Testosterone aggression link disputed

Research conducted by Swiss scientists challenges the common belief that testosterone causes aggression in humans.

The hormone instead encourages status-seeking behaviour, scientists at Zurich University and the University of London believe. The findings were reported in the journal Nature on Tuesday.

The study involving 120 women also showed that conventional wisdom about the effects of the sexual hormone is so strong that people behave more aggressively if believe they have been given a dose even if they have not, the journal said.

“It is a folk hypothesis that testosterone causes aggression,” said Zurich University experimental economist Ernst Fehr. “But human society is more complex than this.”

Testosterone is a steroid hormone secreted by the male testes and to a lesser extent by the female ovaries that affects brain development and sexual behaviour. Research has found that it leads to a substantial increase in aggressive behaviour in rodents.

This wisdom has even reached the courtrooms because steroid-induced rage has been used as legitimate legal defence in the United States, it says.

But the research shows that the steroid does not have the same effect in humans as it does in animals, it says.

“The preconception that testosterone only causes aggressive or egoistic behaviour in humans is thus clearly refuted,” said Zurich University neuroscientist Christoph Eisenegger

swissinfo.ch and agencies