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What Is Cognitive Immunology?

Mental immune systems filter through ideas to spot and remove the bad ones.

Key points

  • Cognitive immunology is the science of mental immunity, a mind's resistance to bad ideas, misinformation and divisive ideologies.
  • Mental immune systems filter ideas and conduct operations to spot and remove bad ideas, but they can quickly deteriorate.
  • Cognitive immunologists devise interventions to boost mental immune performance, which may help protect against damaging, viral ideas.
no attribution required/Pixabay
Our minds have immune systems, just like our bodies do.
Source: no attribution required/Pixabay

Greetings! Permit me to introduce myself. I'm Andy Norman and I study how mental immune systems work. I look at how minds gain and lose the ability to distinguish fact from fiction, and how we can develop our immunity to bad ideas. I thought I'd devote this initial blog post to explaining the basic concepts of cognitive immunology.

Cognitive immunology (CI) is the science of mental immunity. It’s a field of research that goes back to the 1950s and continues in the work of experimentalists like Sander Van Der Linden. The premise is that our minds have immune systems, just as our bodies do. But where bodily immune systems protect us from infectious microbes, mental immune systems protect us from infectious ideas.

Cognitive immunologists study how mental immune systems work. They seek to understand common mental immune disorders and reveal the root causes of mental immune collapse. (A mind’s capacity to distinguish fact from fiction—and good ideas from bad ideas—can deteriorate rapidly.) Cognitive immunologists are shedding light on why epidemics of irrationality occur: They happen when cultural conditions compromise mental immune systems.

Cognitive immunologists also devise (instructional) interventions designed to boost mental immune performance. It’s not enough, it turns out, to teach critical thinking: Citizens of a highly networked society need deep immunity—strong resistance to misinformation, divisive ideologies, and morally disorienting ideas. A systematic approach to building mental immunity offers a more promising path to a sustainable future. In fact, applied cognitive immunology may well be the key to containing damaging outbreaks of unreason. I'll explain why in subsequent posts.

What is mental immunity?

Mental immunity is a mind’s resistance to bad ideas. If a skilled thinker is resistant to a certain kind of propaganda, we can say that she has strong immunity to that propaganda. This means her susceptibility to that propaganda is low. (Immunity and susceptibility are two sides of the same coin.) On the other hand, a small child might be prone to believe in tooth fairies, which means he has limited immunity to ideas about tooth fairies.

What are mental immune systems?

Minds conduct operations to spot and remove bad ideas. (“Bad” here means false, misleading, irresponsible, harmful, or overly problematic.) We ask questions, for example, and sometimes discount the ideas that end up looking shaky. The infrastructure that supports these operations is the mind’s immune system. These systems are distributed in two senses. First, many parts of the brain participate in the assessment of ideas—the frontal and temporal lobes, the hippocampus and the amygdala, for example. Second, the relatively new concept of mental immune function cuts across more traditional categories like critical thinking, curiosity, mindset, and fair-mindedness.

Are mental immune systems real? Not if you mean “A discrete chunk of matter devoted solely to sifting through ideas and removing the bad ones.” On this standard, though, the body’s immune system wouldn’t count as real either. (The body’s immune system is distributed or decentralized.) As long as we define “mental immune system” by its function—its job is to filter ideas—we can be confident that mental immune systems really do exist. Why? Because such filtering really does happen, and something—call it a mental immune system—does the filtering!

Accept this definition of mental immune system, and it follows directly that they're real. Understand that and you gain a conceptual lens that brings our mixed-up, post-truth world into astonishingly clear focus. Do this, and you'll begin to see solutions that have long escaped our notice. More on this in blog posts to come...


Norman, Andy. (2021). Mental Immunity. New York: Harper Wave.

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