The Dunning-Kruger Effect, or why you’re not so clever as you think you are

Around 1999 two psychologists called David Dunning and Justin Kruger did some pretty solid empirical studies. They found that people in the early stages of learning things quickly acquired a massive over-confidence. They rapidly overestimated their performance, hopelessly exaggerated their knowledge and proceeded to all all kinds of blunders in both fact and reason. Only by long dedication to a discipline did the provisional nature of their learning become apparent, and the humility to distinguish between conjecture and fact.

All pretty human, you might say. We’ve known about it for centuries. “if you want to know the answer to anything, ask a teenager” as the wise adage goes. You have to be really immature to possess cocksure certainty, and that over a wide range of subjects. So why does the Dunning Kruger effect[1] matter? Firstly because it is the beginning of good empirical evidence for what was previously supposition. And secondly because of journalists.

Journalists? The trouble is that journalists, and the proprietors they obey, are responsible for about 90% of the information we use, particularly in rather important areas like health and public affairs. In a typical day, a working journalist may have to master two or three new things, and then try to explain them to the public. And at the same time accede in all respects to the political and personal belief systems of the editors and newspaper owners who pay their salaries. The potential damage which this can afford was nowhere more clearly shown than in the MMR controversy of the 2000s when large sections of the UK press completely misunderstood and misrepresented scientific and medical findings to the immense detriment of all,

We leave the details to Dr Ben Goldacre who in his masterful Bad Science [1] describes the whole sorry affair, from his point of view in the epicentre. He is surprisingly fair, seeing poor Dr Wakefield more as victim and fall guy as much as anything else. His real ire is reserved for journalists who decided that they knew more about science than the scientists, journalists who believed they (or their owners) were the keepers of the flame of public morality. The Dunning Kruger effect indeed. MMR has passed now. But the same people and papers have gone on to mislead on many weightier matters. They have a right to speak of course; but we have a duty to make sure they speak responsibly from now on. The margin for error has almost disappeared.


[2] Ben Goldacre Bad Science Harper Collins 2008 see especially chapter 15

#mmr #dr andrew wakefield #media ownership #press bias

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