http://www.guardian.co.uk/commentisfree/2009/jan/14/autism-genetics-ethics

Newton and Einstein may have been autistic. But is their genius an argument against a screening test?Comments (86)

o Marcel Berlins o The Guardian, Wednesday 14 January 2009 o Article history

The prospect of a screening test on a pregnant woman predicting her child's autism is not far away, and Professor Simon Baron-Cohen, leader of the Cambridge University research team that developed the test, has called for an ethical debate on its desirability. My first reaction was puzzlement. Why a debate? We have had the test for Down's syndrome for many years. It seems to be generally accepted without controversy. No expectant mothers are obliged to have it, and many, even those at some risk because of their age, choose not to. Those that do take it have the choice, if it proves positive for Down's, between terminating the pregnancy or bearing the child. It is, of course, an agonising decision, but I'm not sure it raises special ethical issues.

Why should the autism test be treated differently? It is a different kind of condition, says Professor Baron-Cohen, often linked with talent. "What would we lose if children with autistic spectrum disorder were eliminated from the population?" It is a philosophical question, which stakes the claim of society to be involved in the debate, and not just the parents of the unborn child.

I don't normally like to use the slippery-slope argument, but it is apposite for issues arising from the bewildering speed of medical advances. Screening for Down's syndrome has become commonplace; a test for autism is imminent. There is no doubt that more and more tests will be found for more and more conditions, many of them far less life-threatening or seriously affecting quality of life than the ones we now give priority to. Where would we stop in offering pregnant women tests?

Or are we prepared to accept, or even welcome, a less diverse society that has rid itself of autistic children and, in time, of sufferers from other conditions difficult to cope with by the sufferer, his or her immediate entourage, or the medical profession? It's a sustainable argument that losing the tiny proportion of the population made up of autistic children will not have much effect on diversity; but the slippery slope results in many other potentially sick children not being born.

What I can not accept is the argument put forward on behalf of autism alone, and no other condition - that among those autistic children not born, because their mothers had the test and decided to terminate, there might be brilliant autistic savants who would make an important contribution to society. It is being asserted - I have yet to see any supporting evidence - that Albert Einstein and Isaac Newton were autistic; their mothers, in modern circumstances, might not have had them. The logical corollary of that approach is to refuse to offer the test to all pregnant women, just in case they were in danger of bearing an autistic child who would be among the exceptionally gifted 1% or 2%.

If we take up Baron-Cohen's call for a debate, we will have to decide between three elements: the autistic person's predicted quality of life (though the test may not be that precise); the feelings of the parents who may suffer far more than their child; and the view of society as to its diminished diversity if we continue to prevent the birth of the imperfect. The last should be the least listened to.

Disorder linked to high levels of testosterone in wombPrenatal screening tests could follow ground-breaking research into 235 children

Sarah Boseley

The Guardian, Monday 12 January 2009

Article history

A prenatal screening test for autism comes closer today as new research is published that links high levels of the male hormone testosterone in the womb of pregnant women to autistic traits in their children.

The ground-breaking study, published in the British Journal of Psychology by some of Britain's leading autism researchers, was prompted by the fact that autism is four times more common in boys than in girls. It is linked with other traits that are found more commonly in boys, such as left-handedness.

For more than eight years, a team at Cambridge University's autism research centre has been observing and testing the development of a group of 235 children whose mothers had an amniocentesis during pregnancy. The procedure involves drawing off fluid surrounding the baby in the womb using a fine needle and is offered by hospitals to pregnant women over 35 or 37 to test for Down's syndrome. The age and circumstances of the women have been taken into account in the research.

Dr Bonnie Auyeung, Professor Simon Baron-Cohen and colleagues, who publish their findings today, say they have consistently found a link between higher testosterone levels in the womb and autistic traits, such as a lack of sociability and verbal skills, in the children.

These are not autistic children, but many of us have traits that are more pronounced in those who have a medical diagnosis. Autism has been described as a consequence of an extreme male brain. Those affected do not empathise easily with other people (as girls tend to do more readily than boys). They cannot guess what other people are thinking or feeling. They have a much stronger drive towards analysis and constructing systems and can have a great ability to focus on something that absorbs them. People with autism include some brilliant, albeit eccentric and reclusive, mathematicians and musicians, as well as children who are never able to communicate and may end up in an institution.

In the early years of the study, the scientists could not measure autistic traits in the children, but they noticed some very early indicators. Male babies with higher testosterone levels were less likely to make eye contact at 12 months, their vocabulary was more limited between 12 months and 18 months, and at the age of four they were less sociable and had narrower interests.

Today's paper is a significant step forward because the children, now between eight and 10, are old enough to be psychologically assessed using two separate autism

rating tests. Scientists found a clear link, in both tests, between higher testosterone levels when the child was in the womb and autistic traits.

The study highlights for the first time the association between foetal testosterone and autistic traits, and indicates that foetal testosterone not only masculinises the body, it masculinises the mind and therefore the brain, said Baron-Cohen.

The children will continue to be followed for some years, but Baron-Cohen and his team have at the same time expanded their research to look at the relationship between testosterone levels in the womb and children with a diagnosis of autism. They have turned to Denmark, where a biobank has been freezing and storing many thousands of samples of amniotic fluid from pregnant women since 1990. A new, collaborative study, which will include autistic children, will be published this year.

The work opens the way for a screening test for pregnant women, which could potentially involve amniocentesis to draw off fluid from the womb to measure testosterone levels.

The work is published on the day the General Medical Council hearing into Dr Andrew Wakefield and colleagues at the Royal Free hospital resumes. The three doctors face allegations of serious professional misconduct over their study, published in the Lancet journal in 1998, which suggested a link between autism and MMR vaccination.

Their paper came at a time of intense anxiety over soaring autism levels, which doctors have ascribed partly to better diagnosis but have not completely explained. More than half a million people are diagnosed with an autistic spectrum disorder, including Asperger's syndrome, in Britain. One of the reasons it sparked such a furore is that parents with an autistic child have no idea what has caused the condition and are left in a state of bewilderment and worry, wondering if they themselves could somehow be responsible. Diagnosis is usually delayed and often followed the MMR vaccinations, given at around 13 months and three to four years.

A prenatal test would have the advantage of giving parents advance warning, so that they would be able to do everything possible to help their child from birth.

Even if a testosterone test is not developed (scientists may still find that it is not completely reliable), genetic screening will one day be on the cards. Scientists know that autism is partly genetic, because it runs in families, although environmental factors must play a part because there have been occasions where one identical twin was autistic and the other was not. More than 100 genes have been associated with autism, but it is not yet clear which are most important.

In numbers: Autism facts

• Autism is a complex developmental disability involving a biological abnormality in the functioning of the brain. It is not a learning disability or a mental health problem, although people with autism may also be affected by those conditions.

• The first detailed description of a child with autism was written in 1799 by the French doctor Jean-Marc Gaspard Itard in his account of the "wild boy of Aveyron".

• People with autism who have an extraordinary talent are known as "autistic savants". They are extremely rare, with at most one or two in 200 people with an autistic spectrum disorder thought to be savants.

• It is likely that more than half of those with an autistic spectrum disorder have an average to high IQ.

• Asperger's syndrome is a form of autism that affects how a person makes sense of the world, processes information and relates to other people. They may like a fixed daily routine because the world can seem confusing and uncomfortable. People with Asperger's are less affected by the syndrome and usually able to lead a normal life. David Batty

A prenatal test for autism would deprive the world of future geniusesAs a new book speculates that 'Britain's Einstein' was autistic, an autism expert warns that a prenatal test

for the condition would prevent brilliant scientists like Paul Dirac from ever being born

Comments (36)

Paul Dirac – a pioneer of quantum mechanics – displayed some of the classic signs of autism. Photograph: AIP Emilio Segrè Visual Archives

A new book on the greatest British physicist since Newton speculates that both his profound mathematical abilites and his extreme social awkwardness stemmed from undiagnosed autism.

The claims – from a biography of Paul Dirac by Graham Farmelo, The Strangest Man – tie in with an article on the BBC website from leading autism researcher Prof Simon Baron-Cohen. Baron-Cohen says we need a public debate about the prenatal diagnosis of autism. Although such a test is not yet available, it soon could be.

Baron-Cohen points out that the use of embryo selection during IVF to reject babies with autism genes might have the effect of preventing some individuals with brilliant mathematical abilities from being born.

More on Baron-Cohen's argument later, but first, Farmelo's book presents a highly detailed picture of a brilliant but profoundly odd man with an extremely troubled relationship with his parents. Given Dirac's contribution to science, Farmelo argues that he is shockingly under-appreciated and largely unknown in the UK, particularly in his home town of Bristol.

Dirac was one of the pioneers of quantum mechanics and quantum electrodynamics. For example, in 1930 he predicted that the electron has an equivalent anti-particle, the

positron – a notion that was greeted with scepticism and derision by some physicists at the time but was proved correct in experiments two years later.

He is the youngest theoretical physicist ever to win a Nobel Prize, and a year earlier in 1932 he was made Lucasian Professor of Mathematics at Cambridge. At 29 he was a few months older than Sir Isaac Newton when he took up the same position in 1669. Its current holder is Prof Stephen Hawking.

The physicist Freeman Dyson summed up Dirac's effortless brilliance thus:

His great discoveries were like exquisitely carved marble statues falling out of the sky one after another. He seemed to be able to conjure laws of nature from pure thought.

Perhaps not surprisingly, Dirac was also an extemely unconventional person (Farmelo's title is a quotation from Dirac's contemporary Niels Bohr). Even Einstein found him peculiar. "I have trouble with Dirac," he wrote to a friend. "This balancing on the dizzying path between genius and madness is awful."

Dirac was prone to very long silences and was famous for his apparently emotionless responses to events. He also often took a very literal interpretation of statements by other people. All are characteristics of autism.

When Farmelo spoke to Baron-Cohen about the condition he said he was struck by two things. First, that autistic men often have foreign wives, "perhaps because the women were more tolerant of unusual behaviour in foreign men than in men from their own culture." Dirac was married to a Hungarian woman for 50 years.

Baron-Cohen also said that autistic people are often extremely loyal. "When they believe that a friend has suffered an injustice, they are often so indignant that they will disrupt or abandon their almost invariable daily routines to rectify it," wrote Farmelo. Dirac demonstrated great loyalty to his friends the physicists Pyotr Kapitsa and Werner Heisenberg. There are also signs that Paul's father Charles was autistic and there was a history of depression and suicide in the Dirac family

Whatever the difficulties in diagnosing autism in a man who died in 1984, Baron-Cohen's argument is that preventing cases of the condition by screening the genes for autism out of the population could stop brilliant individuals such as Dirac ever being born.

Research is not yet at the stage where autism can be detected prenatally using a biological test, but this may not be far off ... If it was used to 'prevent' autism, with doctors advising mothers to consider termination of the pregnancy if their baby tested 'positive', what else would be lost in reducing the number of children born with autism?

Would we also reduce the number of future great mathematicians, for example? Or if this test led to some kind of prenatal treatment, such as the use of drugs to block the effect of testosterone which is already medically possible, would this be desirable?

Caution is needed before scientists embrace prenatal testing so that we do not inadvertently repeat the history of eugenics or inadvertently 'cure' not just autism but the associated talents that are not in need of treatment.

If a prenatal test for autism becomes available, should medical science be used to 'cure' the condition?

http://news.bbc.co.uk/2/hi/health/7736196.stm

Autism test 'could hit maths skills'

VIEWPOINTProfessor Simon Baron-Cohen Director, Autism Research Centre, Cambridge University

The prospect of a prenatal test

for autism, allowing couples to

choose whether to have a baby

with the condition, is coming

closer. And with it also comes

the possibility of a prenatal

drug treatment being

developed.

But in this week's Scrubbing Up, leading autism expert

Professor Simon Baron-Cohen warns caution is needed to

ensure associated talents, like numerical abilities, are not

lost if the test or a "cure" become available.

Males, maths and autism. On the face of it, these three things

don't appear to be linked. And yet they are.

Males are much more likely to apply to university to study maths, for

example.

In 2007, three quarters of applicants to read maths at Cambridge

were male, as were 90% of

applicants for the computer

sciences degree.

Cambridge is not unique in this

way. So why are males so

attracted to studying maths?

And why, in over 100 years of the existence of the Fields Medal,

maths' Nobel Prize, have none of the winners have ever been a

woman?

Similarly, people with autism are much more likely to be male.

Among those with classic autism, which includes a developmental

delay in language and a risk of learning difficulties, males outnumber

females by four to one.

And among those with Asperger Syndrome, males outnumber

females by nine to one.

People with the condition talk at a normal age and have at least an

average IQ, but share the social and communication difficulties of

those with classic autism, as well as the narrow - even obsessive -

An ability to understand numbers could be in DNA

Research is not yet at the

stage where autism can be

detected prenatally

Read your comments

interests and love of repetition.

'Male brains'

It seems as you move to the extremes of mathematical excellence,

autism becomes more common.

The search to understand why led scientists to genetics. Fathers and

grandfathers of children with

autism are more likely to work in

the field of engineering, a field

that needs good attention to detail

and a good understanding of

systems, just like mathematics.

Siblings of mathematicians also

have a higher risk of autism,

suggesting the link between maths

and autism is genetically

mediated. And parents of children with autism show male-typical

brain function in tests.

But genetics may not be the only explanation.

Research published this year showed a link between higher levels of

the male hormone testosterone in the amniotic fluid surrounding a

foetus and autistic traits when the child was eight.

And animal studies have shown

foetal testosterone levels

influence brain development,

masculinising it.

'Wise to think ahead'

Research is not yet at the stage

where autism can be detected

prenatally using a biological test,

but this may not be far off.

Such a test will need to prove itself clinically in terms of whether it is

highly specific (in detecting just autism).

But assuming such a test is developed, we would be wise to think

ahead as to how such a test would be used.

If it was used to 'prevent' autism, with doctors advising mothers to

consider termination of the pregnancy if their baby tested 'positive',

what else would be lost in reducing the number of children born with

autism?

Autistic traits have been linked to levels of the male hormone

FROM THE TODAY PROGRAMME

More from Today programme

Would we also reduce the number

of future great mathematicians,

for example?

Or if this test led to some kind of

prenatal treatment, such as the

use of drugs to block the effect of

testosterone which is already

medically possible, would this be

desirable?

If reducing the testosterone in a

foetus helped that baby's future

social development, we would all

be delighted.

But what if such a treatment

reduced that baby's future ability

to attend to details, and to understand systematic information like

maths?

Caution is needed before scientists embrace prenatal testing so that

we do not inadvertently repeat the history of eugenics or

inadvertently 'cure' not just autism but the associated talents that

are not in need of treatment.

SCRUBBING UP

The BBC News website is launching the

"Scrubbing Up" weekly column, where

leading clinicians and experts give their

perspectives on issues in health

Each week, you will be able to have

your say

I don't want to be 'cured' of autism, thanksDiscussion of prenatal testing hasn't included the people it plans to eliminate: society disables us more

than autism ever could

Comments (108)

o Anya Ustaszewski

o guardian.co.uk, Wednesday 14 January 2009 10.00 GMT

o Article history

I am not a savant or genius. I'm no good at maths or science, so I don't meet the criteria of the special gifts that might be lost if prenatal testing enabled parents to terminate foetuses deemed likely to develop autism. But I find it disturbing that no one yet seems to have seen fit to seek the opinion of individuals on the autistic spectrum.

As someone on that spectrum, I strongly oppose any kind of "cure" for autism; I also oppose prenatal testing and the eugenic elimination of autistics, as well as any research that could lead to these outcomes.

The autistic rights movement, which is allied to the wider disability rights movement, believes that people on the autistic spectrum are disabled more by society than by their autism. Like many members of this movement, I consider autism to be a part of natural human variation that should be accepted and respected, as with any other human difference.

Sadly, autism is often portrayed as a tragedy for both individuals on the spectrum (who are often said to be "suffering" from autism) and also their families. Interestingly, the organisations and individuals who disseminate and promote this image tend to be celebrity-seeking professionals who are seeking a lucrative "cure" for autism, or families who due to inadequate support and access provision see autism as the enemy, the cause of all their problems and something that should be minimised or eliminated.

Far more time and attention is given to parent-led organisations (in particular the National Autistic Society) and very little to user-led groups. The autistic rights movement is almost completely ignored.

Professor Simon Baron-Cohen wrote in a recent article:

Caution is needed before scientists embrace prenatal testing so that we do not inadvertently repeat the history of eugenics or inadvertently 'cure' not just autism but the associated talents that are not in need of treatment.

So my autism should be "cured", but the bits that society thinks it can find a use for should be kept? I find this incredibly insulting. My autism is part of who I am. It is not something "extra" that can be taken away from me to suit the agenda of an intolerant society. My abilities, challenges and perception of the world all go hand in hand. If I were to be "cured" of my autism, the person that I am would cease to exist.

To be frank, it makes me quite angry that little has been done to address the challenges autistics face. The world can be a frightening, painful, distressing and confusing place if you are autistic. There are, however, adaptations that can be made to the built environment, to ways of communicating and to society's attitudes that can go quite some way to relieving these challenges.

Despite the Disability Discrimination Act, little has been done to help make society more accessible for autistics. Legislation is mainly aimed at people with mobility impairments and those who are visually impaired or hard of hearing. When it comes to the autistic spectrum, the DDA is only of very limited use.

There are many things that can and should be done: they include changes to legislation to ensure that buildings are "autism friendly" such as a legal requirement for low arousal design, changes to noise legislation to reduce the sensory overload that is often experienced by autistics, especially those with hypersensitive hearing. Less visual clutter, better anti-discrimination laws and a legal right to assistive technology and communication devices would also help us.

The government has done little to improve access for autistics, or to change negative attitudes towards us. Instead, officials, professionals and parents alike are ready to consider eliminating us from existence.

What kind of a message does this send? Conform to neuro-typicality or we will eugenically wipe you out?

Autistics have not been listened to or given a proper chance to be accepted, understood and to thrive. Let's face it, it's much easier (and probably cheaper) to get rid of us than to support, help and (dare I say it) embrace us. So I think it imperative that individuals on the autistic spectrum are involved at all levels in the debate on pre-natal testing.

This should include people at various points on the spectrum, from "high functioning" to so-called "low functioning" autistics such as Amanda Baggs, who also supports the autistic rights movement.

In his excellent and moving essay Don't Mourn for Us, Jim Sinclair writes:

When parents say, 'I wish my child did not have autism', what they're really saying is, 'I wish the autistic child I have did not exist, and I had a different (non-autistic) child instead'.

This is what we hear when you pray for a cure. This is what we know, when you tell us of your fondest hopes and dreams for us: that your greatest wish is that one day we will cease to be, and strangers you can love will move in behind our faces.

Rather than pursuing a "cure", or subjecting autistics to "therapies" whose goal is to make them appear and act as neuro-typical as possible, the government professionals and parents should devote time, effort and funds towards supporting autistic individuals in developing strategies to manage the difficulties they face, to improve their skills and to make progress and fulfil their true potential.

It is also important to work towards curing the sometimes-distressing co-morbidities of autistic spectrum differences, such as intestinal disorders and epilepsy.

Most of all, society's attitude towards autism needs to change. Our communication style and any non-harmful autistic behaviours should be respected and accommodated. The physical environment should be adapted to be more accessible in order to allow us realistic opportunities for inclusion, and to enable us to be as independent as we can.

Listen to us. Get to know us. Respect us. Include us. Don't put all the onus on us to fit in to your world – meet us half way. And most of all, don't eliminate us just because we're different.

http://www.admin.cam.ac.uk/news/dp/2009011302

Research links testosterone levels to autistic traits13 January 2009

Research at Cambridge University’s Autism Research Centre (ARC) has found that exposure to high levels of testosterone in the womb is related to the development of autistic traits.

The findings, published in yesterday's British Journal of Psychology (January 12), show that levels of testosterone in amniotic fluid were linked to children's autistic traits up to ten years later.

Dr Bonnie Auyeung, Professor Simon Baron-Cohen and their colleagues at the ARC measured the levels of foetal testosterone in the amniotic fluid of 235 women who underwent amniocentesis (a test of the amniotic fluid to determine genetic defects in the foetal DNA) during pregnancy. Years later these mothers completed questionnaires that measured their child's autistic traits. By this time, the 118 boys and 117 girls were aged between 6 and 10.

High levels of foetal testosterone were found to be associated with high scores on two separate measures of autistic traits (the Child Autism Spectrum Quotient (AQ-Child) and the Childhood Autistic Spectrum Test (CAST)) for both boys and girls. High scores on these measures of autistic traits reflected poorer social skills and imagination but good attention to, and memory for detail.

Professor Baron-Cohen said: "The study highlights for the first time the association between foetal testosterone and autistic traits. We all have some autistic traits - these are a spectrum or a dimension of individual differences, like height."

He added: "It is a shame that this research was inaccurately reported in some sections of the media that suggested the study demonstrated that elevated foetal testosterone is associated with a clinical diagnosis of autism or Asperger Syndrome. Our study has not yet shown that. To do that would need a sample size of thousands, not hundreds. Our ongoing collaboration with the Biobank in Denmark will enable us to test that link in the future.

"Reports also linked this research with prenatal screening for autism that was not the objective of this study. This study was not a screening study and was conducted purely to understand the basic neurobiological mechanisms underlying individual differences in autistic traits."

Dr Auyeung commented: "This research goes further than previous studies which have found that higher levels of foetal testosterone are associated with less eye contact in the child's first year, slower language development by their second birthday, more peer difficulties at four years old and more difficulties with empathy by the time they're six. This new study also links higher foetal testosterone to autistic traits such as excellent attention to detail, and a love of repetition, as well as social and communication difficulties".

This unique longitudinal project was funded by the Medical Research Council and the Boston-based Nancy Lurie Marks Family Foundation. The published paper as a pdf is available from the Autism Research Centre's website, follow the link on the right.

http://www.nature.com/news/2009/090113/full/news.2009.21.html

What is the link between autism and testosterone?Controversial theory of autism makes headlines, but leaves scientific community unconvinced.

Asher Mullard

Talk of diagnosing autism in the womb, say researchers.Alamy

Children who are exposed to high levels of testosterone in the womb show similar results in psychological tests to people with autism. The

findings provide support for a contentious theory of the condition's cause, researchers say.

But while the media anticipate autism screening, researchers in the field urge caution, both about the importance of the findings and of the

case for screening.

At least four times as many males as females develop autistic disorders. For Asperger's syndrome, the ratio is nine to one1.

Simon Baron-Cohen, a developmental psychologist at the Autism Research Centre at the University of Cambridge, UK, believes that this is

because traits associated with autism — such as a difficulty in empathizing and enhanced abilities to analyse, explore and extract the rules

that underlie complex systems — are extreme manifestations of normal male behaviour.

Baron-Cohen and his colleagues now report in the British Journal of Psychology that children who had been exposed to high concentrations of

testosterone as a fetus are more likely to exhibit autistic traits1. And as high fetal testosterone concentrations have been associated with

some aspects of male cognitive ability, they say that their findings provide support for the 'extreme male brain' theory of autism.

But two commentaries23 published in the same issue of the journal show that not everyone agrees about the value of this study, or even on

the theory in general.

Testing times

For more than a decade, Baron-Cohen's team has looked at how fetal testosterone concentrations — measured in pregnant women who had

the amniotic fluid that surrounded their fetuses tested for medical purposes — correlate with development in 235 children without autism.

The researchers had already found that those children who were exposed to high concentrations of fetal testosterone exhibited some

characteristics of adults with autistic disorders, such as making less eye contact, developing fewer interests and having poorer quality

relationships1.

Now that the children are on average nine years old, Baron-Cohen and his colleagues have used two questionnaires to look for subtler

aspects of autism. The questionnaires asked the mothers about factors such as their children's attention to detail (which is usually high in

people with autistic disorders) and ability to know what others are thinking (usually low in people with autism).

Again, they found that the higher the testosterone concentration in the womb, the more similar the results were to those seen in people with

autistic disorders.

A special brain?

Psychologist Kate Plaisted Grant, also from the University of Cambridge, calls the study "intriguing", but says that "it doesn't establish a link

between fetal testosterone and the cognitive profile of autism". For instance, she says, it does not show a correlation between testosterone

and visuospatial skills, in which patients with autism are usually very proficient.

She also isn't convinced that the findings support the underlying theory. "The broader scientific community hasn't accepted the idea of the

extreme male brain," she says. Fetal testosterone "may create a special brain, but it doesn't necessarily create a male brain".

Psychiatrist Laurent Mottron, from the University of Montreal in Canada, and an author of one of the commentaries, raises other concerns. In

particular, he says that just because males and people with autistic disorders score similarly in autism questionnaires, this does not mean

that autistic traits are the same as male traits. Rather, he argues, it just shows that the test cannot discriminate between maleness and

autism.

"For me, it's exactly the same as saying that two things that weigh the same are both made of the same stuff," he explains.

Media misinterpretation

Everyone does agree on one thing, however — that the British media has over interpreted the data.

"The Guardian [newspaper] is focusing on the issue of screening. The study is not about screening and it is not motivated by trying to develop

the screening test. It was motivated by trying to understand possible causal factors in autism," says Baron-Cohen.

And even if a biological marker for autism is found, many feel that the question of screening is a moral, rather than a scientific, question.

"Individuals with autism are remarkable individuals who have fantastic skills and who are a huge asset to our society," says Plaisted Grant.

"The thought that there would be genetic screening so that these individuals wouldn't be born, I find abhorrent."

References

1. Auyeung, B. et al. Br. J. Psychol 100, 1– 22 (2009).

2. Barbeau, E. B., Mendrek, A. & Mottron, L. Br. J. Psychol 100, 23–28 (2009).

3. Klin, A. Br. J. Psychol 100, 29– 32 (2009).

Comments

Reader comments are usually moderated after posting. If you find something offensive or inappropriate, you can speed this process by clicking 'Report this comment' (or, if that doesn't work for you, email redesign@nature.com). For more controversial topics, we reserve the right to moderate before comments are published.

Dr Kate Plaisted-Grant says that our 2009 study in the British J. Psychology has not established a link between foetal testosterone (FT) and the

cognitive profile of autism. However, this study did not set out to test that link, as it does NOT study children with autism. This is a common

misunderstanding. The study focuses on typically developing children. To test for a link between FT and autism per se would require a sample

size of thousands, not hundreds, as autism is only 1% of the population. We are pleased to see that she acknowledges that FT creates a 'special

brain', though she refrains from using the term 'male brain'. For us, this special brain is, as your journalist describes, one that has a stronger

drive to systemize but a weaker drive to empathize. Prof Laurent Mottron also makes a common error, namely, saying that males and people

with autism score the SAME on autism questionnaires. In fact, there are no studies that show this, but there are many that show that people

with autism show an extreme of the male score on autism questionnaires. And nor do male and autistic brains weigh the same, if we take

Mottron's comment literally. The average male brain weighs more than the average female brain, and the average autistic brain weighs even

more than the average male brain. The citations supporting the above statements can be found in Baron-Cohen, S, Knickmeyer, R, & Belmonte,

M (2005) Sex differences in the brain: implications for explaining autism. Science, 310, 819-823. The extreme male brain theory of autism

remains to be tested using MRI, and the FT theory of autism also remains to be tested in large enough samples. Finally, I too would oppose

prenatal screening for autism (which the Guardian (January 12th 2009) confused with our study) with a view to prevention or termination, on

moral grounds. Though if such a test existed (which it does not yet), parents are of course free to exercise their legal right to choose. Simon

Baron-Cohen, Cambridge