Showing posts with label Extreme Male Brain. Show all posts
Showing posts with label Extreme Male Brain. Show all posts

Wednesday 6 November 2013

Why Girls don’t get Mild Autism and Why Alpha Females may have Kids with Autism.

You may or may not have seen the 2006 comedy film Borat; it was critically acclaimed in the US, but took a bit of time to become a commercial hit.  It brought to public attention its writer, producer and leading man, Sacha Baron Cohen.
Ted, aged 13 and very neurotypical, is a fan of Borat.
In the autism research community, Sacha’s brother Simon is equally well known.  He is the Director of the Cambridge University's Autism Research Centre and a Fellow of Trinity College.

All very interesting,  Ted’s Grandfather also went to Trinity College Cambridge.  Ted’s brother, Monty aged 10 with ASD, has yet to produce a movie, but he has helped to produce an autism blog.    
As you may have noted on this blog, I am rather disappointed with the autism research coming out of the United Kingdom.  90% of the good stuff is from the US.

The extreme male brain theory of autism
One of the well-known autism theories is from Simon Baron-Cohen, it is called:-

Simon has been developing his theory that something called “assortative mating” may be at least partly to blame for the spectacular rise in autism diagnoses.
The theory states that when people with strongly “systemising” personalities – the sort of people who become engineers, doctors and computer experts – marry each other and produce children, the effects of this kind of “male brain” are genetically magnified, increasing the chances of producing an autistic child – a child with what Simon suspects is an “extreme male brain”.
Strong “systemisers” are often slightly obsessive, perfectionist and make great scientists and are often extremely talented at music. But they sometimes have difficulties socially interacting with other people – a combination of traits that can blend into the milder end of the autism spectrum.
Some of the sharpest increases in autism diagnoses have been found in Silicon Valley, home to perhaps the largest population of successful systemisers on Earth. Tens of thousands of technicians, engineers and programmers work in the computer industry;  inevitably, many of these people marry each other.
Until relatively recently, being exceptionally bright was not much use to you if you were female. The opportunities for a woman to earn her living through brainpower alone were extremely limited. You could be a teacher, or perhaps, if you were lucky, a doctor.
Going to university was difficult and expensive; most did not even allow girls to study. There were certainly few opportunities for careers in engineering or the sciences.
Brainy women were not even seen as particularly desirable partners. Clever or rich men chose brides on the grounds of looks, “breeding” or both. If she did have a job, many employers would automatically fire a woman the moment she turned up with an engagement ring. So many clever, “systemising” women simply did not marry, or married late and probably had fewer children when they did.
Now everything has changed. Not only have the legal and social barriers to women entering the workplace as equals been largely dismantled, we also have the phenomenon of the desirable “alpha female”.
Fifty years ago many men were scared of smart women. Now, increasingly, alpha males want someone their equal. Fifty years ago, male airline pilots typically married stewardesses; now they marry other pilots. Doctors used to marry nurses; now they marry other doctors.
But the phenomenon of like marrying like may be having completely unexpected consequences.  

The Peter Theory of the Neuroprotective Effect of Female Hormones in Autism
Unlike Simon, I do not have a brother who is a movie star, with a Golden Globe; my brother designs car engines, but his engine did win the International Engine of the Year Award in 2013.

I always wondered why it was that kids with autism are mainly boys and when you do meet an autistic girl, she tends to be at the moderate to severely affected end of the spectrum.  Then there is Simon’s observation that alpha females produce disproportionately more kids with ASD.  Then there is the question as to why Anglo-Saxon countries (Australia, Canada, New Zealand, the United Kingdom, and the United States) but particularly the US, have a higher incidence of autism than the rest of the world; is it really just over-diagnosis?
The hormones Estrogen and Progesterone are known to be highly neuroprotective.  Testosterone may also have some neuroprotective properties, but they seem to be of a lesser extent.   While Estrogen and Progesterone are known as female hormones and Testosterone is the male hormone, both sexes have all three hormones, just in different amounts.  We learnt in an earlier post that the stress hormone Cortisol is neurotoxic.
Imagine an experiment:

On the left, you have a stressed alpha female
 (cortisol↑ testosterone↑ estrogen↓  progesterone↓)
with a male fetus (testosterone↑ estrogen↓ progesterone↓)

On the right, you have a calm beta female
 (cortisol↓ testosterone↓ estrogen↑  progesterone↑)
with a female fetus (testosterone↓  estrogen↑  progesterone↑)  
Then both subjects experience a sharp oxidative shock from the environment.

The beta female, with the female fetus, have a major neuroprotective advantage . They can generally weather the storm; only in severe cases is the neuroprotection overcome and the result is a severely autistic girl. 

The alpha female, with the male fetus, cannot weather even a moderate shock and the result is a mildly affected autistic boy.  The more rare severe shocks, produce severe autism.

The kind of insults that produce damaging oxidative shocks have been well documented by researchers like Abha Chauhan. 
This latest Peter Theory is hopefully flawed, after all, what do you learn about biology in Engineering School and Business School?  There should be much more talented people out there.  If it was correct, it would open up avenues in very simple preventative medicine.

P.S.   I am using a little dramatic license; Simon is actually Borat's cousin, not strictly his brother.