Overstory is an amazingly detailed, beautifully written book. Though it is fiction, it is filled with many characters that are closely based on real people. Reading it felt like like a form of forest bathing, an immersion in details of different species of trees, forest ecosystems, and the human relationships with them.
Among the many insights shared in this book there is reference to a famous test which illustrates confirmation bias, a common human subconscious behavior.
The Famous Four Card Task
This is the test. Suppose each card has a number on one side and a letter on the other. Which of these cards are worth turning over if you want to know whether the statement below is false?
“If a card has a vowel on one side, then it has an even number on the other side.”
To take the test visit The Famous Four Card Task.
What did you think?
It is also worth noting that Overstory credits this test to the book, “The Ape Inside Us”. This too is a fictional book but it is based on the real book The Ape Within Us. The test is real, but actually from another book, Psychology of Reasoning: Structure and Content.