More on critical thinking: what's wrong with our brains

Well, there's not necessarily anything wrong with your gray matter, that's an evaluative judgment. But it evolved to be functional for apes on the African savanna and that's not the world we live in now. Our brains do not simply or reliable convert sensory input into an accurate rendition of reality, and the stories we tell ourselves to make sense out of events -- whether we experience them directly or learn about them from reports of others or mass media -- aren't reliable either. Neither are our memories.

People have written whole books about the myriad ways in which we fool ourselves. In my recent series on clinical trials I have referred, directly or obliquely, to a few of them. But to try to back up to a very broad statement that will fit on a blog post, we can't take in new information without hanging it on a pre-existing framework..Over our  lifetimes, we accumulate a story, a narrative about how the world works -- or possibly more than one that don't necessarily fit together, that we apply to different kinds of problems or under different circumstances. Information that doesn't fit into that story or stories may simply be ignored or rejected; or modified to fit. We notice information that appears to confirm our narrative or is at least compatible with it; and contrary information, one way or another, gets shitcanned.

This is the basis of confirmation bias, and its opposite, which I would call rejection bias. But it also simply creates patches of ignorance that are extremely difficult to fill in. For example, a few years ago I worked with a group of people living with HIV who were advising me on some research, providing the patient's point of view. Some of them had quite a lot of education -- four year college or master's degrees. But they hadn't studied a lot of biology, which is true of the vast majority of people, and that made it almost impossible for me to explain to them what was the most important fact about their health, that is viral drug resistance.

People did understand a basic idea their doctors had told them: that the medications they were taking work to stop the progress of HIV disease, but they can stop working if the people don't take them consistently. All of them, every single one -- and just about every one of a much larger number of people who I surveyed -- interpreted this to mean that their bodies would become resistant to the medication, that drug resistance is a change in the person's body.

For those people who had a history of opioid dependence or other addictive drug use, this was a readily available analogy. For others, it was just a readily understandable idea. It's wrong, but I discovered that explaining why it's wrong and what really happens was a massive project and not attainable in many cases. I talked with people who do health education for people living with HIV and they all basically told me that they don't even bother to try. But the wrong idea can lead to some wrong conclusions and harmful behavior.

You may already know the real story but even if you do, think about how far down to biology 101 you need to go to explain it. You have to explain the nature of a virus, that it's a package of genetic material that has somehow gotten loose in the world. But what does that mean? You have to explain about DNA and RNA and how they work together to manufacture proteins, and what proteins are, which means oh yeah, what cells are. You have to explain how the virus -- or rather, its genetic material -- gets into a cell and what happens when it gets there. You have to explain at least in broad terms how the antiviral medications work, and then you have to explain Darwinian evolution and how this works for a virus in the context of exposure to an antiviral compound. Only then can you explain that drug resistance is a change in the virus, not in your body, and how it comes about. 

This difference is vitally important both for your the sake of your own health -- your "adherence" to your prescriptions, keeping appointments and getting tested -- and to others who you could potentially infect. That's because another part of the story is that if your medications are working fully and you're taking them regularly, you won't be infectious to others. But if you do develop viral drug resistance and don't know it, not only could you infect other people, but you'll infect them with a strain of the virus against which the drugs don't work. 

This story isn't important only to people living with HIV: some slightly different version of it is important for every human being who has a treatable infection of any kind, and for the future of humanity. But apes don't have to understand anything like that. This is just one parable and I could tell you many more. I should also tell you that people's beliefs about taking medications are not only affected by how well they are able to understand the biological story, but also by what is convenient or practical in the context of the rest of their lives. In other words, there's a lot of motivated reasoning going on as well as cognitive burden. But the same basic problems apply to people's political views, and public policy judgements, and how they vote. As Isaac Asimov succinctly put it, "People are stupid." That means all of us. It's hard work not to be.