After this initial post, the blog will focus on specific cognitive biases, illusions, or fallacies. The next post, for example, will be on ad hoc hypotheses. But I thought I would introduce the blog with a case study that would exemplify the dangers of following intuition and instinct when making judgments. I view Unnatural Acts as an antidote to Malcolm Gladwell's Blink: The Power of Thinking Without Thinking. In Blink, Gladwell argues that intuition or quick judgments can be just as valuable as well thought out and time-consuming evaluations of data. In Unnatural Acts, I try to make the case that while intuition works well enough in many cases, for most important matters there is a much better chance of making a fair and accurate judgment by doing the hard work of collecting, analyzing, and evaluating data in an impersonal, reflective, dispassionate way. Our natural instincts work well enough most of the time, but occasionally we would be better off engaging in some unnatural acts.
Stephanie Messenger says she wrote the children's book Melanie's Marvelous Measles because vaccinations are ineffective, children should be taught to embrace childhood disease, and getting a disease like measles helps build the immune system naturally. Messenger explains her reasoning on her website Nature Matters!, which she runs out of Queensland, Australia.
She tells us that she had her first child vaccinated twice by the time he was four months old. In the U.S., the recommended vaccine schedule would include immunization against about a half dozen diseases during an infant's first four months. Messenger writes of the initial vaccination for her son:
After the first day he had almost recovered with only some irritability and restlessness noticeable. As the weeks passed he continued to reach milestones and all appeared OK.
Unfortunately, she did what comes naturally to most people: she set out to find evidence in support of what she believed. She apparently ignored the speculation of the specialists who were looking after her son that he might have a rare condition called Alexander Disease.* The unnatural thing to do is to try to falsify one's belief. Most of us don't realize how easy it is to find confirming evidence for our beliefs, but it is breathtakingly simple as long as one is selective and doesn't actively seek contrary data. When Messenger did her research, she sought evidence to confirm her belief that vaccines caused her son's seizures and eventual death. She seems to have ignored he possibility that he suffered from a genetic disorder. She had little trouble finding the confirmation she sought. She also found reinforcement from a community of like-minded people in the anti-vaccination movement. She writes:
There is ample and compelling evidence that vaccinations do work, despite what a few contrarians might argue. (See, for example, the Centers for Disease Control page on vaccines and immunizations and my anti-vaccination movement page in The
Skeptic's Dictionary.) Messenger's determination that vaccines killed her son apparently created such a negative halo effect around the concept of vaccination that she not only ignored other possibilities for her son's misfortune, she demonized the entire science-based medical community:
It saddens me to know there are thousands of babies out there being damaged, disabled or lost every year and they have no voice to stand up against the powerful drug companies and, what is now an industry, and scarcely a profession – medicine.Finding support for her belief that vaccines kill was just the beginning of Messenger's crusade. She now promotes the idea that getting diseases such as measles is a good thing for the reasons noted above, none of which have scientific evidence to support them. (Other anti-vaxxers go even further and advocate "pox parties.") Contrary to Messenger's claims, vaccinations are effective and children may die if they get a disease such as measles. Promoting diseases to build the immune systems of children "naturally" is dangerous.
According to the Institute of Child Health:
What kind of research did Messenger do? She tells the following story:
Contrary to Messenger's belief, the scientific evidence strongly supports the benefits of vaccinations. And recent tragic facts go contrary to her belief that getting diseases "naturally" is a good thing. It is good that Messenger has three healthy children, but I don't think she gives enough credit to luck for their situation. Her negative feelings about vaccination have blinded her not only to the benefits of vaccination but to the benefits of scientific medicine. While her crusade is a natural one—given the interpretation she has made of her experiences—unnatural thinking about complex issues such as the safety and value of vaccines or the cause of death of an infant are preferable if fairness and accuracy are your goals.
next: ad hoc hypotheses