The Understanding Autism project is devoted to understanding the factors that have led to the increase in autism prevalence over the last four decades. Since receiving the National Institutes of Health Pioneer Award, we have made significant progress in ascertaining individual and community level factors that are associated with an increased risk of autism.  Specifically, among other contributions, we have found evidence that points to new understandings of the expression of risk factors, of the role of de novo mutations in increasing risk, of spatial clustering at birth and diagnosis, which points to social dynamics as underlying risks of diagnosis, and of changes to the diagnostic pathway in relation to intellectual disabilities. We are rapidly expanding our data structures, analyzing new mechanisms associated with increased risk of autism, and understanding in greater detail the developmental trajectories of persons with autism. In addition to quantitative data, the project has collected life histories from individuals who have children with autism.

Current NIH support is for a project that contributes to public health by building and analyzing a unique population-level dataset designed to assess the association between Assisted Reproductive Technology (ART) and its subtypes and Autism, Intellectual Disability, and Cerebral Palsy as well as investigate heterogeneity in risk and the factors that may affect the associations. This will better enable individuals and their health care providers to weigh the risks and benefits of ART procedures and to identify potential modifiable risk factors for autism and other developmental disabilities.


National Institutes of Health (2018-2021)
National Institutes of Health Pioneer Award (2007-2012)


  • Mazumdar, S., King, M., Liu, K., Zerubavel, N., & Bearman, P. (2009). The Spatial Structure of Autism in California, 1993-2001. Health and Place, Volume 16: 539-546. [Read More]

  • King, M. & Bearman, P. (2009). Diagnostic Change and Increased Prevalence of Autism. International Journal of Epidemiology, Volume 38, Issue 5:1224-1234. [Read More]

  • King, M., Fountain, C., Dakhlallah, D., & Bearman, P. (2009) Estimated Autism Risk and Older Reproductive Age. American Journal of Public Health, Volume 99, Issue 9:1673-1679. [Read More]

  • Keyes, Kerry, Ezra Susser, Keely Cheslak-Postava, Christine Fountain, Ka-Yuet Liu, Soumya Mazumdar, and Peter Bearman. (2011). “Age, Period, and Cohort Effects in Autism Incidence in California from 1994 to 2005.” International Journal of Epidemiology. 2011; doi: 10.1093/ije/dyr193

  • Bearman, Peter. (2010). “Just-so Stories: Vaccines, Autism, and the Single-bullet Disorder.” Social Psychological Quarterly. 73(2): 112-115.

  • Liu, K., Zerubavel, N., & Bearman, P. (2010). Social Demographic Change and Autism. Demography, Volume 47, Issue 2:327-343 [Read More]

  • Liu, K., King, M., & Bearman, P. (2010). Social Influence and the Autism Epidemic. American Journal of Sociology, Volume 115, Number 5:1387-1434. [Read More]  (Eliot Freidson Outstanding Publication Award, Medical Sociology Section of the American Sociological Association, 2010-11)

  • Fountain, C., King, M., & Bearman, P. (2011). Age of diagnosis for autism. Journal of Epidemiology and Community Health, Volume 65: 503-510. [Read More]

  • Fountain, C. & Bearman, P. (2011). Risk as a social context. Sociological Forum, Volume 26, Issue 2:215-240. [Read More]

  • Cheslack-Postava,K., Liu,K. & Bearman,P.S. (2011) Closely Spaced Pregnancies are Associated with Increased Odds of Autism in California Sibling Births. Pediatrics, Volume 127: 246-253. [Read More]

  • King, M., & Bearman, P. (2011). Socioeconomic Status and the Increased Prevalence of Autism in California. American Sociological Review, Volume 76, Issue 2:320-346. [Read More]

  • Keyes, K., Susser, E., Cheslack-Postava, K., Fountain, C., Liu, K., and Bearman, P.S. (2011) Cohort Effects Explain the Increase in Autism Diagnosis among Children Born from 1992 to 2003 in California. International Journal of Epidemiology. [Read More]

  • Fountain, C., Winter, A.S., & Bearman, P.S. (2012) Six Developmental Trajectories Characterize Children with Autism. Pediatrics. Volume 129, Number 5: e1112-e1120. [Read More]

  • Mazumdar, S., Liu, K., Susser, E., & Bearman, P.S. (2012) The Disappearing Seasonality of Autism Conceptions in California. PLoS One, Volume 7, Issue 7:e41265. [Read More]

  • Fountain, Christine, Alix Winter, and Peter S. Bearman. (2012). “Dynamic Trajectories of Children with Autism.” Pediatrics. 129(5):e111-e112

  • Fountain, Christine and Peter Bearman. (2012). “Risk as Social Context: Immigration Policy and Autism in California.” Sociological Forum. 26(2): 215-240.

  • Liu, K., & Bearman, P. S. (2015). Focal points, endogenous processes, and exogenous shocks in the autism epidemic. Sociological methods & research, 44(2), 272-305.. [Read More]

  • Mazumdar, S., Winter, A., Liu, K., & Bearman, P. (2013) Spatial clusters of autism births and diagnoses point to contextual drivers of increased prevalence. Social Science and Medicine. [Read More]

  • Cheslack-Postava, K; K. Liu, E. Susser, A. Winter, and P.S Bearman. Can Sibling Sex Ratios be used as a valid test of the prenatal androgen hypothesis of autism spectrum disorders? PLOS-1. October 23, 2015. 10 (10), e0141338

  • Makovi, K, A. Winter, KY Liu, and Peter Bearman. (2015). The Population Level Impacts of Differential Fertility Behavior of Parents of Children with Autism.  Sociological Science. 2:398-419.

  • Fountain, Christine, Yujia Zhang, Dmitry M. Kissin, Laura A. Schieve, Denise J. Jamieson, Catherine Rice, Peter Bearman. (2015). Association Between ART Conception and Autism in California 1997-2007. American Journal of Public Health. 105 (5), 963-971

  • Laura A Schieve, Christine Fountain, Sheree L Boulet, Marshalyn Yeargin-Allsopp, Dmitry M. Kissin, Denise J Jamieson, Catherine Rice, Peter Bearman. (2015). “Does Autism Diagnosis Age or  Symptom Severity Differ Among Children According to Whether Assisted Reproductive    Technology was used to Achieve Pregnancy?” Journal of Autism and Developmental Disorders. pp1-13. PMID: 25997596

  • Kissin, DM, Yujia Zhang, Christine Fountain, Peter Bearman and LA. Schieve. (2015). Association of Assisted Reproductive Technology (ART) Treatment and Parental Infertility Diagnosis with Autism in ART-Conceived Children”. Human Reproduction. 30(2):454-65