The Knowledge Illusion, by Steven Sloman and Philip Fernbach.


Try this out on a friend. Ask them these questions:

  1. On a scale of 1 to 7, rate how well you understand how a zip works.
  2. How does a zip work? Describe in as much detail as you can all  the steps in a zip’s operation.
  3. 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.

Brain training exercises just make you better at brain training exercises, by Christian Jarrett.

Buy into a brain training exercise programme, and you will be given time-consuming and difficult exercises to do. The harder you work, the more you will progress. You might even bring down your “brain age.” But you won’t actually be making yourself any cleverer. All you will be doing is wasting time, and making the authors of the brain training exercise programme richer.

You’d be much better off learning a new language, doing some physical exercise, or just sleeping for longer.

Brain training exercises just make you better at brain training exercises.

“A person who spends many hours on brain training games but never engages in any real-world challenges is like the karate pupil who has only ever performed solo exercises in the dojo. Woe betide they ever find themselves in a fight.”

N.B. The BPS research digest is brilliant, and just at the right level for A level students. Read it.

Thinking, Fast and Slow, by Daniel Kahneman.


This American psychologist recently won the Nobel Prize for his work on cognition. This book, published in 2011, is about how, when making intuitive decisions, we make mistakes that are highly predictable. It is an enjoyable read and it makes you think about how you think. I am personally convinced that in a few year’s time Kahneman’s name will be as widely known as Freud or Zimbardo or Milgram. Read it now and amaze your friends and teachers with your up-to-date knowledge.