As a sort of follow up to this post, here are a couple of additional questions from Shane Frederick’s Cognitive Reflection Test, which highlight the distinction between answers produced by the intuitive motor in our mind and the more effortful one:
1) If it takes 5 machines 5 minutes to make 5 widgets, how long does it take 100 machines to make 100 widgets?
100 minutes or 5 minutes?
2) 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?
24 days or 47 days?
Here, the questions were used in a study on cognitive ease, which captures how people handle information or questions presented in various forms. For questions 1 and 2 above, for example, a collection of students were presented the questions, and asked to solve them. Half of the students had the questions presented on a perfectly legible sheet of paper, while the other half of the students faced questions in a small font with faded print.
As it turns out, of the students who faced clearly written questions, 90% got at least one question wrong. Of the students who faced questions they strained to read, only 35% did! The proposition is that when you are forced to think harder about something as simple as reading the questions, you are already engaging your System 2 (the effortful part) and thinking more critically. As Kahneman phrases: “Cognitive strain, whatever the source, mobilizes System 2, which is more likely to reject the intuitive answer suggested by System 1.”