The following post is the first in a series exploring 'mind and culture: pathways to economic development,' the theme of the World Bank's upcoming World Development Report 2015.
Try to guess the answer to the question:
How many seven -letter words of which the sixth letter is “N” (_ _ _ _ _ N _) would you expect to find in four pages of a novel in English (about 2,000 words)?
Now guess the answer to another question:
How many seven-letter words of which the last three letters are “ING” (_ _ _ _ ING) would you expect to find in the same four pages?
If you are responding as most people have, then your estimate is several times greater for ING words than for _N_ words. This violates logic. With some reflection, it’s easy to see that every ____ING word is also an _____N_ word. The mistake is famous and so is its explanation. _ING words are a standard category, _N_ words are not, and standard categories shape how we think. We confuse what it is easy to think of with what is frequent. This bias, called the availability bias, is just one of a multitude of biases that appear to be universal.1