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## Thursday, June 27, 2013

### Upon Reflection...

The "Cognitive Reflection Test" recently popped up on Presh Talwalkar's blog:

http://tinyurl.com/ka7w7xk

It's supposed to measure an individual's ability to think through a problem more reflectively or deliberatively, instead of jumping to an initial intuitive judgment.

The simple three questions involved (fairly familiar to many mathematics fans) are:
1) A bat and a ball cost \$1.10 in total. The bat costs \$1.00 more than the ball. How much does the ball cost?

2) If it takes 5 machines 5 minutes to make 5 widgets, how long would it take 100 machines to make 100 widgets?
3) In a lake, there is a patch of lily pads. Every day, the patch doubles in size. If it takes 48 days for the patch to cover the entire lake, how long would it take for the patch to cover half of the lake?
People of a certain impulsive cognitive bent will tend to jump to the wrong answers on most of these questions, while those with a more patient cognitive style will take more time, arriving at correct answers. And these cognitive styles of course have further consequences.

The test has all the outward appearance of pop psychology, and it's hard to imagine a 3-question test as an accurate measure of anything (even if it correlates highly with something), but its creator is a former MIT professor, Shane Frederick (who has, BTW, worked with the esteemed Daniel Kahneman), and he explains the rationale for the test here:

http://mitsloan.mit.edu/newsroom/newsbriefs-0605-frederick.php

His original 2005 paper introducing the test is below:

http://psych.fullerton.edu/MBIRNBAUM/psyCH466/articles/Frederick_CRT_2005.pdf

A lot of follow-up research on the test seems to lend it some credence, although I haven't researched it enough to know how much criticism/skepticism of the test might exist.

...In any event, interesting to see someone attempt to get so much psychological mileage out of just three mathy questions!