The Knowledge Illusion Why We Never Think Alone

Steven Sloman and Philip Fernbach

It may be disappointing to understand that we know less as individuals than we realize, but continuing to be deceived by this illusion can  lead to poor decisions and unfortunate actions. “Most things are complicated, even things that seem simple.” “Complexity abounds. If everybody understood this, our society would be much less polarized. Instead of appreciating complexity, people tend to affiliate with one or another social dogma.”


Many of us are frustrated by how much we forget – or remember incorrectly – but “remembering everything is in conflict with what the mind does best: abstraction.” Remembering everything “would make us less successful at what we evolved to do. The mind is busy trying to choose actions by picking out the most useful stuff and leaving the rest behind.”reminder


In conjunction with their theme of pooled intelligence, Sloman and Fernbach explain how our thinking is embodied – not just with our own bodies but also with the people and things around us. “The fact that thought is more effective when it is done in conjunction with the physical world suggests that thought is not a disembodied process that takes place on a stage inside the head. Mental activities do not simply occur in the brain. Rather, the brain is only one part of a processing system that also includes the body (including the eyes) and other aspects of the world.” “Our bodies produce feelings to make us aware and warn us.” “In other words, the mind is not in the brain. Rather, the brain is in the mind. The mind uses the brain and other things to process information.” This is not easy to grasp when we already “know” that all thinking takes place in the brain because that is what has been understood for hundreds of years. For additional information and perspective, you may want to reference the following.

A challenging question to answer is: Why have humans evolved such large brains? Large brains are very expensive. They use a lot of energy, they make childbirth dangerous for the mother and the child, and they require a prolonged period of development. What advantage is so important to outweigh these problems? The explanation may be “that large brains are specifically suited to support the skills necessary to live in a community.” “People are built to collaborate.” “The transmission of knowledge enabled by our social brains via language, cooperation, and the division of labor accumulates to create a culture. It is one of the most important ingredients in the human success story. Human capabilities are constantly increasing, but not because individuals are getting smarter. Unlike beehives, which have operated pretty much the same way for millions of years, our shared pursuits are always growing more complex and our shared intelligence more powerful.” “The smartest among us – in the sense of being most successful – may well be those who are best able to understand others.”


The authors spend the second half of the book “exploring how many of society’s most pressing problems stem from the knowledge illusion” and how change, particularly that triggered by technology, tends to cause us to “lose touch with what really matters.” It is easier and more comfortable to discuss issues with people with whom we agree, but “one common finding is that when people with like minds discuss an issue together, they become more polarized.” This is not informed decision-making. To probe decision-making, Sloman, Fernbach, and other researches have asked people about issues about which they have strong opinions and then probe how much they understand. Striking examples relate to the Affordable Care Act, support for military intervention in the Ukraine, and about the labeling of GMO foods. The results clearly indicate that “public opinion is more extreme than people’s understanding justifies.”non-gmo-logo-400x400

“Recognizing the limits of our understanding should make us more humble, opening our minds to other people’s ideas and ways of thinking.” “Intuition gives us a simplified, course, and usually good enough analysis, and this gives us the illusion that we know a fair amount. But when we deliberate, we come to appreciate how complex things actually are and this reveals to us how little we actually know.” “A mature electorate is one that makes the effort to appreciate a leader who recognizes that the world is complex and hard to understand.” This approach applies to all important decisions, not just voting.  The authors hope that, by helping us understand the routine pitfalls of our thinking, we can improve our decision-making.