Causes of Autism Spectrum Disorders

Historical Context

Let's go back to the previous discussion on the medical model of disability. People with ASD seemed to have been represented in the medical literature since the late 19^th century, although this was often associated with mental illness. In the 1960s, a psychologist named Bruno Bettelheim did quite a bit of damage to societal perceptions about ASD by suggesting it was caused by “refrigerator mothers.” The mothers of children with ASD were characterized as cold and distant--but only the mothers! Mothers were also often stereotyped as being highly educated and more career oriented than other mothers. This theory did a lot of damage by blaming parents. Sometimes, you will still hear today how poor parenting, or a cold mother is the cause of a child having ASD, even though the theory has been soundly disproven.

Genetics

As your text states, research clearly has indicated that genetics may influence the likelihood of developing ASD. Unfortunately, we still do not know the extent of the relationship or the exact gene(s) that may be causing ASD. However, we do know that siblings have a greater risk of developing ASD. This is particularly true if we look at twins; if one twin has autism, there is a 90% chance that the other will as well. This provides a very strong indication of a genetic link, since identical twins are so similar. We also find that, if we look back in time, very often, a child who has been diagnosed with ASD may have a family member with some characteristics, even if that family member did not receive a formal diagnosis of ASD. So, we're seeing a strong genetic link occurring, but at this point in time, we still cannot pinpoint the exact gene(s).

This does have important implications, however. We know this comes under controversy when we consider that the possibility of identifying genetic markers for ASD may subject children (and their families) to selective termination, as has happened for children with Down syndrome and other disabilities with a genetic profile. Many autistic self-advocates and their parents have expressed concerns about this.

Role of the Environment

Although genetics plays a part in the development of ASD, it is generally acknowledged that genetic makeup alone does not account for all incidences. Many believe that the environment may also play a role. Environmental factors can include such toxins as pesticides or household cleaning agents, though the role of toxins still is widely debated. In fact, there still is controversy about whether the mercury in vaccines (now absent) causes ASD. Despite resounding evidence to the contrary, the theory of this environmental toxin continues to this day. Because environmental factors can refer to anything other than changes in a gene’s DNA, environmental risk factors for ASD may also include things like parental age at conception, maternal nutrition, infection during pregnancy, and prematurity. See this resource which discusses some of the controversies around ASD causality, which some people (parents, professionals, and even organizational leaders) still believe. Consider how this may influence people’s decision-making (e.g., gluten diets) and people’s perceptions about other families’ decision-making.