The Curse of Knowledge

2 min readAug 2, 2018

Why you should never blindly trust an expert.

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In 1997, a Scottish police officer named Shirley McKie found herself in a terrifying set of circumstances.

Her fingerprint had been found at the murder scene of a woman called Marion Ross in the burgh of Kilmarnock, East Ayrshire.

Shirley was completely dumbstruck. After all, she had never set foot in the house in her life.

However, despite her protestations, she was eventually suspended and then charged with perjury.


Simply because four finger print experts from the Scottish Criminal Record Office were unequivocal in claiming it was hers.

Some years later, a subsequent enquiry revealed that officer McKie had, in fact, been telling the truth along. It found systematic errors in the fingerprinting services’ approach and eventually awarded her £750,000 in compensation.

Chairman Sir Anthony Campbell said at the time that fingerprint examiners were “presently ill-equipped to reason their conclusions as they are accustomed to regarding their conclusions as a matter of certainty and seldom challenged”.

This extraordinary story highlights the very real danger of putting blind trust in experts.

Whilst they are in general safe to rely on, experts suffer from something known as the ‘Curse of Knowledge.’ This is a cognitive bias that leads people highly informed about a topic to be unable to think about it with a fresh pair of eyes.

The billionaire inventor James Dyson fell victim to this mentality early on in his quest to create his revolutionary Dyson DC-01.

When he first proposed his suction-less vacuum cleaner modelled on cyclone technology his then board quickly dismissed it saying that “If it was truly worthwhile doing then Hoover or Electrolux would have already made it.”

They failed to think beyond the accepted ‘expert’ opinion of what a vacuum cleaner should be like. This type of ‘narrow’ thinking is just one of the potential downsides associated with experts.

Others include:

  1. Experts look for ways to apply their skills beyond where it’s actually useful. E.g. a doctor promoting treatment where prevention would be better.
  2. Once an expert decides on something, it can be very difficult to challenge their decision. Even if it’s the wrong one.
  3. As a consequence, their advice is readily accepted and rarely questioned.

It seems, therefore, that knowledge can be both a blessing and a curse. As the psychologist Abraham Maslow wisely opined, “To a man with a hammer everything looks like a nail.”




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