Circumcision and autism

A new study suggests a link between ritual circumcision and the development of autism spectrum disorder (ASD). The suggested causal connection lies in the great pain that the infant suffers during the procedure.

Here is the abstract of the paper Ritual circumcision and risk of autism spectrum disorder in 0- to 9-year-old boys: national cohort study in Denmark by Morten Frisch and Jacob Simonsen published in the Journal of the Royal Society of Medicine, January 8, 2015. (The full paper is also available at the link.)

Objective Based on converging observations in animal, clinical and ecological studies, we hypothesised a possible impact of ritual circumcision on the subsequent risk of autism spectrum disorder (ASD) in young boys.

Design National, register-based cohort study.

Setting Denmark.

Participants A total of 342,877 boys born between 1994 and 2003 and followed in the age span 0–9 years between 1994 and 2013.

Main outcome measures Information about cohort members’ ritual circumcisions, confounders and ASD outcomes, as well as two supplementary outcomes, hyperkinetic disorder and asthma, was obtained from national registers. Hazard ratios (HRs) with 95% confidence intervals (CIs) associated with foreskin status were obtained using Cox proportional hazards regression analyses.

Results With a total of 4986 ASD cases, our study showed that regardless of cultural background circumcised boys were more likely than intact boys to develop ASD before age 10 years (HR = 1.46; 95% CI: 1.11–1.93). Risk was particularly high for infantile autism before age five years (HR = 2.06; 95% CI: 1.36–3.13). Circumcised boys in non-Muslim families were also more likely to develop hyperkinetic disorder (HR = 1.81; 95% CI: 1.11–2.96). Associations with asthma were consistently inconspicuous (HR = 0.96; 95% CI: 0.84–1.10).

Conclusions We confirmed our hypothesis that boys who undergo ritual circumcision may run a greater risk of developing ASD. This finding, and the unexpected observation of an increased risk of hyperactivity disorder among circumcised boys in non-Muslim families, need attention, particularly because data limitations most likely rendered our HR estimates conservative. Considering the widespread practice of non-therapeutic circumcision in infancy and childhood around the world, confirmatory studies should be given priority.

You can read more about the study at Machines Like Us.

In the paper, the authors state that circumcision creates a lot of pain and think that this could be a plausible mechanism to explain the correlation between circumcision and the later onset of ASD.

Negative long-term psychological consequences of pain- and stressful surgery in early childhood were described almost 70 years ago. Among children operated for a variety of conditions, Levy noted a strong association between the age at operation and the frequency and severity of emotional sequelae. Psychological problems were encountered in 42% of children aged < 3 years at the time of operation, as compared with 10% among older children. Until recently, it was believed that newborns are incapable of interpreting noxious stimuli in a manner comparable to that of older children and adults. This idea has now been abandoned with almost universal consensus that newborns and infants perceive pain and stress very much like older children and adults. … To our knowledge, no study has examined the possible association of circumcision-related pain and stress with boys’ subsequent risk of developing autism spectrum disorder (ASD). This is surprising, because painful experiences in neonates have been shown in animal and human studies to be associated with long-term alterations in pain perception, a characteristic often encountered among children with ASD.

One should be careful about taking action on the basis of one study and the authors rightly urge others to also to look into the issue. The single and now highly discredited study by the disgraced physician Andrew Wakefield that purportedly showed a link between the use of vaccines and the onset of autism in children has been seized upon by some and resulted in significant numbers of people not vaccinating their children. As a result, not only have efforts to completely eradicate many diseases been hindered, there has actually been a resurgence in diseases such as measles in countries like the US and the UK.

But the Wakefield study was methodologically problematic with a tiny sample and violations of normal research protocols. Furthermore, the consequences of the suggested remedy (not vaccinating) have been hugely deleterious. In this case, the study seems to be much better designed, with a huge sample, and the suggested action (not circumcising) not only has no negative consequences, it has many other things in favor of it, not the least of it is that a child, even an infant, has the right to bodily integrity and to not have others make decisions about it. If people want to get circumcised, they can do it to themselves as adults.

Of course, in this case not circumcising goes against the religious beliefs of Jews and Muslims so it will be interesting to see their reaction. Do they think that fidelity to their imaginary god is more important than the possible negative health consequences to their child?


  1. says

    Another fraudulent and oft repeated study involves male genital cutting, the lie that it reduces the spread of HIV. The time when men were healing fron the cutting -- and thus could not engage in sex -- was included in the “data”. When the false data was taken way, cut men were more likely to transmit the disease. As with Wakefield’s fraud, the lie has gone around the world several times before the truth got its boots on.


    The RCT lead authors all held pre-existing beliefs as to the “benefits” of male circumcision and cited articles that supported their pro-male circumcision opinions.

    There is a risk that contradictory evidence was also omitted in their institutional review board submissions. When undertaking research into male circumcision, full disclosure of personal beliefs indicative of likely biases should include professional, religious, political and cultural affiliations, as well as one’s own circumcision status.

    Making unwarranted recommendations in relation to circumcision policy raises the vista of future litigation. WHO/UNAIDS have uncritically accepted the African female-to-male reports as conclusive and have recommended male circumcision as an HIV-preventive measure despite substantial contradictory evidence, including the Wawer et al RCT itself which appears to have shown a 61% relative increase in HIV transmission from circumcised men to their female sexual partners some of whom were not informed that their male partners were HIV-positive.

    People who have preconceived biases are willing to believe errors and lies from disreputable sources. And they are unwilling to check facts even when they come from reputable ones, especially when they know or are afraid of having their opinions debunked (see also: welfare and drug testing in the US, police targeting black people disproportionaty in comparison to crimes committed by white people, etc.).

    Continued in a second comment to circumvent the anti-spam software….

  2. says

    …from above:

    Here’s a video worth watching on the subject: Child Circumcision: An Elephant in the Hospital

    Another good point I read recently said women should be against genital cutting. It reduces natural male lubrication and increases the time it takes men to reach orgasm, requiring much more stimulation than an intact penis requires. That means women could be subjected to prolonged and painful periods of penetration, leading to injuries and infections. Unmutilated men are the safer and healthier option for women.

  3. Pierce R. Butler says

    Having such a large study population, the authors of this report should continue to follow their subjects into puberty and adulthood to see if they have detectably different patterns of sexuality.

  4. Mano Singham says


    That site seems to have got its numbers from this CDC summary that quotes this paper.

    The numbers may seem puzzling initially but they are consistent.

    They found that ASD prevalence was 23.7 per 1,000 (one in 42) for boys, 5.3 per 1,000 (one in 189) for girls, and 14.7 per 1000 (one in 68) overall.

    To get the overall frequency out of 1000 for both boys and girls, you have to add the number for 500 boys (23.7/2=11.85) and the number for 500 girls (5.3/2=2.65) to get 14.5 or 1 in 69. (The very slight differences are likely due to the authors rounding off the numbers in their published paper.)

  5. Mano Singham says


    I very much expect them to do as you suggest. These massive longitudinal studies are incredibly expensive and time and labor intensive and the creators tend to milk them for all the data they can get.

  6. dmcclean says

    The slight difference probably reflects the fact that the real numbers aren’t 500 boys per 500 girls. See here for 2008 US numbers showing that there were 1050 male births per 1000 female births:

    Sorry for mixing boy/girl with male/female, but the official numbers seem to track male/female.

  7. leni says

    Wow, that is terrifying.

    Though it makes me wonder how many of those parents who won’t vaccinate due to fears of autism were able to mutilate their children’s genitals with few reservations.

  8. sailor1031 says

    Do they think that fidelity to their imaginary god is more important than the possible negative health consequences to their child?

    A rhetorical question I presume?

  9. trinioler says

    Why in the hell did you just equate autism with “negative health consequences”?

    Do you even know any autistic people?

    Do not listen to Autism Speaks. They’re an ableist hate group.

  10. autismepi says

    We have been circumcising for centuries but autism is a new and escalating phenomenon. So how could circumcision increase the risk of autism? The answer may be the use of ACETAMINOPHEN (paracetamol, Tylenol) with the procedure. This practice began in the mid 1990’s, with recommendations by WHO and the American Academy of Pediatrics. It has been shown that infants have significant difficulties metabolizing acetaminophen in the first days of life. Acetaminophen is know to have a narrow threshold of toxicity under the best of circumstances.

    Three studies investigating prenatal use of acetaminophen have found adverse neurodevelopment in the offspring- ADHD and autism phenotypes in 3 year olds. It is not such a great leap to think that acetaminophen given directly to the infant could also have detrimental effects.

  11. Vicki says

    I read “has no negative health consequences” to mean that circumcision has no health benefits, so not doing it has no health cost.

    Whereas even if a particular vaccine had unpleasant side effects in some cases, those effects would need to be balanced against the likelihood and potential harm caused by the disease. For example, I get my tetanus boosters even though they might make my arm sore, but I would prefer an otherwise-equivalent vaccine that had no chance of making my arm sore.

  12. lowspark13 says

    How did I they even get funding to do a study about this? AFAB and AMAB people (not to mention intersex people) can be autistic, but only AMAB babies have the foreskin removed after birth.

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