In Adaptive Thinking, Gerd Gigerenzer follows up on his earlier book, The Empire of Chance. Part of his new book, Adaptive Thinking, is a continuation of his earlier discussion. Gigerenzer reacts against the dominance of significance testing, and looks closely at how it has shaped psychological theories. In particular, Gigerenzer places the "cognitive illusions" of Tversky, Khanneman, and many other behavioral scientists under very close scrutiny.
Gigerenzer's main thrust is that humans did not evolve in the psychology laboratory, with good command of probability theory to help them work on word problems. Instead, he argues, humans evolved in environments with lots of noise, and had to use regular features of the world to develop simple and effective rules of action. In this, he echoes and extends the work by economist Herbert Simon in the 1950s.
Take one of his examples: You live in Detroit. 1 in 100 new cars of brand X break down. 10 in 100 cars of brand Y break down. Your friend has car X, and it just broke down yesterday. Which should you buy? Well, clearly if you're "rational" you buy brand X. But consider:
You live in a jungle. 1 in 100 children is eaten by a crocodile while swimming in the river. 10 in 100 falls to their death while playing in the tree. Just yesterday, little Bobby was swimming and got eaten by a crocodile. Where should you let your kid play?
According to Tversky, Khanneman, and other modern cognitive scientists, you would be "irrational" to fear the river, since the long term probability of dying there is still only 2 out of 100.
If we evolved in the jungle situation, is it any wonder that most people rely on the advice of their friend in the car situation? Does this make them "irrational?"
Gigerenzer looks at the history of decision research, and offers a concrete and predictive program for the study of human rationality. The book is fairly short, very interesting, and casts serious doubt on many aspects of contemporary cognitive research. I recommend it to anyone with an interest in psychology or decision making, even non professionals.
