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1-Page Summary of The Knowledge Illusion

Overview

The idea of a lone genius is one that many people believe. We are taught in school that great scientific discoveries were made by individuals who were especially smart and talented. According to this narrative, progress is driven by paragons of braininess – those with the most talent and intelligence.

It’s not true that we think alone. In fact, the opposite is more likely to be true. We need a community of people who are aware and can help us when we’re thinking about something. If you don’t have a community of people around you, it would be hard for you to think at all. This passage lays out some reasons why this might be true and proves that we never think alone.

Here are some of the key points from this book. First, we’ll learn why a Venus flytrap isn’t like a jellyfish; how we evolved such big brains; and that pig genes don’t confer pigginess.

Big Idea #1: The illusion of explanatory depth causes us to think we know more than we actually do.

It’s easy to ride a bicycle. Once you learn how to balance, it’s not hard at all. Therefore, it should be simple to explain how a bicycle works.

People tend to overestimate their understanding of how things work, even when they don’t know much. This gap between assumed knowledge and actual knowledge is called the illusion of explanatory depth, or IoED for short. To get an idea of how this works, let’s look at a study by Rebecca Lawson in which she gave her students a drawing that was missing parts from a bike (chain, pedals and sections of the frame). She asked them to complete it with what they thought were the correct answers.

The initial attempts at building bicycles were not very accurate. Some had two sets of pedals, while others lacked crucial parts of the frame. They would have been hard to ride on the open road.

This led students to a realization that they didn’t know as much as they thought.

People have a hard time explaining how everyday objects work. For example, they overestimate their knowledge of bicycles and underestimate their knowledge of zippers, toilets, and wristwatches. Furthermore, people tend to overestimate what they know about everything else as well.

People don’t know as much as they think they do. This is because people are often unaware of what they don’t know or how little they know it. Cognitive scientists have tried to figure out how much we actually know, but their answers are inconclusive.

Big Idea #2: The human brain didn’t evolve to store information and the world is extremely complex.

Throughout the 1960s and 1970s, computer science was in its infancy. Cognitive scientists believed that brains were like computers because of this overlap.

Computing has been compared to the human brain, and one of the foundational models for cognitive science is that our brains function like computers. Thomas Landauer was a pioneer in this field, but he turned this model on its head by calculating how much knowledge humans have in computational terms. He came up with an estimate of around 10 terabytes (a thousand gigabytes) for each person’s memory capacity.

He carried out many other calculations, which all came to the same conclusion: that our brains need about one gigabyte of information. This is a small amount compared to what computers have in them, and it would make sense if we were designed differently than machines. Our brains don’t function as data storage devices because there’s too much information for them to hold.

The world is a complex place. For example, did you know that there isn’t anyone alive who understands all of the intricacies of modern airplanes? Modern planes are too complicated for any one individual to understand completely.