# Simon Baron-Cohen

Sir Simon Philip Baron-Cohen (born 15 August 1958) is a British clinical psychologist and professor of developmental psychopathology at the University of Cambridge. He is the director of the university's Autism Research Centre and a Fellow of Trinity College.
In 1985, Baron-Cohen formulated the mindblindness theory of autism, the evidence for which he collated and published in 1995. In 1997, he formulated the prenatal sex steroid theory of autism, the key test of which was published in 2015. In 2003, he formulated the empathising-systemising (E-S) theory of autism and typical sex differences, the key test of which was published in 2018.
He has also made major contributions to research on autism prevalence and screening, autism genetics, autism neuroimaging, autism and vulnerability, autism intervention and synaesthesia. Baron-Cohen was knighted in the 2021 New Year Honours for services to people with autism. In 2023, he was awarded the Medical Research Council (MRC) Millennium Medal.

## Early life and education

Baron-Cohen was born into a middle-class Jewish family in London, the second son of Judith and Hyman Vivian Baron-Cohen.
He completed a BA in human sciences at New College, Oxford, and an MPhil in clinical psychology at the Institute of Psychiatry, King's College London. He received a PhD in psychology at University College London; his doctoral research was in collaboration with his supervisor Uta Frith.

## Career

Baron-Cohen is professor of developmental psychopathology at the University of Cambridge in the United Kingdom. He is the director of the university's Autism Research Centre and a Fellow of Trinity College.
He is a Fellow of the British Psychological Society (BPS), the British Academy, the Academy of Medical Sciences, and the Association for Psychological Science. He is a BPS Chartered Psychologist and a Senior Investigator at the National Institute for Health and Care Research (NIHR).
He serves as vice-president of the National Autistic Society (UK), and was the 2012 chairman of the National Institute for Health and Care Excellence (NICE) Guideline Development Group for adults with autism. He has served as vice-president and president of the International Society for Autism Research (INSAR). He was founding co-editor-in-chief of the journal Molecular Autism.
He was the chair of the Psychology Section of the British Academy. He is also a clinical psychologist who has created a diagnosis clinic in the UK for late autism diagnosis in adults.
Baron-Cohen gave the keynote lecture on the topic of Autism and Human Rights at the United Nations on World Autism Awareness Day in 2017.
In 2024, he was awarded an Honorary Fellowship to the Royal Society of Medicine for his contributions to the field of psychiatry.

## Research
### The mindblindness theory of autism

Baron-Cohen has worked in autism research for over 40 years, starting in 1982. In 1985, while he was member of the MRC Cognitive Development Unit (CDU) in London, he and his colleagues Uta Frith and Alan Leslie formulated the "theory of mind" (ToM) hypothesis, to explain the social-communication difficulties in autism. ToM (also known as "cognitive empathy") is the brain's partially innate mechanism for rapidly making sense of social behavior by effortlessly attributing mental states to others, enabling behavioral prediction and social communication skills. They confirmed this using the false belief test, showing that a typical four-year-old child can infer another person's belief that is different to their own, while autistic children on average are delayed in this ability.
Baron-Cohen's 1995 book, Mindblindness summarized his subsequent experiments in ToM and the disability in ToM in autism. He went on to show that autistic children are blind to the mentalistic significance of the eyes and show difficulties in advanced ToM, measured by the "reading the mind in the eyes test" (or "eyes test") that he designed. He conducted the first neuroimaging study of ToM in typical and autistic adults, and studied patients with acquired brain damage, demonstrating lesions in the orbito- and medial-prefrontal cortex and amygdala can impair ToM. He also reported the first evidence of atypical amygdala function in autism during ToM. In 2017, his team studied 80K genotyped individuals who took the eyes test. He found single nucleotide polymorphisms (SNPs) partly contribute to individual differences on this dimensional trait measure on which autistic people show difficulties. This was the evidence that cognitive empathy/ToM is partly heritable. The National Institutes of Health recommended Baron-Cohen's eyes test as a core measure that should be used as part of the Research Domain Criteria (RDOC) for assessing social cognition.

### Empathizing-systemizing (E-S) theory

In 1997, Baron-Cohen developed the empathizing-systemizing (E-S) theory. Empathizing includes both cognitive empathy (imagining what someone else is thinking or feeling) and affective empathy (responding with an appropriate emotion to what someone is thinking or feeling). Systemizing is the drive to analyse or construct rule-based systems to understand how things work. A system is defined as anything that follows if-and-then patterns or rules.
The E-S theory argues that typical females on average score higher on empathizing relative to systemizing (they are more likely to have a brain of type E), and typical males on average score higher on systemizing relative to empathizing (they are more likely to have a brain of type S). Autistic people are predicted to score as an extreme of the typical male (they are more likely to have a brain of type S or extreme type S). These predictions were confirmed in a 2018 online study of 600,000 non-autistic people and 36,000 autistic people. This also confirmed that autistic people on average are "hyper-systemizers".
Working with the personal genomics company 23andMe, Baron-Cohen's team studied 56K genotyped individuals who had taken the Systemizing Quotient. He and his colleagues found that the common genetic variants associated with systemizing overlapped with the common genetic variants associated with autism. He concluded that the genetics of autism not only includes genes associated with disability but also include genes associated with talent in pattern recognition and understanding how things work.

### Prenatal neuroendocrinology

Baron-Cohen's work in E-S theory led him to investigate whether higher levels of prenatal testosterone explain the increased rate of autism among males. His prenatal sex steroid theory of autism had preliminary support in 2009 in finding that prenatal testosterone was positively correlated with autistic traits in childhood and gained additional support in 2015 and 2019 in finding elevated prenatal androgens and estrogens in pregnancies that later were linked to a diagnosis of autism.
In his 2004 book Prenatal Testosterone in Mind (MIT Press), Baron-Cohen put forward the prenatal sex steroid theory of autism. He proposed this theory to understand why autism is more common in males. Using the Cambridge Child Development Project that he established in 1997, a longitudinal study studying children of 600 women who had undergone amniocentesis in pregnancy, he followed these children postnatally. This study demonstrated, for the first time in humans, how normative variation in amniotic prenatal testosterone levels correlates with individual differences in typical postnatal brain and behavioral development. His team discovered that in typical children, amount of eye contact, rate of vocabulary development, quality of social relationships, theory of mind performance, and scores on the empathy quotient are all inversely correlated with prenatal testosterone levels. In contrast, he found that scores on the embedded figures test (of attention to detail), on the systemizing quotient (SQ), measures of narrow interests, and number of autistic traits are positively correlated with prenatal testosterone levels. Within this study his team conducted the first human neuroimaging studies of brain grey matter regional volumes and brain activity associated with prenatal testosterone. Other clues for the theory came from Baron-Cohen's postnatal hormonal studies which found that autistic adults have elevated circulating androgens in serum and that the autistic brain in women is 'masculinized' in both grey and white matter brain volume. An independent animal model by Xu et al. (2015, Physiology and Behavior, 138, 13–20) showed that elevated prenatal testosterone during pregnancy leads to reduced social interest in the offspring.
Baron-Cohen's group also studied the rate of autism in offspring of mothers with polycystic ovary syndrome (PCOS), a medical condition caused by elevated prenatal testosterone. He found that in women with PCOS, the odds of having a child with autism are significantly increased. This has been replicated in three other countries (Sweden, Finland, and Israel) and is in line with the finding that mothers of autistic children themselves have elevated sex steroid hormones. But to really test the theory, Baron-Cohen needed a much larger sample than his Cambridge Child Development Project, since autism only occurs in 1% of the population. So, in 2015, he set up a collaboration with the Danish Biobank which has stored over 20 thousand amniotic fluid samples which he linked to later diagnosis of autism via the Danish Psychiatric Register. He tested the prenatal androgens and found that children later diagnosed as autistic were exposed to elevated levels of prenatal testosterone, and the Δ4 sex steroid precursors to prenatal testosterone. In 2019 he tested the same cohort's levels of exposure to prenatal estrogens and again found these were elevated in pregnancies that resulted in autism. These novel studies provide evidence of the role of prenatal hormones, interacting with genetic predisposition, in the cause of autism.

### Other contributions

In 2006, Baron-Cohen proposed the assortative mating theory which states that if individuals with a systemizing or "type S" brain type have a child, the child is more likely to be autistic. One piece of evidence for this theory came from his population study in Eindhoven, where autism rates are twice as high in that city which is an IT hub, compared to other Dutch cities. In addition, he found both mothers and fathers of autistic children score above average on tests of attention to detail, a prerequisite for strong systemizing.
In 2001, he developed the autism-spectrum quotient (AQ), a set of fifty questions that measures how many autistic traits a person has. This was one of the first measures to show that autistic traits run right through the general population and that autistic people on average simply score higher than non-autistic people. Baron-Cohen has replied to this by saying there are no questions in the AQ that ask about mathematical interest, and that the finding that AQ is associated with scientific and mathematical talent has been found in multiple studies, suggesting these may have shared mechanism such as strong systemizing. The AQ has subsequently been used in hundreds of studies including one study of half a million people, showing robust sex differences and higher scores in those who work in STEM. Multiple studies have also shown that both psychological and biological variables correlate with the number of autistic traits a person has.
Baron-Cohen also developed Mindreading, for use in special education. His team also developed The Transporters, an animation series aimed at teaching emotion recognition to preschool age autistic children, and conducted the first clinical trial of lego therapy in the UK, finding that autistic children improve in social skills following this.
He has also contributed to applied autism research. He found that autistic people are being failed by the criminal justice system, and have higher rates of suicidality, higher rates of postnatal depression, and higher rates of mental and physical health conditions.

### Reception

Spectrum News had described the work of Baron-Cohen on theory of mind as "a landmark study". The Lancet described him as "a man with extraordinary knowledge, but his passionate advocacy for a more tolerant, diverse society, where difference is respected and cultivated, reveals a very human side to his science".
Baron-Cohen's book, The Essential Difference was described by The Guardian as "compelling and inspiring" while his book, The Pattern Seekers was selected as the Editor's Choice by the New York Times. A book review published in Phenomenology and the Cognitive Sciences characterized The Essential Difference as "very disappointing". According to Time magazine, his views on systemizing traits had "earned him the ire of some parents of autistic children, who complain that he underestimates their families' suffering". Baron-Cohen has replied in an op-ed in Scientific American acknowledging the challenges families face. He has also commented that the huge body of scientific evidence supporting predictions from the mindblindness and E-S theories cannot be ignored.
Baron-Cohen and his book The Science of Evil were described by The New York Times "an award-winning psychologist" who had "unveiled a simple but persuasive hypothesis for a new way to think about evil."
Baron-Cohen's "empathizing-systemizing theory" was published in Science, and states that humans may be classified on the basis of their scores along two dimensions (empathizing and systemizing); and that females tend to score higher on the empathizing dimension and males tend to score higher on the systemizing dimension. Feminist scientists, including Cordelia Fine, neuroscientist Gina Rippon, and Lise Eliot have questioned his extreme male brain theory of autism. Baron-Cohen has defended the study of sex differences against their charges of neurosexism, clarifying that gender differences only apply to differences on average between groups of males and females, and agrees that it would be sexist and unacceptable to prejudge an individual based on their gender since a person's mind may not be typical of their gender. Multiple data sets have now confirmed the E-S and extreme male brain theories.
Time magazine has also criticized the assortative mating theory proposed by Baron-Cohen, claiming that it is largely speculative and based on anecdotal evidence. The theory claims that autism rates are increasing because "systemizers", individuals with more autistic traits, are more likely to marry each other and are more likely to have autistic offspring due to relatively recent societal changes. James McGrath has criticized the autism-spectrum quotient, writing that the score increases if one indicates interest in mathematics, and decreases if one indicates interest in literature or art. He claims that this leads to the false notion that most autistic people are strong in math.
Critics also argue that Baron-Cohen's focus on autistic people without intellectual or learning disability limits how far his findings can be generalised. Baron-Cohen has acknowledged that a disproportionate amount of autism research globally is conducted with autistic people without learning (intellectual) disabilities and has called for more research with autistic people who have learning disabilities, to ensure that autism research serves the whole autism community. But he challenges this criticism in pointing out that even among those with learning disability, strong systemizing is observed.
The theory of mind deficit hypothesis, especially the universal core deficit version, has faced many criticisms from some people in the autism community and from researchers. Baron-Cohen has commented that many studies have replicated the findings with group-level on-average differences, despite the heterogeneity of autism in terms of empathy and ToM, including multiple studies conducted by Simon Baron-Cohen in recent years, which found that around 40–60% of autistic people have impaired ToM and empathy, whereas the other 40–60% of autistic people are unimpaired or above average in ToM and empathy.
The mindblindness hypothesis has faced criticism from some people in the autism community who have argued that non-autistic people are as blind to the mental states of autistic people as autistic people are to those of non-autistic people. This is referred to as the “double-empathy” problem. There is also criticism of Baron-Cohen's concept of theory of mind on the grounds that it implies that autistic people as not fully human. Regarding the first criticism, Baron-Cohen has agreed that the “double-empathy” problem is an important contribution to this field. Regarding the second criticism, Baron-Cohen has replied that autistic people are fully human and that theory of mind simply exists on a bell curve of individual differences.

## Recognition

Baron-Cohen was awarded the 1990 Spearman Medal from the BPS, the McAndless Award from the American Psychological Association, the 1993 May Davidson Award for Clinical Psychology from the BPS, and the 2006 presidents' Award from the BPS.
He received an honorary degree from Abertay University in 2012, and was awarded the Kanner-Asperger Medal in 2013 by the Wissenschaftliche Gesellschaft Autismus-Spektrum as a Lifetime Achievement Award for his contributions to autism research. He was also knighted in the 2021 New Year Honours for services to people with autism.
Baron-Cohen's Mindreading and The Transporters special educational software were nominated for the British Academy of Film and Television Arts (BAFTA) awards in 2002 and 2007.
In 2023, he was awarded the Medical Research Council (MRC) Millennium Medal for his work on the prenatal sex steroid theory of autism and the transformative contributions to autism.

## Personal life

In 1987, Baron-Cohen married Bridget Lindley. Together, they had three children.
He has an elder brother Dan Baron Cohen and three younger siblings, brother Ash Baron-Cohen and sisters Suzie and Liz. His cousins include actor and comedian Sacha Baron Cohen and composer Erran Baron Cohen.

## Selected publications
### Single-authored books

* Mindblindness: An Essay on Autism and Theory of Mind. MIT Press/Bradford Books. 1995. ISBN 978-0-262-02384-9.
* The Essential Difference: Men, Women and the Extreme Male Brain. Penguin/Basic Books. 2003. ISBN 978-0-7139-9671-5.
* Autism and Asperger Syndrome. Facts. Oxford University Press. 2008. ISBN 978-0-19-850490-0.
* Zero Degrees of Empathy: A New Theory of Human Cruelty. Penguin/Allen Lane. 2011. ISBN 978-0-7139-9791-0. (published in the US as The Science of Evil: On Empathy and the Origins of Human Cruelty, ISBN 978-0-465-02353-0)
* The Pattern Seekers: A New Theory of Human Invention. Allen Lane. 2020. ISBN 978-0241242186. (published in the US as The Pattern Seekers: How Autism Drives Human Invention. Basic Books. 2020. ISBN 978-1541647145.)

### Other books

* Baron-Cohen S, Tager-Flusberg H, Lombardo MV, eds. (2013). Understanding Other Minds: Perspectives From Social Cognitive Neuroscience (3rd ed.). Oxford University Press. ISBN 978-0-19-852446-5.
* Hadwin J, Howlin P, Baron-Cohen S (2008). Teaching Children with Autism to Mindread: A Practical Guide for Teachers and Parents. Wiley. ISBN 978-0-471-97623-3.
* Baron-Cohen S, Lutchmaya S, Knickmeyer R (2005). Prenatal Testosterone in Mind: Amniotic Fluid Studies. MIT Press/Bradford Books. ISBN 978-0-262-26774-8.
* Baron-Cohen S, Wheelwright S (2004). An Exact Mind: An Artist with Asperger Syndrome. Jessica Kingsley. ISBN 978-1-84310-032-4.
* Baron-Cohen S; Tager-Flusberg H; Cohen DJ, eds. (2000). Understanding Other Minds: Perspectives from Developmental Cognitive Neuroscience (2nd ed.). Oxford University Press. ISBN 978-0-19-852445-8.
* Baron-Cohen S, Harrison J, eds. (1997). Synaesthesia: Classic and Contemporary Readings. Blackwells. ISBN 978-0-631-19763-8.
* Baron-Cohen S, ed. (1997). The Maladapted Mind: Classic Readings in Evolutionary Psychopathology. East Sussex, UK: Psychology Press/Taylor Francis Group. ISBN 978-0-86377-460-7.

### Selected journal articles

* Baron-Cohen S, Leslie AM, Frith U (October 1985). "Does the autistic child have a "theory of mind"?". Cognition. 21 (1): 37–46. doi:10.1016/0010-0277(85)90022-8. PMID 2934210. S2CID 14955234.
* Baron-Cohen S, Knickmeyer RC, Belmonte MK (November 2005). "Sex differences in the brain: implications for explaining autism" (PDF). Science. 310 (5749): 819–823. Bibcode:2005Sci...310..819B. doi:10.1126/science.1115455. PMID 16272115. S2CID 44330420.