Fact-checking RFK Jr’s false claim linking autism to circumcision

United States Health and Human Services Secretary Robert F Kennedy Jr claimed connected October 9 that determination whitethorn beryllium a nexus betwixt autism and circumcision. However, experts accidental his claims are not based connected rigorous and robust research.

“There’s 2 studies that amusement children who are circumcised aboriginal person treble the complaint of autism, and it’s highly apt due to the fact that they’re fixed Tylenol,” said Kennedy, who, similar President Donald Trump, cited shaky probe astir the cause and autism erstwhile informing pregnant women against taking the acetaminophen.

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Circumcision is the removal of penis foreskin, a typically elective process performed connected infants mostly for spiritual and taste reasons.

We looked astatine the studies, 1 from 2013 and different from 2015.

Neither showed that circumcision causes autism. Neither had information connected whether acetaminophen, the progressive constituent successful Tylenol, was fixed to the patients successful the studies.

The 2 papers recovered immoderate relation betwixt circumcision and autism, but some had important limitations, including tiny illustration sizes.

Authors of some papers advised further probe to corroborate a relationship.

Decades of probe amusement that acetaminophen is harmless for infants and children erstwhile utilized arsenic recommended and nether a paediatrician’s guidance. No probe shows that taking the cause arsenic a kid causes accrued autism risk.

Acetaminophen is not universally recommended for circumcisions. Infant circumcision is typically performed with a section anaesthetic. Some infirmary guidelines counsel parents to springiness infants acetaminophen arsenic needed for symptom successful the days pursuing the procedure.

Asked astir Kennedy’s statements connected circumcision, a Health and Human Services Department spokesperson pointed america to the secretary’s October 10 station connected X successful which helium pointed to the 2015 survey and an unpublished probe insubstantial from 2025.

As usual, the mainstream media attacks maine for thing I didn’t accidental successful bid to distract from the information of what I did say.

At yesterday’s Cabinet meeting, I said: “There are 2 studies that amusement children who are circumcised aboriginal person treble the complaint of autism, and it’s highly…

— Secretary Kennedy (@SecKennedy) October 10, 2025

Unpublished nonfiction not caller research

The 2025 insubstantial Kennedy referenced successful his X station has not been peer-reviewed. It is considered a preprint, which means it has not been vetted by different technological experts successful the field, a modular process for scholarly probe that aims to guarantee its prime and rigour anterior to publication.

The insubstantial was authored by researchers astatine WPLab, a North Carolina company that promotes a link between acetaminophen and autism. In September, The Atlantic reported that WPLab CEO William Parker, a retired Duke University subordinate professor, has been successful predominant interaction with Kennedy.

The WPLab insubstantial starts by saying successful its abstract that “overwhelming evidence” shows acetaminophen vulnerability successful babies “triggers galore if not astir cases of autism spectrum disorder”. The institution makes akin statements astir causation successful respective different papers, but that presumption does not bespeak technological consensus.

The premise of the nonfiction posted this summertime is that “evidence that acetaminophen triggers autism” has been “ignored and mishandled” successful existing published research. It is simply a critique and analysis; it does not correspond immoderate caller technological research. It points to the 2013 and 2015 studies astir circumcision and autism, but misrepresents the scope of the 2015 study’s findings. It does not explicate that the 2013 survey was a basal population-level look astatine circumcision rates and autism rates.

2013 survey a ‘hypothesis generating’ exercise

Authored by UMass-Lowell epidemiologists, the 2013 peer-reviewed survey aimed to spot if determination was an relation (not causation) betwixt giving young infants acetaminophen and processing autism. The survey was described by the authors arsenic a “hypothesis generating exploratory analysis”, meaning it was not intended to scope a decision astir a link.

Circumcision was not the focus. Data astir the process was analysed arsenic if it were a proxy for giving Tylenol to a baby. But the survey did not corroborate whether the cause was fixed successful the cases it cited.

The survey looked astatine 9 countries. For each country, it collected 2 pieces of data: the percent of the colonisation that was circumcised and its prevalence of autism successful men. In immoderate cases, the circumcision complaint was estimated based connected the fig of Jewish and Muslim men successful a country.

It utilized those fewer pieces of information to cipher a correlation.

“You can’t truly bash a correlation with immoderate level of legitimacy from a statistical constituent of presumption connected specified a tiny illustration size,” said Helen Tager-Flusberg, prof emerita astatine Boston University and laminitis of the Coalition of Autism Scientists.

The survey said determination was a affirmative relation betwixt a population’s circumcision rates and its autism rates, but cautioned determination were “significant limitations” to the survey and that “correlation is not causation and arsenic specified nary causal inference is intended”. The authors called for much probe to “confirm oregon disprove this association”.

Despite having nary information connected whether kids represented successful the information were fixed acetaminophen, the survey linked the uncovering to the drug’s usage by looking astatine information from earlier 1995, astir the clip erstwhile acetaminophen became a tested treatment for circumcision-related pain. The survey recovered a somewhat weaker correlation pre-1995.

2015 survey was successful Denmark, wherever circumcision is rare

The 2015 Danish study explored whether being circumcised meant a lad was much apt to beryllium diagnosed with autism earlier property 10. The survey did not analyse acetaminophen use.

The survey recovered that the hazard of autism was 46 to 62 percent accrued successful boys who were circumcised, but this uncovering needs a batch of context.

First, circumcision successful Denmark is uncommon and happens mostly among Jewish and Muslim families. But the survey had lone circumcision information from hospitals and doctors’ offices, meaning it did not number procedures that happened successful location spiritual ceremonies.

Additionally, due to the fact that circumcision and autism diagnoses are some uncommon, those groups’ illustration sizes were small. In a survey of 342,877 boys calved betwixt 1994 and 2003, less than 1 percent (3,347 boys) were circumcised, and astir 1.5 percent (5,033 boys) had autism. Just 57 boys had both.

“We’re talking astir a comparatively tiny fig of children retired of this precise ample Danish population,” Tager-Flusberg said. When the survey broke the samples down by religion groups oregon eliminated incomplete information from the analysis, its findings were much melodramatic but based connected adjacent smaller numbers. The uncovering of a 62 percent accrued hazard of autism was based connected conscionable 24 boys. Other researchers successful the tract publically criticised the survey for issues with its methods.

In 2019, 1 of the study’s authors, Morten Frisch, projected that the Danish Parliament should prohibit circumcision until the property of 18.

Although the 2015 survey did not look astatine acetaminophen use, the WPLab insubstantial cited it arsenic “some of the astir compelling ‘standalone’ grounds that acetaminophen triggers autism successful susceptible babies and children” – a connection Kennedy quoted from successful his X post.

“Neither of these studies instrumentality into information a full scope of imaginable taste demographic oregon different confounding variables that 1 indispensable ever beryllium alert of erstwhile looking astatine associations betwixt immoderate benignant of hazard origin and autism,” Tager-Flusberg said.