McArthur Wheeler’s infamous career as a bank robber was short-lived. He robbed two Pittsburgh banks on single day in 1995 – but didn’t keep the money for long. Rather than using a mask, as tradition dictates, he had the misguided idea of rubbing lemon juice on his face. He mistakenly believed that since it was used in invisible ink it would prevent security cameras from recording him. The police caught Wheeler on the day of the robbery and he was soon sentenced to 24 years in prison.

The story of the failed robbery is of interest to marketers as it inspired two Cornell psychologists, David Dunning and Justin Kruger, to come up with an important insight into human behaviour.

Illusory self-belief

The psychologists wondered how such an inept criminal could think that he had the necessary skill to successfully evade capture? More importantly they decided to test whether this lack of self-knowledge was widespread. They recruited students to take a series of maths and grammar tests and then asked them to predict how well they would do compared to their peers.

The results? Just like Wheeler participants were poor judges of performance, under-performers systematically over-estimated their ability. Across four studies participants in the bottom quartile tended to think they were significantly above average in terms of performance. The findings, of what is now known as the Dunning-Kruger effect, have been replicated repeatedly. Interestingly, it even occurs amongst academics who should be aware of the bias. A classic study by K. Patricia Cross found that more than 90% of lecturers at the University of Nebraska thought they were better than average at teaching.

The marketing application

The Dunning-Kruger effect is of interest to marketers as it provides a powerful tool to change behaviour. Since most people think of themselves as above average a brand that communicates typical behaviour should encourage people to perform higher.

Take charitable donations as an example. A survey, undertaken by ZenithOptimedia amongst 521 nationally representative people, found that 64% thought they were more generous than their peers. If charities communicated the average donation level to potential donors it would encourage them to exceed that amount. Unless donors gave a higher amount how could they continue to think of themselves as more generous than their peers?

There are commercial applications too. Sportswear brands, for example, could boost the amount spent by customers on shoes by telling them the average purchase price. Surely an above average athlete would want to spend more than the other joggers on the site? Similarly a bookworm could be encouraged to read more, a gambler to stake more and a savvy saver to put more aside if compared to the norm.

The potential list of uses is broad, it just needs enlightened marketers to apply it. Since most marketers reading this article will be above average it surely won’t be long before the Dunning-Kruger effect is being applied fruitfully.

Editor: For more on how the Dunning-Kruger Effect manifests among advertising practitioners – read Eaon Pritchard's post.