Imagine you run a small sales force and have a policy of calculating everyone's sales

numbers at the end of each month.

To prevent slackers from staying that way, after each tabulation, you pull the worst

performing employee into a private conference room for a stern conversation.

Now imagine you run the numbers to try to assess whether those stern talks are having

their desired effect.

You discover that your worst performer is almost never the same person twice.

And that, in fact, there's a very reliable month over a month improvement in the performance

of whoever you pull aside.

You'd be pretty excited, right?

Clearly your tough talk is getting results.

This story is actually not so hypothetical.

In fact, when he was a pilot in the Israeli Air Force, economics Nobel laureate Danny

Kahneman heard a similar story from a flight instructor who insisted that when he gave

harsh feedback after novice pilots had a bad flight, he saw big benefits.

Danny relates to this story in his best-selling book Thinking Fast and Slow.

But Danny was pretty sophisticated about statistics and had a feeling that there was an error in

the logic that was leading to this instructor's conclusion about the benefits of delivering

criticism.

In fact, he was quite confident it wasn't the tough talk that was improving the performance

of struggling pilots.

It was something else.

...