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== Extreme Male Brain Theory == | == Extreme Male Brain Theory == | ||
A major controversial theory of the etiology (cause) of ASD is known as the extreme male brain theory. The theory first proposed by the world famous autism researcher from the University of Cambridge, Simon Baron-Cohen, states that the major cause of ASD is excessive exposure to androgens (male sex hormones) during prenatal development. '''Baron-Cohen does not claim that persons with ASD are more 'masculine' then neuro-typicals, a point often lost on laymen'''. Baron-Cohen merely asserts that this 'extreme' masculinity takes form in a deficit of empathy in ASD individuals, as well as an increase in their mental tendency to attempt to systemise information they receive from the external environment, which a major cause of the obsessional interests and social deficits displayed by those with the disorder. The theory is supported by analysis on the amniotic fluid of children who were later diagnosed with ASD, which found evidence of elevated androgens (androstenedione and testosterone) in the placental fluid.<ref>https://www.ncbi.nlm.nih.gov/pubmed/24888361?dopt=Abstract</ref> However the relationship between these factors is likely complex; as later studies have also found evidence of elevated levels of estrogens in the pre-natal environment of those later diagnosed with autism<ref>https://www.sciencedaily.com/releases/2019/07/190729094538.htm/</ref>. This is likely partially due to the [https://en.wikipedia.org/wiki/ | A major controversial theory of the etiology (cause) of ASD is known as the extreme male brain theory. The theory first proposed by the world famous autism researcher from the University of Cambridge, Simon Baron-Cohen, states that the major cause of ASD is excessive exposure to androgens (male sex hormones) during prenatal development. '''Baron-Cohen does not claim that persons with ASD are more 'masculine' then neuro-typicals, a point often lost on laymen'''. Baron-Cohen merely asserts that this 'extreme' masculinity takes form in a deficit of empathy in ASD individuals, as well as an increase in their mental tendency to attempt to systemise information they receive from the external environment, which a major cause of the obsessional interests and social deficits displayed by those with the disorder. The theory is supported by analysis on the amniotic fluid of children who were later diagnosed with ASD, which found evidence of elevated androgens (androstenedione and testosterone) in the placental fluid.<ref>https://www.ncbi.nlm.nih.gov/pubmed/24888361?dopt=Abstract</ref> However the relationship between these factors is likely complex; as later studies have also found evidence of elevated levels of estrogens in the pre-natal environment of those later diagnosed with autism<ref>https://www.sciencedaily.com/releases/2019/07/190729094538.htm/</ref>. This is likely partially due to the [https://en.wikipedia.org/wiki/Aromatase aromatization] of the elevated androgens to female sex hormones, and there is animal evidence that pre-natal estrogens can have a "paradoxical" masculinzing effect in the right context. | ||
The complementary imprinted brain theory puts psychotic spectrum disorders (such as schizophrenia) on the opposite end of a spectrum from ASD, purportedly resulting from a conflict in the genomic imprinting between paternal and maternal genes, with an extreme genomic imprinting in favor of paternal genes being associated with ASD<ref>https://www.psychologytoday.com/intl/blog/the-imprinted-brain/201506/testing-the-extreme-female-brain-theory-psychosis</ref>. This also corresponds with sex differences in empathizing vs systemizing <ref>https://www.pnas.org/content/115/48/12152?fbclid=IwAR0ngaYIo88A77EKpALefnsr54ZZpPWGbatCYNPBcC84HgcDGmsZ2c6VgB4</ref>, which find females are generally higher in empathizing and males highest in systemizing, with autistic individuals of both sexes typically displaying a more masculinized behavioral phenotype. These developmental theories are not necessarily mutually exclusive with the theories of ASD that attribute the etiology of the disorder to greater mutational load.<ref>https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5895441/</ref> | The complementary imprinted brain theory puts psychotic spectrum disorders (such as schizophrenia) on the opposite end of a spectrum from ASD, purportedly resulting from a conflict in the genomic imprinting between paternal and maternal genes, with an extreme genomic imprinting in favor of paternal genes being associated with ASD<ref>https://www.psychologytoday.com/intl/blog/the-imprinted-brain/201506/testing-the-extreme-female-brain-theory-psychosis</ref>. This also corresponds with sex differences in empathizing vs systemizing <ref>https://www.pnas.org/content/115/48/12152?fbclid=IwAR0ngaYIo88A77EKpALefnsr54ZZpPWGbatCYNPBcC84HgcDGmsZ2c6VgB4</ref>, which find females are generally higher in empathizing and males highest in systemizing, with autistic individuals of both sexes typically displaying a more masculinized behavioral phenotype. These developmental theories are not necessarily mutually exclusive with the theories of ASD that attribute the etiology of the disorder to greater mutational load.<ref>https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5895441/</ref> |
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