A number of otherwise skeptical senators took at face value the pledge by Robert F. Kennedy Jr. at Senate hearings in January to “follow the science” on issues related to the causes of disease in the U.S., helping him receive confirmation as secretary of Health and Human Services.

As he demonstrated last week at his very first news conference as the government’s top healthcare official, he was blowing smoke.

The topic was what he described as an “alarming … epidemic” of autism, supposedly documented by a new report by the Autism and Developmental Disabilities Monitoring Network of the Centers for Disease Control and Prevention.

His advice was to ignore what decades of scientific research have established as contributors to the reported increase in autism prevalence. These include genetic factors; the ever-broadening definition of autism itself, now known as autism spectrum disorder, or ASD; and vastly improved screening programs nationwide.

The inescapable conclusion is that Kennedy’s HHS is in the grip of a pseudoscience revolution in which misinformation and disinformation are ascendant. The cost to scientific research generally and to households caring for those with chronic conditions such as ASD is incalculable.

Kennedy’s words left much of the autism community aghast. At both his news conference and an accompanying HHS press release, “Kennedy repeated false claims that autism was a ‘preventable’ ‘epidemic’” and that the CDC report’s findings “could not be explained by improved access to screening,” stated the Autistic Self Advocacy Network. ASAN accused Kennedy of having “cherry-picked” data and having misinterpreted basic science.

“It’s not that the amount of autism in the population has changed,” the network’s statement said — “it’s that more people are getting the tools necessary to get a diagnosis.”

Observes Holden Thorp, the editor of Science, who disclosed last year that he was diagnosed with autism at the age of 53 (he’s now 60), “almost everything in the CDC report talked about better identification and better diagnosis being the source of the increase. … The main recommendation is to get people more access to services.”

I asked HHS to provide me with Kennedy’s response to these and other criticisms, but didn’t receive a response.

Kennedy’s words were so averse to understanding the truth about autism that they deserve to be set forth here in some detail. To a great extent, they’re refuted by the CDC report itself, which Kennedy referred to repeatedly at his news conference. The CDC estimated the rate of autism in the general population at about one in 31 children born in 2014. That’s a higher rate than was found even two years earlier.

But it doesn’t amount to an “epidemic” that is “running rampant,” as Kennedy said. He said “most cases now are severe,” which is untrue. In fact, the vast majority of new cases involve children without the intellectual disabilities often associated with stereotypical autistic behavior, such as sensitivities to touch and an absence of verbal skills. The prevalence of more severe cases has actually declined in recent years, according to a 2023 study from Rutgers.

Kennedy took special aim at what he called “the ideology that … the relentless autism prevalence increases are simply artifacts of better diagnoses, better recognition or changing diagnostic criteria.” He said “this epidemic denial has become a feature in the mainstream media and it’s based on an industry canard” perpetrated by “people who don’t want us to look at environmental exposures.”

Well, no. The contributions made by updated diagnostic standards and improved screening to changes in prevalence rates aren’t concoctions of the media, but findings from professional research — including the CDC report.

Kennedy scoffed at research that has established a genetic component to autism, even though such findings have been conclusive; he implied that spending on such studies is a waste of money because the research is a “dead end.”

He painted a dire picture of the lives of autistic people. “Autism destroys families,” he said. “These are kids who will never pay taxes, never hold a job, they’ll never play baseball, they’ll never write a poem, they’ll never go out on a date, many of them will never use a toilet unassisted.”

Kennedy’s fans played the “what he really meant to say” game on social media, arguing that he was referring only to the most seriously impaired. But that distinction wasn’t clearly made either in the HHS press release or at Kennedy’s news conference. Just to be plain, given Kennedy’s effort to shroud autistic people in stigma, many pay taxes. Many hold jobs. Many play baseball. Many write poetry, go on dates, don’t need help to use a toilet.

Put it all together, and Kennedy’s performance raises urgent questions about whether he understands autism at all or is just using it as a stalking horse to promote his assertion that “environmental toxins” are the root of chronic diseases.

Kennedy’s erroneous ideas about autism aren’t new. He has long favored the long-debunked claim that autism is related to childhood vaccinations. He didn’t specifically mention vaccines during his appearance, but more than once he claimed that “someone is putting environmental toxins into … our medicines.”

What medicines have most children received by their second birthday, when autism is commonly diagnosed? Vaccines, that’s what.

Kennedy seemed impervious to the findings of scientific researchers. That was the conclusion of Peter Hotez, a leading vaccine expert whose daughter Rachel is autistic. In 2017, the National Institutes of Health asked Hotez to meet with Kennedy to move him off the hobbyhorse of a vaccine-autism link. “I couldn’t engage him,” Hotez told me. “But he was so deeply dug in about vaccines that he wasn’t interested in listening.”

His encounter with Kennedy was what prompted Hotez to write his 2018 book “Vaccines Did Not Cause Rachel’s Autism.”

The truth is that researchers have made great strides in unearthing the causes and characteristics of autism. They’ve identified some genetic anomalies that lead to a predisposition to the spectrum.

Scientists at the University of North Carolina, Stanford and UC Davis have found unusual prenatal growth patterns in the brain that appear to correlate with ASD diagnoses in early childhood, though it’s unclear what triggers that growth. Some have found evidence of environmental factors, chiefly experienced by women in pregnancy, though some question whether any such factors can be primary determinants of ASD.

Kennedy would have been well-advised to spend more time reading his own agency’s report before citing it at his news conference. That’s because it refuted much of what he claimed.

To begin with, the report took a more nuanced view of autism than the horrific picture he painted of autism sufferers. Throughout, it refers to ASD — “autism spectrum disorder” — rather than painting it as “autism” with a single broad brush, as he did. The report explicitly states that the change in reported prevalence of ASD “can reflect differing practices in ASD evaluation and identification,” as well as differences in the availability of services for autistic people and their families.

Among other factors, the report states that ASD diagnoses among Black, Hispanic and other ethnic groups have increased because those “previously underserved groups” have received “increased access to … identification services” in recent years. That has certainly contributed to the apparent increase in ASD prevalence overall.

Until about 10 years ago, the report notes, the highest prevalence of ASD was found among white children and those from wealthier neighborhoods, plainly those with both the incentive to track their children’s intellectual development and the best resources to obtain services. (Access to health insurance covering autism diagnosis and treatment also correlated with prevalence rates, the CDC found.) Black, Hispanic and other ethnic groups have been catching up.

The report further documented how reported rates of ASD are related to differing approaches to screening and diagnostic services among states and local communities. The reported ASD rate was 9.7 per 1,000 children in Texas, but 53.1 in California.

Why would it be so high in California? The report notes that California has trained local pediatricians to screen and refer children for assessment as early as possible — at an average of 36 months, compared with the Texas average of nearly 70 months — which “could result in higher identification of ASD, especially at early ages.” California, moreover, has established “regional centers throughout the state that provide evaluations and service coordination for persons with disabilities and their families.”

What is Kennedy’s endgame here? He portrays himself as a seeker of scientific truth, but throughout his news conference he denigrated scientists for purportedly ignoring what he said were clear signals of an autism epidemic rendering “thousands of profoundly disabled children somehow invisible.” In doing so, he overlooked decades of fruitful research efforts aimed at uncovering the causes and nature of autism.

He left the impression that research into genetic or prenatal causes will get short shrift in grants from the National Institutes of Health, which comes under his jurisdiction. Instead, he’ll favor studies aimed at identifying specific environmental toxins, although their significance is unclear. He has already indicated that he plans to revive research tying vaccines to autism, though that connection consistently has been disproved.

Perhaps most disturbing is that Kennedy showed almost no awareness of the diversity of ASD — and the contribution that it has made to humanity. “Some neurodivergent people are meticulously observant and are able to connect seemingly disparate concepts — assets in the world of science,” Thorp wrote in connection with his own diagnosis. “Neurodiversity scholars and advocates have stressed that autistic thinkers are responsible for many innovations and advances across human history.”

There’s reason to fear that Kennedy’s quest for a cause or even a cure for autism will shoulder aside other research more important for those with ASD. As Emily Hotez, Rachel Hotez’s older sister and a leading autism researcher at UCLA, noted in an article she co-wrote after the CDC report’s release, the effort to identify autism’s cause has overlooked “something far more urgent: improving the lives of autistic people and their families, here and now.”