunteers who
did not know each other.
On one of the two days, both volunteers in each pair were given a
testosterone supplement, while on the other day they ingested a
The researchers chose females because in men an additional dose has the
effect of suppressing production of the hormone by the body.
The right answers
During the experiment, both women in each pairing sat in the same room but in front of separate computer screens.
The women were shown the same two images, and asked to pick the one in
which a hard-to-discern high-contrast pattern appeared. If their
individual choices agreed, the exercise ended there.
But if they diverged, the women were told to consult with each other and reach a joint decision.
Pairs of women who had taken the dummy pill were significantly more
successful in coming up with the right answer than those pairs who had
been given the hormone, the researchers found.
"The higher levels of testosterone were associated with individuals
behaving egocentrically and deciding in favour of their own selection
over their partner's," even when that choice was wrong, Wright said in a
"Too much testosterone can help blind us to other people's views," he
concluded. "This can be very significant when we are talking about a
dominant individual trying to assert his or her opinion in, say, a
The broader conclusion, he added, is that hormonal levels can disrupt our attempts to work together.
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