Saturday, February 14, 2009

Are Autistics More or Less Likely To Commit Murder?

I'm sure many readers must have heard about the case of Sky Walker, an autistic teenager who has allegedly murdered his mother.

As you might expect, some people are using this case to support their views about autism. Kim Stagliano, for example, apparently argues that treatment is both necessary and effective in preventing this sort of circumstance. Plausible as her argument may sound to many, she has not presented any data to support it that I know of.

Harold Doherty has written about the case, trying to connect it to awareness of self-injury. Interestingly, Harold Doherty had been recently arguing that Andrew Wakefield should not be considered guilty until he is convicted by a tribunal of some sort. Harold has not expressed the same reservations about the media treatment of the Sky Walker case.

I'm not going to talk about the philosophical implications of the case, or possible root causes, etc. Others would be much better at doing that. What I will do is see if we can confirm or reject the hypothesis that autistics commit murder more (or less) often than non-autistics.

As you can imagine, there's no published data on the rate of murders committed by autistics. So do we give up and say we just don't know?

Let us first determine if autistics are more or less likely to murder than to be murdered. (I realize it's not the same question, but I think it's an important preliminary question we should try to answer.)

Consider this. The number of non-autistics who commit murder is roughly the same as the number of non-autistics who are murdered. If you discount mass murders and conspiracy murders, this is roughly correct. Is the same true of autistics?

I will assume that both murders of autistics and murders committed by autistics are reported in the media with good and fairly equivalent frequency. I contend this is a reasonable assumption, though I admit I could be wrong.

I carried out a Google News archive search of "autism murder" between 2008 and 2009. I'll just go over the first 3 pages of the search results (as I don't intend to spend days on this.) These are the persons accused of murder mentioned in the stories:

  • Karen McCarron (non-autistic)
  • Flower Nicole Tompson (non-autistic)
  • Robert Napper (autistic)
  • Xuan (Linda) Peng (non-autistic)
  • John Odgren (autistic)
  • A schoolboy (non-autistic)
  • Allen Grabe (non-autistic)
  • Judith Leekin (non-autistic)
  • Andrew Reid Lackey (autistic)
  • Unnamed boy (autistic)

That's 6 non-autistics and 4 autistics who have been accused of murder according to the set of stories that was examined. It's close. I'd say we can't reject the null hypothesis here, but it's possible that autistics are slightly more likely to be murdered than to murder.

An obvious counter-point is that the carers of autistics might be more prone to murder than non-autistics in the general population, so the comparison does not tell us whether autistics are less violent than non-autistics, only that we are equally or less violent than non-autistic carers of autistics. However, if it is true that the stress related to caring for an autistic person tends to increase the murder rate by carers, wouldn't the same hold true about the stress experienced by the autistic persons who are cared for?

Let's try to estimate what the rate of murder by autistics should be in the US, if autistics were just as prone to committing murder as non-autistics. There were 16,929 murders in the US in 2007 [source]. Using a conservative estimate of murderers who should be autistic (50 in 10,000), it would seem that about 85 murders should have been committed by autistics in 2007, by chance alone, without assuming autistics are more prone to murder.

Clearly, 85 murders by autistics were not reported in the media in 2007, otherwise you'd see daily blog posts about it from people like Harold Doherty, John Best and Kim Stagliano. One probable reason why we don't see those reports is that autism is more than likely underrecognized in adults. Is it possible autistics are less prone to murder than non-autistics? I wouldn't rule it out, but we just don't have enough evidence to say this.


There is simply no evidence that autistics are more prone to committing murder than non-autistics. Such views are only supported by anecdotes and socially constructed notions of autistic characteristics. A cursory look at available reports in the media does not support the claim that autistics are more violent than non-autistics.


  1. J,

    Even if it was found that we are, overall, more likely to be involved in interpersonal violence - given the amount and degree of abuse, harassment and bullying we suffer, it still wouldn't mean we're more dangerous than NT's.

    As for Harold, he's sat a the back of the class with JB. It'd be best if we all just ignored him.

  2. "Harold has not expressed the same reservations about the media treatment of the Sky Walker case."

    That's because Harold L. Doherty is - as he has managed to demonstrate so ably - basically a two-faced piece of shit.

  3. I agree with your assessment, Socrates.

    BTW, my 6:4 ratio finding is actually biased against autistics. Here's why.

    There will be cases of undiagnosed autistics who are murdered and undiagnosed autistics who commit murder, which wouldn't show up in the media.

    However, you will note there are cases of people accused of murder who are apparently found to be autistic after they are accused. This is probably quite common and incentivized by insanity pleas.

    The same thing wouldn't happen to undiagnosed autistics who are murdered. That is, it's unlikely that a psychiatrist will show up after someone is murdered to try to determine if they are autistic.

    Therefore, newspapers will tend to overreport murders committed by autistics compared to murders of autistics.

    That would also tend to compensate for the fact that autism is underrecognized in adults.

  4. Excellent post! "

    Such views are only supported by anecdotes and socially constructed notions of autistic characteristics"

    I think also that the way how autism is defined as a different type of disorder from other developmental disorders, psych disorders, etc. (which leads to it having such dangerous treatments), there is more potential for worse consequences for the bogus claim.

    I hope people start reconsidering the dangers of encouraging this myth.

  5. Fascinating post. I'd looked at what I consider to be a broadly similar topic some time ago - whether the mentally ill were as dangerous as the media stereotypes suggest (in response to stories in the mainstream media that made it sound like schizophrenics were a terrible danger to our otherwise safe community).
    Here, the BBC have news of a report from the IoP ["Murders committed by mentally ill people are not on the increase, despite popular belief"].
    Here, there's a paper that claims to help "dispel the myth that the mentally ill constitute a dangerous group prone to violent crime."
    There's also a post on Bad Science about a paper showing that (to quote Ben Goldacre) "murders by people with serious mental illnesses, despite the hype and the fear, the public pronouncements and the headlines, have come down massively since the 1970s, to fewer than 20 a year today."

  6. Thanks jdc325. I wasn't really aware of those findings, but they confirm what I suspected.

  7. Intesting subject,
    Last week I published a video blog on Autism and Prejudice. It was related to the murder of Dutch Politician Pim Fortuyn and the prejudice about People with autism and Murder.

    His killer, Volkert v.d. G. was described by the media as possibly Aspergers.

    Good blog!

  8. The Autism Society of America studied the crime statistics a few years ago. They found that out of almost 1.5 million violent crimes per year in the United States, only 4.5 people per year assert autism as a defense in a violent crime case.

    As you point out, some violent criminals may be autistic and not know it; but we're still talking about a very small number.

  9. In that case, I stand correct about there no being published data. Do you have a link, Abfh?

    I suspect the number of cases where autism is cited as a defense has increased since then, though.

  10. I don't recall where the published data was posted, but this article by Kristina has a reference to it.

  11. Cho Chin Chew2/18/2009 8:50 PM

    This comment has been removed by a blog administrator.

  12. Joseph,

    You may wish to check the IP on the post by Cho Chin Chew. We know who that is!

  13. If your intention is to invoke body counts to excuse any murder whether Aspie murder of NT's or NT's murder of Aspie's, I give you Adolph Hitler whose body count is close to 50 million. Michael Fitgerald, a so-called 'Autism expert' has retrospectively diagnosed Hitler with Asperger Syndrome:

    "Michael Fitzgerald, an expert in autism spectrum disorders, concludes that Hitler suffered from, and met all the criteria of Asperger syndrome as documented by Hans Asperger. As evidence of possible Asperger's, Fitzgerald cites Hitler's poor sleep patterns, food fads, dislike of physical contact, inability to forge genuine friendships, and an emptiness in his human relations. His conversations in the Men’s Home in Vienna were really harangues and invited no reciprocity, for which he seemingly lacked capacity. In Munich, Hitler was distant, self-contained, withdrawn and without friends. His comrades noted that he had no humanitarian feelings, that he was single-minded and inflexible. He was obsessive and rarely made good or interesting company, except in the eyes of those who shared his obsessions or those in awe of, or dependent on him".

    The ND crowd is always eager to welcome well regarded historical figures into their 'community' but run away when Hitler is described by an 'autism expert' as one of their community. Fitzgerald is the same author who recently diagnosed Charles Darwin as being 'autistic' and previously well regarded historical figures such as Einstein, Wittgenstein, Newton, but also Adolpf Hitler. Welcome to the ND pantheon of heroes Adolph.

  14. Raj, please go and masturbate elsewhere. You have nothing to contribute here.

  15. RAJ's comment is completely irrelevant to the question at hand.

    RAJ, come back when I write a post titled, "Are autistics more likely to be brutal dictators?"

  16. "RAJ, come back when I write a post titled, "Are autistics more likely to be brutal dictators?"

    The answer to your question is yes Aspies are more likely to be brutal diactators and mass killers ( Adolph Hitler). Just ask Mike Fitzgerald who has made a career of diagnosing the dead. OTOH I don't want to see you or Socrates, both self-diagnosed Aspies embracing any of the well beloved historical figures without accepting Hitler as one of your own.

    Intersting discussion, so far the body count in this discussion is Aspies murdering NT's 50,000,004.. NT's murdering Aspies 6.

  17. RAJ over the last two years your contributions to the "Debate" have degenerated to the point of obscenity.

    I've archived your post below for future reference.

  18. RAJ, what exactly makes you think that either Socrates or I would deny Hitler is autistic, if he in fact is shown to be?

    Has any of us analyzed Mike Fitzgerald's diagnoses of historical figures? I haven't even read his papers about it, to tell you the truth.

    Your clever comparison at the end has an obvious flaw, BTW, in that you're comparing Hitler's body count to murders of autistics reported only in 2008.

    But that doesn't matter either way, because the question is about the social problem of murder, not about all types of killing like killing by proxy that occurs in war time. If you will, I could rephrase it as follows: In times of peace, are autistics more likely to commit murder than non-autistics?

    Furthermore, it's obvious that there have been brutal dictators who are non-autistic.

    Finally, I don't know about Socrates, but you're making a presumption about me being self-diagnosed. I've talked about this before. While I don't have a need for "official papers," I'm not exactly self-diagnosed.

    You can obviously use "self diagnosed" as a label that sounds dubious, as many others do, but can you produce evidence that self-diagnoses of ASD are unreliable? Let's see the evidence.

  19. RAJ: "The answer to your question is yes Aspies are more likely to be brutal diactators and mass killers (Adolph Hitler)."

    Are you serious, RAJ? I mean, really? On the basis of ONE possible case, you make the claim of more likely???

    That is just ridiculous!

  20. Southeast and main Asian pandora jewelry countries have twisted rubies for centuries, cheap pandora bracelets but research as to where, and how to find more deposits is Pandora charms spare, and production has figured out how and mining companies,” Pandora beads Giuliani says, to look at exactly the right time and place.” pandora set Farther investigation of claret formation, based on tectonic scenery, cheap pandora geochemistry, fluid inclusions and isotopic ratios, allowed discount pandora Giuliani’s lineup to remodel a new prototype for the French Institute pandora 2010 of Research for Development (IRD) and the National Scientific pandora sale Center of Research, two government-sponsored knowledge Pandora Bangles and technology research institutes that aim to aid in the sustainable cheap pandora bracelets development of developing countries. Before the collision pandora bracelets prices of the Eurasian and Indian plates, lagoons or deltas sat in the regions where marble is giant, pandora bracelets and charms he says, “and there is the brains to expect that the new pandora bracelets sale thoughts should help development of the artless capital.” discount pandora bracelets Virginie Garnier, Gaston Giuliani and Daniel Pandora necklace Ohnenstetter urban the shape to do just that. They work for the garnet cheap pandora charms genesis. While studying the bedrock in Vietnam in 1998, the discount pandora charms French players found rubies, which detained traces of aluminum, chromium pandora charms sale and vanadium from universities, international corporations, governments pandora charms 2010 and why the rubies got there, and has created a paradigm Pandora beads to help these evaporites, Garnier says, when the Eurasian cheap pandora beads and Indian plates collided, raising the Himalaya Mountains.