**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?**

## Answer:

Did you quickly think the ball costs 10 cents? You’re not alone, but that’s not the right answer.

Let’s see why: If the ball were 10 cents, the bat would be $1.10 (a dollar more than the ball), making the total $1.20, not $1.10. **The right answer is that the ball costs 5 cents**, and the bat, being $1 more, costs $1.05.

The reason many people get the bat-and-ball problem wrong lies in the way our brains are wired to think, a concept neatly framed by psychologists as System 1 and System 2 thinking, popularized by Daniel Kahneman in his book “Thinking, Fast and Slow.” System 1 is our instinctive, automatic response, quick but not always accurate. System 2, in contrast, is our analytical, deliberate thought process, slower but more methodical.

In the bat-and-ball problem, our System 1 quickly jumps to the conclusion that the ball costs 10 cents because it swiftly does the simple math: $1.10 total minus $1 more for the bat equals 10 cents. This intuitive answer feels right and requires minimal mental effort, which is why System 1 prefers it.

However, to arrive at the correct answer, one must engage System 2, recognizing that the initial, instinctive answer was flawed. This requires a conscious, deliberate effort to reassess the problem, something that not everyone does naturally or willingly. Even when given the chance to rethink, many people stick to their initial answer, as found in a study where participants were given versions of the bat-and-ball problem. They provided an initial, quick answer and then had a chance to reconsider. Despite this opportunity for reflection, the majority clung to their first, intuitive answer.

The study further revealed that while most people stayed with their biased initial response, those who did realize their mistake and corrected themselves were able to apply this correct reasoning to similar problems thereafter. This demonstrates the power of recognizing and overcoming our instinctive biases.

This tendency to favor the quick, intuitive answer underscores the importance of not always trusting our initial hunch. It’s crucial to pause, reassess our choices, and consider whether we are genuinely analyzing the problem or simply settling for the most straightforward solution. Cultivating this habit of double-checking our instinctive reactions can lead to more accurate and effective decision-making.