Mar 27 2008
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“ Human cognition has a problem — anecdotal thinking comes naturally whereas scientific thinking does not. The recent medical controversy over whether vaccinations cause autism illustrates this barrier. On the one side are scientists who have been unable to find any causal link between the symptoms of autism and the vaccine’s ingredients. On the other are parents who noticed that shortly after having their children vaccinated autistic symptoms appeared. Anecdotal associations are so powerful that they cause people to ignore contrary evidence. In the vaccination case the imagined culprit for autism’s cause is the preservative thimerosal, yet it breaks down into ethylmercury that is expelled from the body too quickly to have a damaging effect (plus autism continues to be diagnosed in children born after thimerosal was removed from vaccines). The story holds power despite the contrary facts.
The reason for our cognitive disconnect is that the brain evolved to be cautious. We favor anecdotes because false positives (believing there is a connection between A and B when there is not) are usually harmless, whereas false negatives (believing there is no connection between A and B when there is) may take you out of the gene pool. Our brains are `belief engines’ that seek connections.
The reason for our cognitive disconnect is that the brain evolved to be cautious. We favor anecdotes because false positives (believing there is a connection between A and B when there is not) are usually harmless, whereas false negatives (believing there is no connection between A and B when there is) may take you out of the gene pool. Our brains are `belief engines’ that seek connections.
— From Michael Shermer’s review of the new book Charlatan, a book that is going on my wish list, mostly due to the titular charlatan’s particular quackery, which was the inserting of goat testes into the scrotums and near the ovaries of humans.