New research has challenged the theory that people with autism lack empathy because of testosterone overload.
Researchers at the University of Pennsylvania found no connection between testosterone and empathy in a study of 643 men.
Gideon Nave, whose research found no connection between testosterone and empathy
They gave the men testosterone gel or a placebo, which is an inactive treatment, for comparison.
Questionnaires and empathy tests
The men then completed questionnaires and empathy tests.
Gideon Nave, an assistant professor of marketing at the university, led the study.
He said testosterone was the primary suspect in autism because the condition is much more common in boys.
Research suggests that three boys are diagnosed for every girl.
It led Professor Simon Baron-Cohen, of Cambridge University, to come up with his ‘extreme male brain’ theory of autism in 1997.
Systemising thinking style
This suggests autism is an exaggeration of ‘male’ tendencies toward a systemising thinking style, rather than one that is empathetic.
After giving participants the testosterone gel, Nave’s study showed them a photograph of an actor’s eyes.
They had to choose the emotional state that best described the expression.
While the gel increased testosterone, it did not affect performance on the empathy test.
Test on finger length
As well as studying empathy and testosterone, Nave also looked at another theory of autism. This was that the ratio of the second, or index finger, to the fourth is a biological marker for the condition.
It has been suggested a shorter second finger compared to the fourth indicates a more typically masculine brain.
In Nave’s study, researchers measured the participants’ second and fourth fingers. They found no relationship between empathy and the ratio of the second finger to the fourth.
Inconclusive
Despite the findings, Nave said the testosterone research does not show that the hormone plays no part in autism. He said: “The absence of evidence is not evidence of absence.”
Related:
- Study supports ‘male brain’ theory
- Transgender, non-binary linked to autism
- Autism link to fast growth in young boys
- Article about testosterone supplements
Published: 11 October 2019
