Vaccines, Autism, and the Promotion of Irrelevant Research: A Science-Pseudoscience Analysis

Proponents of the vaccination-autism link have created a bogus scientific debate by providing lists of studies that supposedly support their claims. In actuality, these studies are typically questionable or irrelevant. We identify this as its own developing pseudoscientific tactic: the promotion of irrelevant research.

CRAIG A. FOSTER and SARENNA M. ORTIZ

Larry Kusche’s review of the Bermuda Triangle mystery (1986; 2015) provided one of the clearest victories for reason over rumor. His method remains convincing because it was so straightforward. Kusche demonstrated that many disappearances had been wrongly attributed to the Bermuda Triangle; the actual events either did not happen as reported or likely occurred outside of the infamous area. Kusche also demonstrated that the rate of actual disappearances within the triangle did not seem to differ meaningfully from the rate of disappearances in other parts of the ocean. In so doing, Kusche highlighted two issues that occur frequently in pseudoscience. The first involves reporting events inaccurately, and the second involves relying on handpicked observations rather than a representative set of observations (Hansson 2013).

Vaccinations and Autism: Inaccuracies and Anecdotes

Much of the debate surrounding vaccines and autism has been similarly based on straightforward considerations about whether the reported evidence is accurate and whether a representative set of evidence supports the vaccines-cause-autism claim. This debate was triggered by Andrew Wakefield and others’ (1998—Retracted) research involving twelve children who were referred to a pediatric gastroenterology unit. Wake-field et al. reported that all twelve children had experienced developmental problems at varying intervals after exposure to the measles, mumps, and rubella (MMR) vaccine; nine of these developmental disorders were identified as autism with a tenth being questionably identified as autism. Wakefield et al. used these results to suggest that the MMR vaccine could contribute to a syndrome involving gastrointestinal problems and regressive autism. This research fueled the well-known concern about childhood vaccination and its alleged contribution to autism—a genie that shows no sign of returning to its bottle.

Even if the Wakefield et al. results had been legitimate, the small sample size and selective nature of the sample should have encouraged a cautious interpretation. Nevertheless, the evidence was at least broadly interpretable: a small group of children received the MMR vaccine and subsequently experienced developmental problems. Of course, this evidence was not accurate. Wakefield created fraudulent results presumably for financial reasons (Deer 2011). Subsequent research revealed no evidence that childhood vaccine administration elevated the rate of developing autism (Taylor et al. 2014). In the absence of any scientific connection between vaccinations and autism, promoters of the vaccines-autism link could still handpick observations. Anti-vaccination proponents pointed to the many vaccinated children who later developed autism (noted by The Logic of Science 2016). The best-known example has probably been actress Jenny McCarthy’s son. In a strange twist, some have raised the possibility that McCarthy’s son did not actually develop autism (Rubin 2008).

We view the handpicking of confirmatory observations with understanding. It is natural for humans to seek explanations for difficult events, and the temporal proximity between a vaccination and the diagnosis of autism could certainly feel causal. Nevertheless, this aggregation of anecdotes, no matter how broad, is not science. Most objective observers can understand that if millions of children are vaccinated and a fraction of children develop autism, then many children who have been vaccinated will subsequently develop autism, even in the complete absence of any cause-effect link. Obviously, many people still believe that vaccinations cause autism, but at least the science and pseudoscience surrounding this debate remains relatively clear. The scientifically minded can point to the absence of any correlation between childhood vaccination and the development of autism. Proponents of the vaccines-autism link can point to the number of children who were vaccinated and later developed autism.