As always, the line is:
Your brain doesn't work how you think/wish it did:
- Rationality is nowhere near as strong as you want it to be.
- You are FAR more suggestible than you think
- Rationality is primarily about getting what you want, not finding truth.
- Your memory of an experience and the experience itself differ substantially.
- Resource constraints on attention and willpower matter.
Without invoking Freud, Kahneman's core thesis is: Your brain has two distinct systems (stolen with attribution from Stanovitch):
- slow, deliberate, rational
- fast, intuitive, emotional.
Naturally, 2 dominates unless you're super-extra careful. And then we pretend that 1 was involved somehow.
Two items struck me in the book, one very important...and one highly suspicious.
- There are places where experts are expert, and useful. The discussion of experts and Kahneman's collaboration with a pro-experts expert is wonderful. One useful result: intuitive general appraisals by interviewers are a surprisingly good measure of future results. Our natural, people-awareness is awful good. Roughly as good, indeed, as the predictive success of the best designed system we could find. Hence...someone who is an intuitive expert. So...my wife who's insanely good (>4 σ )in the intuitive expert category gets science supporting her intuition.
- Kahneman's closing chapter says: So now we've examined like 6000 pages of evidence that says people are NOT rational. Therefore the government should fix things. (ed: Especially the non-rational folks in government) To my mind, that's like saying the moon's orbit will eventually decay, therefore we should blow it up. Very fast, very unsupported.
The book is a careful, long, discussion of failure modes in human rationality. It includes prospect theory (Roughly: we don't care about state as much as about delta).
- How to update prospect theory with the falkenstein/hanson status/envy line.
- Why do the researchers believe that people believe the researchers on probabilities. While Kahneman notes some issues near this...I believe that people brains have no intuitive grasp of actual probability...but rather an intuitive grasp of probability categories. There are (roughly) 7 probability gradations (per side): Certain. Almost certain. high probability. about even chances. Low probability. Almost never. Never. I'm relatively convinced that these categories of intuitive probability go a long way towards explaining how people actually act. Why would osmeone be so insane as to pay (as Kahneman demonstrates) $10 per bottle of bug spray to decrease the chance of adverse effects from 15/100,000 to 5/100,000? Why, contrarily will they not accept any similar amount of money to change from 15/100,000 to 16/100,000. Prospect theory handles it a bit, but doesn't seem to completely.