The search for understanding and answers regarding autism has sent scientists and medical professionals in dozens of different directions over the past 100 years. Everything from vaccines (debunked in various clinical studies) to lead poisoning have been blamed, but some research suggests prenatal testosterone levels might be to blame.
Simon Baron-Cohen, a professor of Developmental Psychopathology at the University of Cambridge, is the director of the university’s Autism Research Centre and has devoted much of his work to exploring the hormone testosterone.
Research has found that autism is four to five times more common in boys than girls, and an estimated 1 out of 54 boys and 1 in 252 girls are diagnosed with autism in the United States on average. Despite the controversy surrounding sex difference studies that address the idea of a masculine brain versus a feminine brain, Baron-Cohen has followed his hunch.
“What might males produce more of that could produce this connection? Males produce twice as much testosterone in the womb, and prenatal testosterone influences brain development. We tested fetal testosterone, and found higher levels predicted autistic traits in the child later, and also an interest in systems. So it’s prenatal testosterone, not gender, that’s associated with scientific talent.”
In the late 1990s, he began researching fetal testosterone (FT) through amniocentesis tests. This testing takes a sample of a mother’s amniotic fluid, which surrounds the baby in the uterus. Baron-Cohen then followed the children as they developed to see how FT impacted them as they grew up.
The fetus is producing his or her own testosterone, and it gets excreted into the amniotic fluid. The mother, as you pointed out, is also producing her own testosterone, and the understanding is that testosterone doesn’t cross the placenta … So, if you’re finding any testosterone in the amniotic fluid … it’s coming from the fetus.
In 2009, the study revealed that FT is negatively related with social and language development but positively correlated with attention to detail and a number of other autistic traits.
Now, because of Baron-Cohen’s findings, more research is being done into the connection between FT and and autistic traits, Asperger’s syndrome, and empathy. Working with Mike Lombardo, Baron-Cohen conducted the first human study of how FT influences grey matter in the brain, and he is currently working with the Danish National Biobank to examine FT and and autism development.
With more than 25 different genes impacting how much testosterone any of us produces, the understanding of how it affects development and growth are endless.
For more on Baron-Cohen’s take on the gender imbalance with autism and how testosterone might just be the key to understanding the disorder, Watch this video from Wired.
What is your opinion on the connection between testosterone and autism?