Try this out on a friend. Ask them these questions:
- On a scale of 1 to 7, rate how well you understand how a zip works.
- How does a zip work? Describe in as much detail as you can all the steps in a zip’s operation.
- Now, on the same 1 to 7 scale, rate your knowledge of how a zip works again.
They will almost certainly give a lower estimate the second time, becuase the task has revealed to them how little they actually understand about a zip. This is called the Illusion of Explanatory Depth. The truly terrifying thing is that we are all subject to this illusion, about all of our knowledge. None of us actually know a fraction of the stuff that we think we know.
The reason for this is that we confuse other people’s knowledge with our own. Because other people that we trust understand stuff, we think that we understand that stuff ourselves. We are all prey to this confusion, from A-level students (and teachers), to scientists, politicians, and “experts” of all kinds.
Sloman and Fernback argue that this is because our minds are equipped and optimised for thinking in groups, rather than individually.
The ideas in this book are related to the ideas of Tversky and Kahneman, which are outlined in Thinking Fast and Slow. Thinking Fast and Slow is a longer and more scientifically dense book, but The Knowledge Illusion is also a really fun read, and much shorter.
James Garvey decided to write this book after attending a lecture by a high-flying Oxford theologian. In the Q & A, he raised his hand and posed a killer objection to one of the points that the speaker had made. His neighbour leaned over to him and whispered “you’ve got him!”
Garvey had won plainly won the argument. Unfortunately, it made no difference whatsoever. The speaker didn’t change his mind. He seemed to consider the question, and then just carried on, ignoring the point that had been made.
The point is that people are not really swayed by rational arguments – even ones that are obviously true. Rather people make up their minds on the basis of emotional factors, and then use rational argument to justify their already fixed ideas.
This sad psychological fact has long been know to advertisers and politicians, who use industrial strength emotional and cognitive manipulation to implant in our minds the opinions they wish us to have. No-one is immune from this manipulation. The only real defence is knowledge, so at least we can be aware of how we are being controlled and directed for the benefit of others.
In The Persuaders, James Garvey takes us on a tour of what he has discovered about the persuasion industry. He’s a philosopher, but there’s plenty of scientific psychology in the book. Required reading for any psychologist interested in democracy and free will.