You want to inject me with vaccines and then dissect my brain? Why? We already know vaccines don’t cause autism!
Having written about pseudoscience and quackery continuously for over a decade and having engaged in conversations about it online for over 15 years, I’ve come to recognize a number of traits that are virtually the sine qua non of quacks and pseudoscientists and their believers. Obviously, one of them is a severe case of the Dunning-Kruger effect, a tendency of those with low expertise in a topic to overestimate their expertise and express far more confidence in their conclusions than warranted while those with high expertise know enough to know how much they don’t know about a topic and thus tend to express more uncertainty and caveats. Basically, the Dunning-Kruger effect describes how unskilled individuals express an illusory superiority, mistakenly believing their knowledge, competence, and ability to be much higher than it really is.
As a result of the Dunning-Kruger effect, coupled with other cognitive shortcomings suffered by all human beings (but seemingly amplified in believers in quackery and pseudoscience) that lead them to believe in pseudoscience, such as confusing correlation with causation, motivated reasoning, and the like, believers in pseudoscience are often so absolutely rock-solid in their beliefs that they are virtually impossible to reason with. It is incredibly difficult to change their minds, and disconfirming evidence often causes them to dig in all the more deeply to defend their beliefs. Not uncommonly, this leads them to commission studies designed to support their beliefs. But what happens when such a study does not actually support their belief? What happens when such a study backfires spectacularly and not only fails to support their belief, but emphatically so? Skeptics were re-treated to just such a spectacle last week when SafeMinds and other antivaccinationists were burned by a study they funded (subscription required):
Between 2003 and 2013, SafeMinds provided scientists from the University of Texas Southwestern School of Medicine, the University of Washington, the Johnson Center for Child Health & Development and other research institutions with approximately $250,000 to conduct a long-term investigation evaluating behavioral and brain changes of baby rhesus macaques that were administered a standard course of childhood vaccines. (The National Autism Association, another organization that has questioned vaccine safety, also provided financial support for this research.) The latest paper in the multiyear project was published Monday in the Proceedings of the National Academy of Sciences (PNAS). In it, the researchers concluded that vaccines did not cause any brain or behavioral changes in the primates.
Astute readers will recognize that I’ve written about similar papers before reporting that pediatric vaccines cause changes in behavior and/or brain structure in macaque monkeys. Specifically, way back in 2008, I noted the initial report of this ongoing study, first when preliminary results were reported as a poster presentation and then later another publication from the same group published in 2009. Steve Novella and a certain well-known friend of the blog have also described how poor experiments published from these studies in 2010 were, the latter of whom cited several other major criticisms of the study, not the least of which was some reporting of changes in the size of a part of the brain known as the amygdala that were…hard to believe. There were also a lot of issues with the control group chosen.
Basically, these abstracts and papers reported the results of an ongoing study looking at infant vaccines in macaque monkeys to see if there was an effect on socialization or changes in brain anatomy, the key hypothesis seeming to be that thimerosal-containing vaccines cause autism. (The investigators even added thimerosal to some of the vaccines because they weren’t being made with thimerosal anymore!) You can read the links I cited just now if you want the gory details; suffice to say that these were not good studies and not particularly good evidence that vaccines cause autism, as shown by the fact that homeopaths loved the study, and ultimately the paper examining hepatitis B specifically was withdrawn. Yet these reports were flogged for quite a while by the antivaccine movement as proof positive primate data that vaccines are Evil.
Fast forward to 2015. Now we have a much larger, much better study. It’s even by the same people. And guess what? It’s as negative as negative can be. No wonder SafeMinds and other antivaccinationists are unhappy. Let’s take a look. (more…)