Autism advocacy and research have a rich history, and they are beginning to attract much interest beyond the autism community. In this article, I will share some interesting history information about the autism field, as well as insights into several major developments over the past six decades.

Autism in books and film

In 1964, autism was a little-understood disorder widely believed by psychiatrists to be caused by “refrigerator parents.” That year, Dr. Bernard Rimland published his seminal book Infantile Autism: The Syndrome and Its Implications for a Neural Theory of Behavior, which is credited with revolutionizing the field of autism research and jump-starting biological research into the disorder [1].

Four years later, ARI—formerly the Institute for Child Behavior Research—produced the first documentary on autism, The Invisible Wall. The groundbreaking film can be viewed at In this documentary, Dr. Rimland, then 40 years of age, shared his views on genetics and the environment as underlying contributors to autism. Dr. Ruth Sullivan, who is often credited as the first parent advocate in the field, is also featured in the film.

Today, autism is the topic of many popular books and documentaries. Two of the most widely read books are In a Different Key, published in 2016 by John Donvan and Caren Zucker [2], and NeuroTribes, published in 2015 by Steve Silberman [3]. In a Different Key was nominated for a Pulitzer Prize in 2017 for general nonfiction, and NeuroTribes has received much media attention. Prior to publication, all three authors visited the Autism Research Institute (ARI) in San Diego to learn about Dr. Rimland and ARI and to visit with Mark, Dr. Rimland’s autistic son.

Donvan and Zucker have also produced a historical documentary on autism, and ARI contributed rare video footage for the film. The film trailer is available on youtube,

Prevalence rates

Until a few decades ago, autism was considered to be a relatively rare disorder. In 1966, Dr. Victor Lotter screened the entire population of 8- to 10-year-old children in the County of Middlesex, located in the southeastern region of the United Kingdom (UK) [4]. He identified 35 children on the spectrum, and, based on the population in the area, he estimated the prevalence rate to be 4.5 out of 10,000 children or nearly 1 in 2,000. In 1978, Dr. Lotter screened more than 1,300 children at institutions for people with intellectual disability in six African countries and found only nine children who qualified for a diagnosis and 30 others with features of autism [5].

Since the 1960s and 1970s, the number of children diagnosed with autism has climbed rapidly. Based on data collected in 2018, the Centers for Disease Control and Prevention (CDC) now estimates the prevalence rate of autism to be 1 in 44 [6].


In 1943, Dr. Leo Kanner often considered the father of child psychiatry, described in great detail 11 children who shared very similar symptoms and behaviors [7]. This article is considered by many to be the first official recognition of autism in a science-based journal. Donald T., the first case described in Kanner’s paper, is now in his late 80s.

In 1961, the British Working Party, directed by Dr. Mildred Creek and consisting of 13 members from various clinics and hospitals in the UK, established nine criteria for diagnosing autism [8]. In short, these included: impairment of emotional relationships with people, unawareness of one’s own identity, preoccupation with particular objects, resistance to change, impairment in perception, illogical anxiety, speech loss or a failure to develop any speech, and a “distortion in motility patterns.”

Three years later, Dr. Rimland published a diagnostic checklist in the appendix of his 1964 book [1]. Titled “Diagnostic Check List for Behavior-Disturbed Children,” it was developed primarily to diagnose classical autism or Kanner’s syndrome. Four years after that, in 1968, the American Psychiatry Association’s Diagnostic and Statistical Manual (DSM), version II, used the term “autistic” as part of the diagnostic criteria for childhood schizophrenia for the first time [9]. Twelve years later, in 1980, autism had its own category in the DSM-III and was referred to as “infantile autism” [10].

The DSM’s definition of autism spectrum disorders continues to change with each new edition. For example, controversy arose when the category of “Asperger syndrome” was removed in the latest edition, potentially affecting services for many on the spectrum.


In 1964, Dr. Rimland argued in support of a genetic basis of autism (chapter 7) [1]. Thirteen years later, in 1977, Folstein and Rutter counted the number of same-sex children in 21 sets of twins in which one or both had autism [11]. They reported 36 percent co-occurrence in monozygotic or identical twins (i.e., 100 percent overlap in genes) and 0 percent in dizygotic or fraternal twins (50 percent overlap in genes). These results supported Rimland’s 1964 conclusion.

Today, there is overwhelming evidence that genetics plays an instrumental role in autism, with at least 20 percent of cases attributed to an underlying genetic cause. This is often referred to as syndromic autism [12]. There is also mounting evidence of a genetic susceptibility to certain toxins in the environment, which may explain the other 80 percent. These toxins include pesticides, particulate matter (found in car and truck exhaust), plastics, and heavy metals [13].

Neurostructural findings

In his 1964 book, Dr. Rimland proposed that a specific neural structure, the reticular formation (RF), was impaired in autism (see chapter 6) [1]. The RF, located in the center of the brainstem, is instrumental in regulating arousal level and is related to alertness, consciousness, and sleep. Over the years, researchers have not found significant impairment in the brainstem; however, electrophysiological research has reported some dysregulation [14].

Two decades later, in 1985, Drs. Margaret Bauman and Thomas Kemper published the first brain autopsy study on a 29-year-old autistic individual [15]. Several neural structures were shown to be impaired, including the amygdala, hippocampus, mamillary body, and neocerebellar cortex. This study received international attention, including a featured story in the Boston Globe.

Today, as Dr. David Amaral and his colleagues at the MIND Institute note, “Postmortem and structural magnetic resonance imaging studies have highlighted the frontal lobes, amygdala, and cerebellum as pathological in autism” [16].  However, the researchers conclude that “there is no clear and consistent pathology that has emerged for autism,” adding that “recent studies emphasize that the time course of brain development rather than the final product is most disturbed in autism.”


Pioneering researchers in Southern California were instrumental in transitioning the field of autism from a psychogenic (parent-blaming) perspective to a biological perspective. Initially, the Neuropsychiatric Institute, or NPI, at UCLA took a lead role in investigating interventions that included biological and behavioral treatments. Dr. Edward Ritvo and his colleagues experimented with various drugs, while Dr. O. Ivar Lovaas treated challenging behaviors using behavior modification techniques.

Within a short period of time, there were significant disagreements among these researchers regarding the efficacy and adverse side effects of their treatments. Soon after, Lovaas moved his research laboratory to the psychology department, located on the other side of UCLA’s campus.

Today, there continues to be controversy over both drug and behavioral treatments for autism. One of the most important changes in this area is that individuals with autism are gaining a long-overdue voice in this conversation, serving on policy-making boards and participating in the design of research studies.

The Autism Research Institute plans to celebrate its fifty-fifth anniversary this year by opening a museum dedicated to the history of autism in the fall of 2022.  The museum will include exhibits, artifacts, little-known but important facts about autism, and original artworks.


References are available at

This editorial originally appeared in Autism Research Review International, Vol. 36, No. 3, 2022

Past issues of Autism Research Review International are available online at 

ARI’s Latest Accomplishments

April 15th, 2024|News|

Connecting investigators, professionals, parents, and autistic people worldwide is essential for effective advocacy. Throughout 2023, we continued our work offering focus on education while funding and support research on genetics, neurology, co-occurring medical