Karolinska Institutet Psychology Speaker Series: Sir Simon Baron-Cohen

Sir Simon Baron-Cohen, Professor in the Departments of Psychology and Psychiatry University of Cambridge and Fellow at Trinity College, Cambridge. He is Director of the Autism Research Centre in Cambridge and the author of several influential books, such as Mindblindness, Prenatal Testosterone in Mind, Zero Degrees of Empathy, and The Pattern Seekers. He has published over 600 peer reviewed scientific articles, contributing to our knowledge of autism, typical cognitive sex differences, and synaesthesia. Three influential theories he formulated were the ‘mindblindness’ theory of autism (1985), the ‘prenatal sex steroid’ theory of autism (1997), and the ‘empathizing-systemizing’ theory of typical sex differences (2002).

The prenatal sex steroid theory of autism

Autism is diagnosed in 1 in 25 boys and 1 in 100 girls. This biased sex ratio appears to be true even after taking into account under-diagnosis of females. Autism is strongly genetic but the genes associated with autism must interact with epigenetic factors, given the existence of discordant monozygotic twins. One candidate biological epigenetic mechanism that could explain the biased sex ratio in autism is prenatal sex steroid hormones, since these play a role in ‘masculinizing’ the brain. I summarize work from our lab showing how levels of prenatal sex steroid hormones, such as androgens and estrogens, are associated with typical individual differences in empathy, systemizing and autistic traits, and are elevated in autistic people.