Testosterone interferes with empathy

London: Scientists have discovered that male sex hormone testosterone influences the ability to empathise with others, a finding which they say could lead to new drugs and treatments for conditions like autism.

A team of British and Dutch scientists, who gave women a small dose of testosterone, found that it makes them less able to empathise with others.

The researchers said their findings add weight to the theory that the hormone is significant in the development of autism and could lead to new treatments for the condition, the BBC reported.

For their study, the team from University of Cambridge in UK and Utrecht University of The Netherlands recruited 16 women volunteers who were given a small dose of the men hormone.

It was found that the women were less able to judge the mood of facial expressions they were shown, an indication that suggests exposure to the hormone in the womb may be key.

Autism is a disorder which, to varying degrees, affects the ability of children and adults to communicate and interact socially.

While various genes linked to the condition have been found, the precise combination of genetics and other environmental factors which produce autism is still unclear.

The rate of autism is much higher among boys than it is among girls. Women, on average, have lower levels of the male sex hormone testosterone than men.

The researchers gave volunteers a dose of the hormone to see if this affected one of the key areas linked to autism -the ability to empathise.

In standard tests of "mind-reading", in which subjects look at pictures of faces and try to guess the mood of the person pictured, women tend to do better than men.

However, the testosterone dose caused a significant reduction in this "mind-reading" advantage amongst the women.

The findings, appeared in the journal PNAS, also hinted at the significance of testosterone exposure in the womb.

Professor Jack van Honk, one of the researchers, said: "We are excited by this finding because it suggests testosterone levels prenatally prime later testosterone effects on the mind."

Fellow researcher Prof Simon Baron-Cohen added: "This contributes to our knowledge of how small hormonal differences can have far-reaching effects on the mind."

However, Professor Uta Frith, an autism researcher at University College London, said the findings needed to be treated with caution.

"The testosterone theory is interesting, but it is still just one of many theories about the origins of autism," she said.

"I hope these results can be reproduced by other research teams, as the number of women involved are quite small.