Here is a simple math problem: “A bat and a ball costs $1.10. The bat costs $1 more than the ball. How much does the ball cost?” (Answer at the end of this article.) Getting the correct answer depends on whether you use System 1 thinking or System 2 thinking, described by Daniel Kahneman, a professor of psychology at Princeton University and author of the recently released bestselling book, “Thinking, Fast and Slow.”
System 1 thinking operates quickly, without effort, or concentrated effort. For example, it is used when driving a car on an empty road, or reading words on a large billboard. System 2 on the other hand involves effort and attention. We use it when doing complicated calculations, consciously adjusting our behavior in a social situation, or when we look for a person wearing a red sweater in a crowd.
Kahneman’s message points to the fact that as human beings we are as irrational as we are rational, as emotional as we are grounded. When faced with uncertain situations people often don’t carefully evaluate the problem or consider the actual details. They invent mental short cuts and in the case of the math problem above, many, skip the math altogether. Being smart doesn’t seem to help either: more than 50% of students at Harvard, Princeton and MIT routinely give the incorrect answer to this simple math problem.
I tested this out on my own college age children. I presented the problem to my daughter, a psychology major and now an MBA student, who never really excelled at math. She thought about it briefly and answered correctly. Then I called my son, an honors student and engineering major at Penn State, and gave him the problem. He considered it for a moment and gave me the wrong answer!
So why does this happen? Why do supposedly smart people struggle with simple math problems? Kahneman points out that we generally rely on System 1 thinking, until things get difficult. The math problem seems easy so many people don’t switch to System 2 and as a result they get the answer wrong. In the case of my daughter, I believe she knew she struggles with math, so mentally she switched right away to System 2 thinking, and did the calculations correctly. My son on the other hand knows he excels at math, relied on System 1, did not use System 2 at all, and got the wrong answer!
Research has shown that depending just on System 1 can lead to serious business issues like investor over confidence and entrepreneurial recklessness. And it’s also easy to develop biases toward every day ideas and issues that appear to be easy or familiar.
For example, a research study done at Harvard Medical School some years ago found that young doctors were consistently and improperly prescribing treatment to patients because instead of concentrating and listening to the entire symptom description by the patient, they were tuning out after a few moments, missing valuable information and then misprescribing treatment.
Overusing System 2 can create problems too! The popular “gorilla video”, created by Daniel Simon, is a good example of what can happen when we focus too much on a task. In the twenty second video the viewer is asked to count the number of times a basketball is passed between members of a team wearing white shirts. About half way through the video a person dressed in a black gorilla suit steps into the activity and briefly looks at the camera and pounds his chest. Typically, about half the viewers miss the gorilla but count the number of passes correctly. The message is clear: concentrated focus is useful but at what cost?
Perhaps you are thinking right now, isn’t it possible to strike a balance between both systems? Yes to some degree, but the fact remains that we are fundamentally unique combinations of rational and irrational thinking. And even if we know these two systems of thinking exist we may not be able to avoid making mistakes because as Kahneman points out in his book System 1 thinking, our irrational and more emotional way of thinking, rules the roost. Just another reason why humility is a more effective approach to life than arrogance!
Oh yeah, and the answer to the math problem: 5 cents.