Bad Astronomy

…but how do we recover from Jenny McCarthy?

As I mentioned, I’m no fan of Jenny McCarthy. Her antivaccination stance is totally without merit, and in fact her status as a public spokesman for that movement constitutes a public health hazard.

Let me take a moment here to say something very carefully. I am a parent. I love my daughter, and want to protect her as much as is healthy for her. I understand that instinctive need to care for a child. While I have not gone through what must be an agonizing experience for a parent of an autistic child, I’ve had my taste of such things when my own daughter was ill, or in an accident.

Talking about kids with autism is a topic filled with emotion. Any time a topic invokes a strong emotional response, critical thinking is the first victim. People are less likely to listen to hard evidence and more willing to accept anecdotal evidence – that is, stories that support their pre-existing beliefs, even if those beliefs are completely wrong. Ms. McCarthy and the antivaxxers have lots of anecdotes, but the real evidence is totally against them. Remember, as hard as it is to talk about this, the ramifications are very, very real: outbreaks of diseases are on the rise because antivaxxers are scaring people into not vaccinating their children.

So we must talk about this.

Ms. McCarthy has an autistic son. Or, according to her, he was autistic; now she’s claiming her son has been cured of autism. She makes this claim in an Us magazine interview, saying changing his diet by removing wheat and dairy products has cured him. In this puff piece, there is not a single medical person contacted (just a general statement saying “doctors have accused her of creating fear of necessary vaccines”), not a single mention that there is no evidence of a relationship between vaccines and autism and in fact strong evidence against such a relationship, and not a single statement that McCarthy might be wrong – actually, is certainly wrong – about vaccination.

In fact, they didn’t even ask her if a doctor had corroborated her diagnosis that her son is cured.

I am not accusing Ms. McCarthy of lying; in fact I think she is a caring parent who loves her son, but who has taken the decidedly wrong path of science denial. But I am very curious about her saying her son was cured. While the press (in the form of Us magazine) has been positive over this, it has not been at all investigative of her claims. We have not seen any diagnoses of her son, for example. Again, I am not accusing her of lying, but let’s bear in mind the seriousness of her claim: she is saying her son is no longer autistic, and that she cured him by changing his diet.

This is a incredibly serious claim, and she is the one using it not only as a weapon against vaccination, but also is de facto telling others to ignore medical advice and try this “alternative” therapy. The burden is therefore on her to show the evidence for her claims. This is absolutely essential: I expect the antivax movement will trumpet her claims loudly and often. But how much real evidence can be made to back up Ms. McCarthy’s claim? For example, there is a broad spectrum of autism disorders, and some research indicates children can do better naturally as they age. Could this be the case here?

I suspect very strongly that what Ms. McCarthy is engaging in is a mistaken way of thinking called post hoc ergo propter hoc: because an event happens after something, it happened because of that thing. Her son got autism after a vaccination, therefore he is autistic because of the vaccination. But vaccinations are given around the same time children can be first diagnosed with autism! So it makes a link, a false link in a parent’s mind. Again, doctors have made very careful studies of this, and there is no link between vaccines and the onset of autism.

And now she is propter hoccing again. Let’s assume her son really is doing better. This happened after she changed his diet, so in her mind it happened because of the diet. But it also happened after we invaded Iraq, and after Cassini reached Saturn, and after I left my last job. None of those things were related to her son’s illness, just as his diet almost certainly wasn’t either. And remember, it’s possible that his alleviation of autism symptoms was a natural aspect of his getting older.

I rail against uncritical thinking on this blog and in everything I do in life. The Moon Hoax, the Face on Mars, and other things like them may not have much of an impact in “real” life, but the same lack of critical thinking skills does affect us, all of us, especially when a celebrity with some notoriety is the one behind them, aided by an all-too-willing and credulous press.

Vaccines are one of the greatest triumphs of medical science. Children can die from not getting vaccines. There is no evidence vaccines cause autism. Jenny McCarthy is wrong.

If you have questions on this, talk to your doctor. Do your research. But please, please, don’t just listen to what McCarthy says, or any of the antivaxxers. They’re dead wrong on this.