Centers for Disease Control and Prevention reported that 1 in 68 children are identified with Autism Spectrum Disorder (ASD) (CDC, 2016a). Boys are nearly five times more likely (1 in 42) than girls (1 in 189) to have autism.
Studies hypothesize that the extreme male brain theory implicates the differences between the male and female ratios of autism (Baron-Cohen, 2002; Baron-Cohen & Hammer, 1997). Moreover, on average, females have a stronger drive to empathize and males have a stronger drive to systemize (Baron-Cohen, 2010). Baron-Cohen and Hammer (1997) further state that, on average, there are differences in cognitive styles between sexes that results in differential socialization and or biological predispositions in brain development.
Together with biological and genetic factors, environmental factors contribute to many causes for multiple types of autism (CDC, 2016b). Risk factors and causes for autism are not all known; however, scientists agree that:
Genes can contribute to the likelihood of a person developing ASD
Children of adult siblings with ASD have a higher predisposition of also having ASD
ASD tends to occur more in individuals with certain genetic or chromosomal conditions
Exposure to valproic acid and thalidomide inutero have been linked to ASD
There’s a greater risk of having ASD with maternal and paternal age at conception
Geneticist Wendy Chung beautifully summarizes what we’ve learned about autism through studies and treatments.
Baron-Cohen, S. (2002). The extreme male brain theory of autism. Trends in Cognitive Sciences, 6, 248-254.
Baron-Cohen, S. (2010). Empathizing, systemizing, and the extreme male brain theory of autism. Progress in brain research, 186, 167-175.
Baron-Cohen, S., & Hammer, J. (1997). Is autism an extreme form of the" male brain"?. Advances in Infancy research, 11, 193-218.
Baron-Cohen, S., Knickmeyer, R. C., & Belmonte, M. K. (2005). Sex differences in the brain: implications for explaining autism. Science, 310(5749), 819-823.
Centers for Disease Control and Prevention. (2016a). Autism spectrum disorder (ASD): Facts about ASD. Retrieved from https://www.cdc.gov/ncbddd/autism/research.html
Centers for Disease Control and Prevention. (2016b). Autism spectrum disorder (ASD): Research. Retrieved from https://www.cdc.gov/ncbddd/autism/research.html
Chung, W. (2014). Autism—what we know (and what we don’t know yet). Ted Talks. Retrieved https://www.youtube.com/watch?v=wKlMcLTqRLs