The Atlantic has a new article on how people get drawn into the anti-vaccine movement. Ultimately, the reason why many parents end up opposing vaccinating their own children seems to be that people are terrible at judging risk in a rational manner. The parents end up weighing the generally rare threat of dangerous disease against the even more rare but also more immediate threat of vaccine complications and decide that the minuscule threat from the vaccine is more dangerous. A more rational result would be that while the threat of disease is low, it is generally higher than any threats from the vaccine. Additionally, the only reason why the threat of disease is low is that nearly everyone is vaccinated, preventing many dangerous illnesses from spreading throughout the population. While one child not getting vaccinated does not change this, too many children going unvaccinated could allow for diseases such as measles and whooping cough to return. This has already been happening in a number of places. With the vaccination program, society has decided to accept a very small number of serious complications in order to prevent a much worse outcome from allowing these diseases to spread.
The article highlights the fact that many people place more weight on personal anecdotes than actual evidence (i.e. blinded studies using statistical analysis). In the words of one parent “data could be flawed … but someone’s story … I trust that more.” Obviously, data could be flawed, but scientific studies have at least attempted to remove biases and will almost always be better than talking to some non-random sample of people (by construction a flawed dataset). There’s even a doctor who uncritically accepts his patients’ beliefs about what caused their children’s medical problems as evidence that vaccines are dangerous. Doctors are supposed to listen to their patients, but also need to correct patients when they make unfounded claims. Just because someone says a vaccine hurt their child doesn’t make it true. It doesn’t make it untrue either, but the number of people claiming to have encountered vaccine complications is vastly higher than what would be expected from the scientific literature.
The article does a decent job of juxtaposing the arguments of the people opposing vaccines against some of the reasons why their views are (if we take the most charitable explanation of their views) misinformed. Too often the media prefers to frame every controversy as a debate between two equal sides when in many cases there is only one side with any significant supporting evidence.