Autism is viewed by science as one of the most genetically determined mental disorders, with between 80% and 90% of the variation in who gets autism determined by genetics. For instance, siblings of a person with autism are dramatically more likely to develop autism than an unrelated individual – sibling rates of autism are 20 to 40 times higher than that of non related children. Autism tends to travel in families from generation to generation. Family members of autistic individuals often have abnormally frequent characteristics reminiscent of autism, such as hermitism / social withdrawal / abnormal introversion and extreme systematizing (i.e. occupation as mathematicians and scientists). And, families with high rates of other mental disorders such as bipolar disorder and anxiety disorder have higher rates of autism.

Moreover, the ‘vaccines as the cause of autism’ theory misses the whole neurodiversity concept (the idea that evolution conserved many different personality types, even some that result in frequent disorders). Persons with autism do not just have deficiencies and problems. Particularly on the higher functioning side of autism, there are areas of tremendous and unique competency in autism, from systematizing to spatial processing to problem solving. These heightened abilities were almost certainly part of the reason persons who tend to develop autism were conserved evolutionarily. And, you don’t have to be disordered with autism to share these areas of heightened competency.

There are many individuals (including myself) who are not autistic (don’t reach a level of dysfunction to get a diagnosis), who often share what are perceived to be autistic weaknesses (poor social awareness, a tendency towards social withdrawal) but who play very important roles in society (engineers, scientists, computer programmers) as a result of their unique skills due to their genetic heritage. And, these character traits tend to travel across generations. Postulating that vaccines cause all or even a substantial fraction of autism cases completely ignores this reality. Rarely does a disease or toxic exposure result in enhanced competency. The effects are almost always negative because they knock the organism out of homeostatic balance, resulting in disease.

The concept that vaccines are dominantly involved in autism causation does not make a lot of sense in light of the clear genetic contribution to autism, certainly at the extreme end of the vaccine / autism theory (i.e. autism being a unique form of mercury poisoning). Environmental factors are absolutely involved in autism (i.e. fetal alcohol exposure and prenatal encephalitis exposure). In my opinion, they are more important than is acknowledged by science because science is essentially incapable of ascertaining when multiple environmental factors are working together towards an outcome. However, they are only a participant in the underlying causation of autism, not the dominant player. And, while this particular analysis on genetics can not eliminate vaccines from having a role in autism, it can provide a strong case that any role vaccines play (along with most other potential environmental causes) is contributory at best.