A bat and a ball cost $1.10
The bat costs one dollar more than the ball.
What is the price of the ball?
The price that most likely came to your mind first was $0.10 right?
Well, that is incorrect.
We have two thinking systems that we use to make decisions: the fast, intuitive and unconscious (system one) and the slow, rational, consciously controlled (system two).
What happened was that your impulsive, unconscious system 1 took control and automatically answered by relying on intuition, but unfortunately for you, it answered too fast.
In the majority of situations when we faced with a situation we can’t comprehend, our impulsive unconscious mind calls on our slow, rational mind to assist with helping figure the problem out. However, in the above example system 1 has been tricked! It perceives the problem to be more simple than it actually is, and makes the incorrect assumption it can handle it on its own.
The problem above with the bat and the ball highlight our innate mental laziness. When we use our brain, we tend to opt for the minimum amount of energy required to handle each task. This is known as the law of the least effort and happens because checking the answer with system 2 would require more energy, and our mind thinks it can get away just by using system 1.
This is somewhat unfortunate for us because the utilisation of system 2 is an important aspect of our overall intelligence. Research suggests that practising system 2 orientated tasks, like focus and self-control can result in higher intelligence scores. The puzzle above with the bat and ball illustrates this, as our minds could have checked the answer by using system 2 avoiding the common error altogether.
By being lazy and avoiding utilising our slow, rational, consciously controlled thinking system, our mind is limiting the strength of our intelligence.