What is the most harmful pseudo-science?
Published: February 4, 2015
This question is rather subjective and depends on what you mean by "harmful". If you mean to ask which pseudo-science concept leads to the most bodily harm to humans, then the winner is definitely vaccine denialism. The safety and effectiveness of vaccines in protecting humans against specific diseases is one of the most experimentally-verified concepts of all time. Believing that the moon landings were faked may make you out of touch with reality, but this belief does not really harm anyone. In contrast, avoiding vaccines ultimately leads to disease and death. Furthermore, avoiding vaccines not only harms you, it harms your entire community because you spread dangerous contagions once infected. This fact is what makes vaccine denialism so insidious. No matter how trendy, popular, "natural", and attractive vaccine avoidance is made to appear, it does not change the scientific fact that vaccines save lives in a measurable, understandable, direct manner; and that vaccine denialism leads to disease, suffering, and death. Among all the different kinds of pseudo-science, vaccine denialism stands alone in a separate category because of the ability of viruses and bacteria to spread and mutate. Let's look at what makes vaccine denialism stand in a league of its own among the pseudo-science concepts.
1. Vaccine denialism leads the denialist to fail to protect himself from serious diseases.
Believing that free energy devices actually work will lead you to waste a few dollars on a useless electric gizmo but will not do much else. Using a magnetic health bracelet may not improve your blood flow, but it also won't hurt you. Believing that distant stars uniquely affect your personal relationships may cause you to make poor relationship decisions, but the belief won't cause you bodily harm. Believing that aliens from another planet have landed their UFO's on earth may lead to some awkward conversations at social events, but it won't cause anybody to get sick or injured. In contrast, avoiding vaccines ultimately leads to increased infection and bodily damage. Often when educated people meet a friend who believes in some form of pseudo-science, our response is to roll our eyes and change the subject, mumbling to ourselves, "Whatever. He is free to believe this nonsense. It doesn't hurt anyone." But when it comes to vaccine denialism, it does hurt people. Educated people therefore have a moral obligation to speak up against vaccine denialism.
Note that we should make a distinction between unknown science and pseudo-science. An instance of unknown science is a certain claim that has no experimental evidence supporting it but also no experimental evidence disproving it. For instance, scientists don't actually know what exists at the center of a black hole. Therefore, even though the belief that black holes contain ice cores may ultimately turn out to be incorrect, it is a perfectly reasonable and rational belief since there is no experimental evidence to disprove it. Such is the nature of unknown science. In contrast, an instance of pseudo-science is a certain claim that has ample experimental evidence disproving it. Belief in pseudo-science is therefore irrational since it requires the denial of physical reality. Vaccine denialism is the ultimate example of pseudo-science, since there is an unparalleled amount of evidence proving that vaccines are generally safe and effective. Every time one person receives a vaccine and is thereby protected from disease, that person becomes one more successful repetition of the vaccine experiment. Since billions of people have been vaccinated and protected over the last two hundred years, the effectiveness of vaccines is one of the most experimentally-verified concepts of all time.
2. Vaccine denialism is indisputably harmful.
Historical records spanning back 200 years, such as reported in the Social History of Medicine journal, make it clear that every time a community of people avoids vaccines, outbreaks of preventable diseases occur. We are not talking about winter colds here. We are talking about serious diseases such as measles and polio; diseases which can cause death and permanent disability. In 1980, before widespread vaccination, measles killed 2.6 million people a year globally according to the World Health Organization. In contrast, after years of widespread vaccination, measles killed 146 thousand people globally in 2013. Most of these deaths did not occur in regions of the world with high vaccination rates. For instance, the United States experienced zero deaths due to measles in the first eight months of 2013. Vaccine denialism leading to outbreaks of preventable disease is nothing new. Historical records show this phenomenon occurring repeatedly, stretching back over a hundred years. Sadly, some people fail to learn from history, have no knowledge of history, or actively deny history.
Vaccines are in an entirely different political category from the category that economic and social issues belong to. Whether a national tax break should be passed is a difficult question. The answer to this question depends on whether the majority of citizens value high personal incomes more, or whether they value government services more. Furthermore, there is no hard scientific evidence identifying one option as better. In this way, political debates about economic and social issues are largely driven by ideology, personal opinion, and political party tribalism. In contrast, there is indisputable scientific evidence that vaccines prevent serious harm. Therefore, there is not really a valid political debate about vaccines, since the evidence is all on one side. Politicians who promote vaccine denialism are not furthering a rational debate, since science settled this question long ago. Such politicians are instead displaying either scientific illiteracy or an intentional denial of reality. In either case, such politicians are not fit for office since vaccine denialism causes so much harm. When a person inserts vaccine denialism into a political discussion, you can be sure that rational discussion has ended and blind ideology has begun.
3. Vaccine denialism harms multiple people and not just the vaccine denialist.
Viral and bacterial infections are contagious. A person who becomes infected with a preventable contagious disease becomes a host from which the disease can be spread to others. As infected people sit at school, chat at work, ride the subway, attend sports events, grab snacks at shops, and enjoy rides at amusement parks, they are spreading contagions everywhere they go and endangering everyone they come close to. A vaccine denialist with measles will spread measles to the other vaccine denialists in his neighborhood, since they are similarly unprotected. Furthermore, he will also spread measles to the general public. How is this possible if vaccines are effective? There are four different mechanisms that make this possible.
First, no vaccine is 100% effective. Most vaccines are typically 80% to 99% effective, meaning that if 100 people get vaccinated, only 80 to 99 of those people are actually protected. Therefore, infected vaccine denialists will spread the disease to the 1% to 19% of the vaccinated population that is not effectively protected by their vaccinations. Second, viruses and bacteria that are thriving in an infected host have a chance to mutate. If they mutate enough they will not be stopped by vaccinations. If sufficient mutation occurs, the infected vaccine denialist puts 100% of the vaccinated population at risk. Third, young babies are not yet physically ready to receive all of their vaccinations. Even if the baby belongs to a pro-vaccination family, simply the state of being too young for full vaccination makes the baby potentially unprotected to the disease being spread by the infected vaccine denialist. Fourth, some people have malfunctioning immune systems and are unable to receive vaccinations or receive any benefit from them, even if they wanted to. In these four ways, vaccine denialism causes preventable disease to be spread through the general population. Vaccine denialism harms multiple people and not just the vaccine denialist.
This last point is what makes vaccine denialism so serious. When a person chooses to avoid vaccines, he chooses not only to potentially harm himself, he also chooses to potentially harm all those he comes in contact with, and all the people that those people come in contact with, and so on. When a person chooses to not wear his seat belt while driving, he is only putting himself at risk. When a person chooses to avoid vaccines, he is putting his whole community at risk. Vaccine denialism is not like one person deciding to not wear his seat belt. It is more like one random person forcing a large segment of his community to not wear their seat belts, despite their desires otherwise. As another metaphor, vaccine denialism is not like one person smoking a cigarette in his own home. Although smoking has been firmly established to be harmful to your health, it is still legal based on grounds of personal liberty since it harms no one else. In contrast, vaccine denialism is more like one random person forcing a large segment of his community to smoke cigarettes.