The widespread popularity of conspiracy theory thinking is a testament to the degree to which many people misunderstand how the world works.

The mind is prone to many misconceptions. In recent decades, scientists have conducted experiments that map some of them. One is known as the “Linda problem.”

In the early 1980s, psychologists Amos Tversky and Daniel Kahneman (who won the Nobel Prize in economics in 2002) posed the following question:

Linda is 31 years old, single, outspoken and very bright. She majored in philosophy. As a student, she was deeply concerned with issues of discrimination and social justice and also participated in anti-nuclear demonstrations.

They asked whether it was more likely that Linda was:
1) a bank teller, or
2) a bank teller and an active feminist.

85 per cent answered that Linda was more likely to be a bank teller and a feminist than just a bank teller. But this is statistically impossible. If Linda is a bank teller and a feminist, than she must obviously be a bank teller. But one can envision circumstances in which she could be a bank teller but not a feminist. So, the probability of her being a member of a larger group and a smaller subset must be less than that of simply being a member of the larger group.

Most people did not see the problem this way, however. Because Linda’s biography makes her seem more like a feminist than a bank teller, they preferred the choice that included “feminist.”

The “Linda problem” illustrates one way in which our mind plays tricks on us, in this case by thinking in terms of stereotypes, not probabilities.

Many anti-American conspiracy theories rest on another type of unfounded stereotype: that of the U.S. government as devilishly clever, superhumanly effective, extraordinarily daring and unbelievably wicked. In my experience, bureaucrats are much more likely to be overly prudent, sometimes cautious to a fault.