Anti-vaccine advocacy reflects a spectacular failure of critical thinking


One of the greatest ironies of the anti-vaccine movement is that its proponents imagine themselves to be deep, incisive thinkers when they are the exact opposite. Their beliefs reflect immature cognitive errors and a spectacular failure of critical thinking.

There are a lot of different definitions of critical thinking, including:

[Critical thinking is] thinking about one’s thinking in a manner designed to organize and clarify, raise the efficiency of, and recognize errors and biases in one’s own thinking.

Anti-vaxxers never ask themselves what they DON’T know.

Critical thinking is often contrasted with traditional education techniques like lectures and memorization. Whereas lectures and memorization result in students who remember the important dates of the Revolutionary War, for example, critical thinking leads to students who understand why the war happened.

In my view there are four pillars to critical thinking and those pillars can be expressed as self-directed questions.

1. What do I know?

2. How do I know it?

3. What don’t I know?

4. How can I learn it?

What do I know?

Both critical thinkers and uncritical thinkers like anti-vaxxers are clear on what they know. The differences are encompassed by answers to the other three questions.

How do I know what I know?

For uncritical thinkers like anti-vaxxers, the answer is simple and concise. They “know” that vaccines are harmful because someone else told them so. They like to dress it up in their own minds by insisting that they “did their research,” but what they really mean is that they ignored experts and chose to believe random people on the internet.

Anti-vaxxers have never seen the inside of a laboratory or a medical library, the places where real medical research occurs. Most have never read a single scientific paper beyond the abstract and wouldn’t understand one if they did. They lack basic knowledge of immunology, statistics and the scientific method. They have the cognitive maturity of a four year old who imagines that addition and subtraction reflect the sum total of knowledge in mathematics. They are so limited in their understanding of science that they don’t even understand their limitations.

Anti-vaxxers imagine themselves as bold thinkers because they reject the assertions of experts without realizing that reflexively rejecting experts is the same as reflexively embracing them. Neither involves thinking; both are responses to authority.

In contrast, critical thinkers know what they know by reading authoritative texts and scientific literature. In addition to reading expert literature that confirms their beliefs, they are fully conversant with the scientific literature that questions their beliefs or contradicts them.

The breadth of knowledge of vaccine experts exceeds that of anti-vaxxers by orders of magnitude.

What don’t I know?

This is where the rubber hits the road in critical thinking. Critical thinkers always ask themselves what they don’t know, recognizing that gaps in knowledge can lead to faulty reasoning.

Anti-vaxxers never ask themselves what they don’t know. Their cognitive immaturity (and their vanity) leads them to imagine that they know everything worth knowing.

That cognitive immaturity is reflected in their style of argument, best captured by the phrase: “but what about?”. They parachute on to skeptic blogs and Facebook pages and offer what they believe to be devastating rejoinders: “But what about this out of date paper?” “But what about the blathering of this anti-vaxxer who once taught an extension course at Harvard?” “But what about the fact that cases of this disease dropped between epidemics before the existence of vaccines?”

They lack the critical thinking skills to answer their own questions. Since they have no understanding of the scientific method, they can’t appreciate that a single, out of date paper is meaningless; only the breadth of the entire literature matters. Since they are incapable of reading that literature, they have no idea what their preferred paper actually shows; they only know what some other anti-vaxxers told them it shows. They don’t even know if the paper was contradicted by subsequent research or even retracted due to violating principles of scientific reporting. Since they have no understanding of statistics they are ignorant of the fact that disease incidence can fall from one year to the next without it being evidence that the disease is disappearing. And although they claim to reject arguments from authority they are quick to embrace arguments from anti-vax celebrities.

How can I learn what I don’t know?

Anti-vaxxers don’t know what they don’t know so they are unlikely to ask themselves this question spontaneously. However, as soon as they engage with people who know a great deal more (which is nearly everyone who has professional education and training), they become aware that there’s lots they don’t know.

Critical thinkers will attempt to remedy their deficits. They will do background research in science and statistics; they will review the entire literature; they will seek out help reading and interpreting scientific papers. Anti-vaxxers, who are cognitively immature, will respond immaturely — accusing anyone who knows more of being a shill for the pharmaceutical industry. It’s the intellectual equivalent of calling your opponent a poopy-head.

Anti-vaccine advocacy reflects a spectacular failure of critical thinking because it is missing one of the pillars: interrogating oneself to determine what you don’t know, not merely what you do know. Anti-vaxxers flatter themselves by imagining that they are engaged in deep thinking when they haven’t been thinking at all, just dumbly imbibing, believing and repeating nonsense from other equally ignorant fools.