Chapter Two. How Our Minds Fool Us: The Doors of Perception

Most of us--at least in our less thoughtful moments--are what philosophers call naive realists. We go through our days thinking we see the world more or less as it really is. And that really is naive. The truth is, what we experience is only a thin slice of the world’s full complexity. Yes, we can see a beautiful spectrum of colors, but the rainbow is only a tiny slice of an electromagnetic spectrum that’s mostly invisible to us. Microwaves, radio waves, and x-rays are part of the same spectrum, but we can’t see them. We can’t see the ultraviolet patterns on flowers that guide bees to nectar. We can’t see what’s too far away, or too small, or around corners. Our ears are no better. They pick up just a thin slice of the spectrum of soundwaves. We’re deaf to sounds too high, too low, or too faint to hear. 

These sensory deficits aren’t trivial. If our eyes had been sharp enough to spot deadly viruses and bacteria before microscopes were invented, we might have learned to avoid them, thus saving countless lives. The same is true of dangerous sources of radiation, like radon. But we never knew those things were there. That’s why one of the great triumphs of science is that it’s given us sensory prosthetics like microscopes, telescopes, and radiation sensors that help better understand--and survive in--the world around us.

Our weak senses are just the first filter that information from the outside world has to pass through. The second is attention. What we are conscious of is mostly just what we’re paying attention to, and attention is very selective. Several times a day, for example, a fire truck pulls out of the station down the street from my house, lights flashing and siren blaring. All this is literally designed to make me notice the truck, but I rarely do. Why? Because I’m used to it. My brain has learned it doesn’t need to focus on it, so it focuses on other things.

There’s a good reason we talk about “paying” attention. Attention, like money, is a limited resource. We can only pay attention to a few things at a time, so we have to focus on what’s most immediately important to us, and filter out the rest. That’s why, even though I like listening to audio books when I take road trips, I turn them off when I come to a city. I can’t follow the story and navigate heavy traffic at the same time, and if I tried, I would probably wreck my car.

What’s in our consciousness, then, is not a mirror-image of the world around us, but a pale reconstruction, heavily filtered by our senses, and heavily selected and edited by our brains. That shouldn’t really be surprising, because our brains didn’t evolve to show us a perfect, true reflection of the world (or, for that matter, to be perfectly logical). They evolved to selectively focus on the most important information, so we can navigate and survive in a complex, often dangerous world. Our brains were shaped for (and by) survival, not truth. And it shows in the many ways our thoughts and perceptions differ from reality. We don't think with full information and perfect rationality, but with mental shortcuts that let us make judgments quickly. These shortcuts can work amazingly well, but they can also cause serious distortions in the way we see ourselves, others, and the world around us.

I know people who hear about the distortions, and say, “But it’s so negative to focus on that. Why dwell on it?” My answer is that, while it may be depressing to see how error-prone our minds are, identifying the errors is actually the first step in a very positive direction. If we want to get better at seeing the world clearly, then we have to know the ways our minds distort it, so we can compensate for the distortions. It’s like going to the eye doctor. You have to know the defects in your vision to get glasses that make you see more clearly.