My chiropractor told me I don’t have the gene for autism, so it must have been caused by something else, probably vaccines.
I blame hair conditioner. Widespread use of hair conditioner began in the seventies, shortly before the alarming rise in diagnoses of autism. Well, what do you expect, rubbing chemicals into your head? Even now, places where hair conditioner is not used have a far lower reported incidence of autism. The more hair conditioner a population uses, the higher the rate of autism diagnosis in that community.
Well, no. I don’t really think autism is caused by hair conditioner, though that correlation does exist.
This is the kind of argument frequently used by anti-vaccination campaigners; this happened, then that happened, so this must have caused that. My child was vaccinated, then I noticed his ears turning purple. That had never happened before. Big pharma is trying to poison us!
This kind of faulty reasoning is so old and so common it has a name; post hoc ergo propter hoc. After this therefore because of this. The ancient Greeks and Romans knew this did not necessarily follow over two thousand years ago.
But anti-vaxxers still manage to fool some people, potentially endangering themselves, their children, and others.
A couple of years ago in a doctors office in Perth, a nurse was drawing down a vaccine to administer to a four year old girl. The child began having convulsions while she was waiting with her mother. If her convulsions had started just a few minutes later, medical staff would never have been able to convince her parents they were not caused by the vaccine.
Just because something happens after something else does not mean the first thing caused the second.