Brain teasers to help teens and adults test cognitive skills…and cognitive biases

brainteaser_considerlindaBrain teaser: Please con­sider Linda, a 31-year-old woman, sin­gle and bright. When she was a stu­dent, in high school and in col­lege too, she was deeply involved in social jus­tice issues, and also par­tic­i­pated in environmental protests. Which is more prob­a­ble about Linda’s occu­pa­tion today?

a) Linda works as a TV reporter;

b) Linda is a bank teller;

c) Linda is a bank teller, and she’s very active in the envi­ron­men­tal movement.

Quick, what’s your answer? a) or b) or c)?

And, in what precise order?

.

Solution

First, ignore how you ranked a), as it is irrelevant to this exercise. The key is this: If you ranked c) as more probable than b), you are wrong…and in very good com­pany. That’s what most people tend to answer the first time they face this particular brain teaser, and it reflects a very pervasive cognitive bias, technically called a “conjunction fallacy.”

Statistically speaking, it is more prob­a­ble that Linda is a bank teller, which is a whole cat­e­gory, that she is both a bank teller AND also active in the envi­ron­men­tal move­ment, which is a sub­set of the whole category of bank tellers.

Right?

More brain teasers to help teens and adults test cognitive skills…and cognitive biases:

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1 Comment »

  1. Reblogged this on Framework 21.

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