I have had a lot of academic instructors (I think 6) over the years mention autism in context of vaccinations. Most of the time they sound like Trump — not exactly sure what they are talking about, but there is a degree of preaching to the choir. It is very likely that they know what they are talking about and make the worst possible argument EVERY. SINGLE. TIME. I just do not really see the point in giving this spiel to students where an instructor goes full “science man” (or woman), pulls up a study, and says it is debunked.
Telling me that the dude who made the studies is a fraud or something does not do anything to actively disprove the possibility of vaccines causing autism. There is an overwhelming amount of evidence that mercury can still theoretically cause mental retardation. Something else that needs to be understood is that vaccine injuries have occurred to many internal organs, why not the brain?
A question that goes unasked and unanswered is “why can’t you sue a vaccine company if they are safe?” Answer: You get money from the government instead — vaccines have slim margins and would not be profitable if they were liable for injury. This may make you feel uneasy about them.
Null Hypothesis/Burden of Proof
When you are trying to persuade somebody to do something that they do not have to do, it is insufficient to merely say that their concerns have not been proven to be valid. The burden of proof is on you to disprove the validity of their concerns, or at least assert positive evidence.
Null hypotheses set to zero are normative in academic settings, but do not have any value in the real world outside of trials. Remember, the vaccine is not a person on trial — this whole innocent until proven guilty thing is not happening.
“It should be clear that computational convenience does not bestow credibility or epistemological priority.” —Micheal Levin
Most people, for whatever reason, claim to believe that not believing in something that does exist is worse than believing in something to be true, that is in fact, not true. Simply ask somebody if they believe in the presumption of innocence.
In practice, this is certainly not true. We do not even have definitive evidence that any of the cops that killed whatever recent African American was racist, but people believe it anyways. The statement “believe all women” is a dubious one that toes the line of presuming that the man is guilty (I suggest “all women deserve to be heard” is more appropriate).
This is hypothesis testing orthodoxy is merely projecting the belief in the presumption of innocence onto inanimate objects. Would you apply the standard of innocent until proven guilty to the safety of a car with AAA safety ratings despite countless anecdotes saying that the breaks failed on them? No but the car company is 50,000–0 in court! They are undefeated, never lost! Obviously, you should be concerned. People can game these systems and get things that they do not deserve. Drugs can be ruled safe despite not being safe (DON’T google thalidomide).
Why Vaccines Probably Do not Cause Autism
While it is impossible to empirically disprove the assertion that vaccines cause autism, it is likely that they are not related. In other words, the maximum likelihood assumption is that vaccines do not have a causal relationship with autism.
Twin studies have shown a high heritability of autism. The heritability is not what I care about as much as the phenotypic correlations. In monozygotic twins, meta analysis has shown phenotypic correlations of 0.98 (Tick et al., 2015). This is higher than intelligence.
One could argue that it is because both of the twins are likely to get the same vaccines, however, I see this as unreasonable. The problem with this argument is that the vaccine injuries are near entirely random. Just because one monozygotic twin faints after a vaccine does not guarantee that the other is going to. It is highly unlikely that autism is the only vaccine injury where the monozygotic twins show a phenotypic correlation near 1. We would have to see a lower phenotypic correlation in monozygotic twins if the vaccines were causing the autism unless vaccines were this one unique instance of a vaccines effects being an interaction that was specific to certain sets of genes.
Redefining the Autist
Once upon a time, autism was a profound mental disorder. Now the criteria is much lower. In fact, you really do not have to be all that different to be on the spectrum.
This basically sums it all up. When you look for things, you find them. The difference between autistic and neuro-typical is often small enough to the point that the label autistic really has no descriptive power anymore because if I tell you that I have autism, you are then going to ask me to describe it. When somebody says that there are 3 cars, you know that there are 3 cars.