What is a greater threat to public health, infectious disease or autism?
Former Playboy model Jenny McCarthy and erstwhile pet detective Jim Carrey would rather your child die from infectious disease than have autism. (This even though Ms. McCarthy’s son was “cured” of the disorder.) Mr. Carrey wrote a column for the Huffington Post yesterday demanding more studies of vaccine safety and ignoring scientific and logical evidence concluding vaccinations do not cause autism. This position has very real consequences for public health. The more unvaccinated people there are, the more likely an epidemic is to occur. It’s not just a personal choice whether to protect yourself and your family or not, either. No vaccine is 100% effective, so an unvaccinated person puts even vaccinated persons at risk.
To help explain this irrational and downright dangerous behavior, I turn to an article by my personal security hero Bruce Schneier. In the context of the Conficker computer virus, Schneier discusses how humans deal with threats, information, and probability in general:
Generally, our brains aren’t very good at probability and risk analysis. We tend to use cognitive shortcuts instead of thoughtful analysis. This worked fine for the simple risks we encountered throughout most of our species’ existence, but it’s much less effective against the complex risks society forces us to face today.
For example, we tend to judge the probability of something happening based on how easy it is to bring examples of that thing to mind. It’s why people tend to buy earthquake insurance after an earthquake, although in reality that’s when the risk is the lowest. It’s why those of us who have been the victims of a crime tend to fear crime more than those who haven’t. And it’s why we fear a repeat of 9/11 more than we fear other types of terrorism.
We fear being murdered, kidnapped, raped, and assaulted by strangers, when friends and relatives are far more likely to do those things to us. We worry about airplane crashes instead of automobile crashes, which are far more common. In general, we tend to exaggerate spectacular, strange, and rare events, and downplay more ordinary, familiar, and common ones.
We also respond more to personal stories than to data. If I show you statistics on the crime rate in New York, you’ll probably shrug and continue your vacation planning. But if a close friend gets mugged on a trip there, you’re much more likely to cancel your trip.
And specific stories are more convincing than general ones. That is why we buy more insurance against airplane accidents than we do against travel accidents, or accidents in general. Or why, when surveyed, we are willing to pay more for airline travel insurance covering “terrorist acts” than “all possible causes.” That is why, in experiments, people judge specific scenarios as more likely than more general scenarios, even if the general ones include the specific.
McCarthy and Carrey probably don’t remember their friends dying of vaccine-preventable diseases when they were children because vaccines protected them. They remember their child’s diagnosis with autism quite vividly. These crusaders are even unapolagetic about the return of measles. As Ms. McCarthy so eloquently put it, “If you ask a parent of an autistic child if they want the measles or the autism, we will stand in line for the f___ing measles.”
Indeed, they are replacing a general threat with an unlikely, illogical specific one. Measles infected nearly 4 million people, chronically disabled 1,000, and killed nearly 500 a year before the vaccination program was introduced. It remains a top killer of children under five around the world. Influenza still causes more deaths a year than measles ever did, around 36,000 flu-related deaths occur each year. Most of those individuals were not vaccinated against the flu for whatever reason. According to the Autism Society of America only 1.5 million Americans total are living with autism and related disorders.
We do not know yet what causes autism. While tragic for parents and families at first, it remains non-fatal. On the other hand, we do know what causes numerous, potentially fatal infectious diseases. We know how to prevent these deaths, too. Vaccines.
Given people’s tendency to take anecdotal evidence more seriously than real evidence, I would respectfully request that Mr. Carrey go back to making his butt talk rather than pulling information out of, and talking from, it.
-Michael E. van Landingham