Back in the first half of the 20th century, young children who had severe difficulties with communication and behavior were often labeled as having a childhood form of schizophrenia. According to the conventional wisdom of the time, “cold parenting”—from mothers in particular—was to blame.
Today, we would recognize many of those children as having autism, a diagnosis that didn’t officially exist until 1980. That milestone followed years of scientific research that ultimately identified autism as a complex neurodevelopmental disorder—not a mental health condition caused by emotionally detached moms. In the decades since, countless studies have deepened our understanding of autism, and the definition of the disorder has evolved: The formal medical term is now “autism spectrum disorder,” because it has become clear that the disorder varies widely in severity. While some people have profound impairments in communicating and socializing (talking little or not at all, for example), many others have relatively mild difficulties and lead typical lives.
Those decades of research have taught us something else: There is no single cause of autism. Study after study has shown that it has a very strong genetic component, and that certain factors during fetal development may raise the risk, too.
I’m bringing all of this up because we are unfortunately living in a time when our political leaders are seeking to discredit the science on autism. They want to take us backward, to the mindset that autism has a straightforward environmental cause that we can eliminate. Health and Human Services Secretary Robert F. Kennedy Jr. claims that autism is preventable, and that scientists “should have” figured it all out 20 years ago. In April, he announced that he was assembling a “world-class” team of scientists who would identify the root cause of autism—by September. Kennedy may not be blaming cold parents, but he is aggressively pushing the false narrative that an “environmental toxin” is the primary reason that autism exists. As health secretary, Kennedy has been deliberately vague about naming a suspect, but he has a well-known history of advancing the myth that vaccines cause autism.
While we wait to hear the results of this so-called world-class investigation into the underpinnings of autism, I think it’s a good time to take a look at some of Kennedy’s claims, and what the actual evidence shows.
The claim: Autism is an epidemic that must have an environmental cause. It’s true that autism is being diagnosed much more often now than decades ago. According to the latest figures from the Centers for Disease Control and Prevention (CDC), the prevalence of autism spectrum disorder among eight-year-old children in the U.S. stood at one in 31 in 2022. That’s up from one in 36 just two years prior, and represents a huge increase from 25 years ago, when the prevalence was one in 150.
Kennedy has seized on those figures as evidence of an “epidemic” being fueled by something toxic lurking in our environment. But he conveniently ignores the CDC’s own conclusions—that increased detection of autism spectrum disorder is the likely driver for almost all of this. For example, autism prevalence varies strikingly from state to state: California has the highest prevalence, at 53 per 1,000 children—compared with fewer than 10 per 1,000 in Texas. California also happens to devote more resources to detecting autism early, including a program that trains pediatricians in screening for the disorder. As the Autism Science Foundation points out, the CDC report actually offers convincing evidence that better screening and diagnosis (plus declining stigma around autism) explain the rising prevalence.
None of this, by the way, is new. Researchers have long attributed much of the increase in autism to changes in how we define the disorder (it’s now recognized as a spectrum); more and better screening (the American Academy of Pediatrics first recommended routine early-childhood screening in 2007); and greater awareness of autism in the general public (parents and, increasingly, adults are seeking evaluations for it).
The claim: Autism researchers have failed us. Kennedy has denounced the efforts of autism scientists, saying it is “unforgivable” that they’ve yet to give us “answers” on the disorder. As I’ve already pointed out, our understanding of autism has grown immensely over the past several decades, thanks to the work of dedicated scientists. The truth is, genes explain much of the risk for autism—60 to 90 percent, based on studies of twins. But experts also believe that there are prenatal factors that operate along with genetic vulnerability to cause autism in some children. Studies have pointed to a number of possible contributors—including preterm birth, being born to older parents, and heavy exposure to air pollution during fetal development. As for the notion that childhood vaccines cause autism, a raft of international studies has thoroughly debunked that claim.
It’s clear that there are no easy answers when it comes to autism. It is a complex brain-based disorder, and it has taken rigorous scientific research to help us better understand it. The only way forward is to continue that caliber of research—which cannot be accomplished in Kennedy’s timeline of a few months. Unfortunately, despite the pledge to get to the bottom of autism, the Trump administration has slashed funding for autism research overall.
The claim: Autism is a “tragedy” that “destroys families.” Kennedy has also recently drawn fire for grossly mischaracterizing people with autism, saying that children with the disorder will never hold a job, play sports, go on a date—essentially, will never lead full lives. But many studies have shown that the vast majority of people with autism do not have such severe limitations. And recent research has been highlighting the fact that while people with milder autism may communicate differently from people without autism, that does not necessarily mean they are impaired in their daily lives. Groups such as the Autism Society have rightfully called Kennedy out for dredging up harmful stereotypes about people with autism.
Final thoughts. It’s evident that the current administration is choosing to ignore established science on autism, as well as other public health matters, in service of advancing its own ideology. As we’ve stated on these pages before, we’re committed to critically scrutinizing the science. This is not about taking political sides. The best way to counter rhetoric and disinformation is to amplify true scientific evidence.
