I was prompted to write this post by a BBC News story about golf. Researchers found that golfers who talked about a stroke after playing it performed worse on subsequent shots. Novices were largely unaffected but skilled golfers 'were reduced to the level of performance of novices after just five minutes of describing what they did', according to a psychologist at St Andrews University.

We're all familiar with the expert who is unable to pass on his expertise. My father had no problem driving but he found great difficulty explaining to me exactly how to work the pedals in such a way that the vehicle moves off smoothly. And the university professor who can't teach is a cliché. But what we are talking about here is something different. This is about losing a skill by thinking about it.

When I was a child, I learned to play a few simple pieces on the piano. After much repetition, I could play them quite fluently. However, when I stumbled and tried to think how to proceed, I failed. It was very frustrating. The more I thought about it, the more difficult it was to play. This is like the golfers who talked too much. A skill that has been established as a background process is difficult to recall by foreground thinking.

Malcolm Gladwell gives several examples of this phenomenon in his book Blink: The Power of Thinking without Thinking. It seems an expert is likely to make a better judgement by being forced into a snap decision than if asked to think about it and discuss it. What does this say about the opinions of expert panels, who debate at length before making their pronouncement? What does it say about the management of a skilled engineer, who is asked to justify what she is doing at every stage?

Novice are novices and had better think carefully. But experts should perhaps get on with doing what they are good at and not think about it too much!

BBC News: Overthinking 'disrupts golf putt'