By far the most prevalent popular view, particularly in the US, related to what causes autism involves vaccinations. This view of the world is supported by essentially no well supported scientific evidence. However, it is a view that is held by many vehemently and it is a view that is spreading, particularly across the internet. It is the basis for many new, unproven and potentially dangerous treatments for autism, such as chelation and the withholding of vaccines from children. This is very troubling to the scientists of the world, who I believe are doing their best within the constraints they operate to provide accurate and useful information to the public about vaccines and autism.

One of the problems facing scientists in their efforts to educate the general publis about this topic is the reality that it is extremely hard to prove a negative: i.e. that vaccines are not causing autism. The burden of evidence for a negative is vastly greater than that needed to prove a positive (such as cigarette smoking causes cancer), which is often itself hard to do to the satisfaction of society generally. While the evidence supporting this negative is growing and strong, it is still not convincing to many, particulary when the argument (logical or not) for vaccines as a cause of autism is so seductive.

On the subpages (some of which are still under construction) to this page, I have attempted to evaluate the main theories that advocate that autism is caused by vaccines. I am hopeful that I have been as unbiased as is possible. I don't have a dog in this fight. I don't have an autistic child. I don't think vaccines have done anything to me. I tend not to be generally suspicious of government or mandated healthcare for public health purposes. Probably my biggest bias is that I generally view science as an extremely positive force in our world and more likely to find truth than any other method of investigation.

Why Vaccine Theories of Autism are Highly Popular

The popularity of the various vaccine theories of autism is likely derived from many factors including the following:

- a temporal correlation between when vaccines are given (intensively during early childhood) and when autism symptoms are spotted by parents (early childhood). Some parents argue that they can tie the onset of autism to days within the first MMR vaccination  is given, which is around 14 - 18 months. However, there are many flaws to this association, including the fact that just because autism onset (at least as perceived and recalled by parents) occurs in the same temporal vicinity as vaccinations, this does not establish a causal connection between the vaccinations and autism.

- the convenience of an explanation for autism that is simple (which is very appealing) and needs no other factors: all children, at least in this country for the most part, are given vaccines, most of which are standardized. This universality of this exposure vector is very difficult to reproduce for other single vector causes like pesticides or ultrasounds.

- the lack of another good scientific explanation for the cause of autism.

- the general suspicion many citizens of this country have of government generally and government's role in mandating vaccines specifically, which is often viewed as a dramatic overreaching of power.

- a lack of understanding of the valuable role that vaccines play in protecting us from horrific diseases that ravaged populations in prior times, which compounds the suspicions people have.

- the fact that a simple explanation offers parents of autistic children a sense of control over the world; if they know what caused autism in their child, they feel they can prevent it in future children, whether theirs' or others'. This sense of control is immensely comforting

- the fact that if autism is caused by vaccines, there is an easily identifiable entity to blame for the condition of a person's child, which provides a great sense of personal relief (at least I didn't do this to my child) and a place to direct one's anger.