A bat and ball costs $1.10 in total.
The bat costs one dollar more than the ball.
How much does the ball cost?
If you instantly produced the answer of: 10 cents, you’d be quite normal (more than 50% of Harvard, MIT and Princeton students respond this way) but completely wrong.
The ‘bat and ball’ problem is one of the ways Nobel Prize winning psychologist Daniel Kahneman illustrates how our ‘System 1’ – our rapid, subconscious , intuitive processing mode – can lead to biased or incomplete perception and decision making. Often, System 1 is very helpful in guiding our thinking, but sometimes it leads us astray.
So, have you worked out the correct answer yet? It is, of course: 5 cents. The bat, therefore costs 5 cents plus one dollar ($1.05) which added to the $0.05 cost of the ball gives us the total cost of $1.10.
But that answer, even for highly educated, successful people, doesn’t come easily. And that’s because it requires us to switch on ‘System 2’ – our slow, deliberate, analytical mode. In this mode, we stop thinking automatically and instead use rational, conscious intelligence to really ‘think through’ a problem.
In our classrooms, it is critical that we give space and time to develop our students’ System 2 thinking. Whilst skills such as authentic responding, rapid prototyping, and creative intuition can fuel an exciting classroom dynamic, it is the development of slow, System 2 thinking that allows students to cope with complex problems. In the accelerated, information-heavy world in which our students are growing up, it is only via practice that they can become adept at recognising times when they need to slow down – to really think.