Strain and Effort
Kahneman describes cognitive strain as both an experience of effortful System 2 thinking and a possible prompt for closer analysis. He illustrates the claim with intuitive-answer puzzles and a study comparing readable and difficult-to-read fonts.
THE IDEA
STRAIN AND EFFORT
The symmetry of many associative connections was a dominant theme in the discussion of associative coherence. People who are made to “smile” or “frown” by sticking a pencil in their mouth or holding a ball between their furrowed brows are prone to experience the emotions that frowning and smiling normally express. The same self-reinforcing reciprocity is found in studies of cognitive ease. On the one hand, cognitive strain is experienced when the effortful operations of System 2 are engaged. On the other hand, the experience of cognitive strain, whatever its source, tends to mobilize System 2, shifting people’s approach to problems from a casual intuitive mode to a more engaged and analytic mode.
The bat-and-ball problem tests people’s tendency to give the first answer that comes to mind without checking it. Shane Frederick’s Cognitive Reflection Test consists of the bat-and-ball problem and two others, all chosen because they evoke an immediate intuitive answer that is incorrect. The other two items in the CRT are:
If it takes 5 machines 5 minutes to make 5 widgets, how long would it take 100 machines to make 100 widgets?
100 minutes OR 5 minutes
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
The answers appear in the corresponding examples below; the source also points to a footnote.* The experimenters recruited 40 Princeton students to take the CRT. Half of them saw the puzzles in a small font in washed-out gray print. The puzzles were legible, but the font induced cognitive strain. The results tell a clear story: 90% of the students who saw the CRT in normal font made at least one mistake in the test, but the proportion dropped to 35% when the font was barely legible. You read this correctly: performance was better with the bad font. Cognitive strain, whatever its source, mobilizes System 2, which is more likely to reject the intuitive answer suggested by System 1.
When to use it
When comparing study formats, check actual understanding and retention rather than assuming that unfamiliar typography improves learning.
Decision-making under uncertainty: deliberately slowing down and questioning initial intuitions.
In an interface for a consequential action, give users a clear opportunity to pause and review the decision while keeping the information readable.
When teaching critical thinking, ask students to explain and check their first answers to problems designed to evoke intuitive errors.
FROM THEORY TO EVERYDAY LIFE
In practice
Bat-and-Ball Problem
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? The intuitive answer is 10 cents, but the correct answer is 5 cents.
Machines and Widgets Problem
If it takes 5 machines 5 minutes to make 5 widgets, how long would it take 100 machines to make 100 widgets? Intuitive answer: 100 minutes; correct answer: 5 minutes.
Lily Pad Doubling Problem
In a lake, a patch of lily pads doubles every day. If it takes 48 days to cover the lake, how long to cover half? Intuitive answer: 24 days; correct answer: 47 days.
Font Experiment
40 Princeton students took the CRT. Half saw it in a small, washed-out gray font (inducing cognitive strain). 90% of those with normal font made at least one mistake, but only 35% of those with the strained font made mistakes.
A MOMENT TO REFLECT
Put it to work.
When have you experienced cognitive strain that helped you think more carefully about a decision?
What evidence would you need before concluding that a difficult-to-read font improves analysis rather than merely making a task harder?
What everyday situations might benefit from a shift from System 1 to System 2 thinking through cognitive strain?
Often confused with
CONTINUE THE CONVERSATION
Source texts
- Thinking, Fast and Slow (Daniel Kahneman)