I work in a numbers industry, where the meaning of average is known in its precise numerical term. Yet all my staff who HAVE to beat an average (that's their job), believe they are better than average. And all the the people at our competitors doing the same job also believe they are better than average.

Now clearly half of them are wrong, and they all know that collectively the entire industry cannot be better than average. Yet these are the same people that determine the fate of companies, economies and industries. They control literally trillions of dollars collectively, my own teams run billions.

If you do the maths, on average every single one of them is overconfident. In other words they over-emphasise their own predictive ability and accuracy.

"A trait of human conversations is that the meaning of words can shift mid-conversation and no-one notices." Dawnstorm a common behavioral trait is what you're claiming here. You might be right, I've not seen the testing on this (though I have on all of the above). Now if you're right and let's assume you are then do you think everybody knows this? If not then you have a considerable comparative advantage which at judicious moments you can apply to further your own agenda. Furthering your own agenda precisely because there ARE common human behavioral traits.

Scott, I haven't read that book, I'll look it up.