When “normal” feels like winning (or losing) – Danny Kahneman on regression to the mean

Danny [Kahneman] was then helping the Israeli Air Force to train fighter pilots. He’d noticed that the instructors believed that, in teaching men to fly jets, criticism was more powerful than praise. They’d explained to Danny that he only needed to see what happened after they praised a pilot for having performed especially well, or criticized him for performing especially badly. The pilot who was praised always performed worse the next time out, and the pilot who was criticized always performed better.

Danny watched for a bit and then explained to them what was actually going on: The pilot who was praised because he had flown exceptionally well, like the pilot who was chastised after he had flown exceptionally badly, simply were regressing to the mean. They’d have tended to perform better (or worse) even if the teacher had said nothing at all. An illusion of the mind tricked teachers – and probably many others – into thinking that their words were less effective when they gave pleasure than when they gave pain.

“Because we tend to reward others when they do well and punish them when they do badly, and because there is regression to the mean,” Danny later wrote, “it is part of the human condition that we are statistically punished for rewarding others and rewarded for punishing them.”

Danny Kahneman, in Michael LewisThe Undoing Project

A couple of weeks ago, DriverlessCoc had an unexpected hit: 161 views in a day*, thanks largely to a generous retweet about this post from Tom Peters. It was a fun day.

The following day DC got about ten views – the high side of “normal” – but of course it felt like a disappointing performance.

This is a danger that comes with doing well – your next performance will probably be worse as you regress to your mean (or “normal” performance).

The flipside is also true: you might pat yourself on the back after a recovery to “normal” after a bad performance, when in reality your performance is utterly unexceptional.

So what?

So… beware of your feelings about short-term peaks and troughs in your own or your team’s performance, and concentrate on shifting that mean.

So… (and is just occurred to me) think again about what’s happening when shouting at your kids seems to fix their behaviour, or praising them seems to lead to them falling off the wagon… Are they responding to your messages, or just reverting to the mean? (I think it’s a bit of both).

A more consistent, better average is almost always better than a few excellent – but exceptional – peaks.

*161 views is the DC equivalent of winning the internet

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