Intuition is fast and mostly good enough

Daniel Kahneman is famous for his work on the psychology of judgment and decision-making. He was awarded the Nobel Prize in Economic Sciences in 2002. His work challenged the assumption (widely held by economists) that humans are rational. Together with his friend and colleague Amos Tversky, Kahneman established a cognitive basis for the biases that characterize human reasoning.

In his book Thinking Fast and Slow, Kahneman details how humans make judgments about the world. Human thinking follows two modes: 1. fast—intuitively and emotionally, and 2. slow—deliberately and more logically. The first, commonly called system 1, is easy, fast, and efficient. System 2 is harder work. When we make intuitive judgments via system 1, we are prone to particular errors in predictable ways. For example, loss aversion is a bias toward avoiding losses over acquiring equivalent gains. Individuals prefer not to lose fifty dollars over finding fifty dollars. These are called cognitive biases and there are many. We can’t avoid these biases. Even Kahneman says he is subject to all of them! But we can be more aware of these biases and when they may be operating.

The trick with cognitive biases is not to try to memorize or unlearn them but rather to minimize their impact on your judgment. Kahneman advises delaying forming an intuition. This can be hard to do.

Try this test:

  1. A coffee and a candy cost $1.10 in total. The coffee costs a dollar more than the candy. How much does the candy cost?
  2. If it takes 5 machines 5 minutes to make 5 lattes, how long would it take 100 machines to make 100 lattes?
  3. In a cafe, there is a wet patch on the floor from a leaking espresso machine. Every day, the patch doubles in size because no one mops it up. If it takes 48 days for the patch to cover the entire floor of the store, how long would it take for the patch to cover half the floor?

  1. Intuitive answer = 10 cents. Correct answer = 5 cents
  2. Intuitive answer = 100 minutes. Correct answer = 5 minutes
  3. Intuitive answer = 24 days. Correct answer = 47 days

How did you do? Were you able to resist blurting out the intuitive (but incorrect) answer that naturally comes to mind and instead engage mathematical reasoning skills to come up with the correct answer?

This quiz is called the Cognitive Reflection Test and it is designed to measure a person's tendency to override an incorrect "gut" response and engage in further reflection to find a correct answer. Psychologist Shane Frederick first described this quiz in 2005. It correlates highly with many measures of cognitive biases.

You might have answered correctly but we’d bet that you experienced having the intuitive answer arise anyway. Even if you’d done this test before, the intuitive answer would still appear. The beauty of this test is its power to demonstrate just how hard it is to suppress an intuition, even if we know instinctively that it’s wrong.

Intuition is tacit knowledge built from experience. Do you sometimes just know something? Or do you know how to do something yet are unable to explain it? Chick sexers would understand.

The neuroscientist David Eagleman, in his book Incognito, tells a story to illustrate how everything about our interaction with the world rests on a process of unconscious learning. The popular home of chick sexing is Japan, where, in the 1930s, poultry farmers would travel to the Zen-Nippon Chick Sexing School to learn the technique. Chicken sexing is an incredibly difficult task because the male and female chicks look almost identical. Training new sexers at the school involved the master standing over the apprentice and watching. The students would pick up a chick, turn it over, inspect it and then throw it one bin or the other. The master would give them “yes” or “no” feedback. At the end of training, the student’s brain was fully trained to masterful levels. Intuition developed unconsciously.

Intuition is the ability to acquire knowledge unconsciously. The process is non-sequential and takes into account both rational and emotional elements. The result is direct knowledge without rational inference. Intuition is often cyclical and makes use of deeper knowledge collected over time. All decision-making processes make use of intuition. Using intuition is fast and often automatic.

Reliable intuition utilizes many years of practice and experience. It comes from a learning process that translates huge amounts of facts, patterns, and concepts into both tacit and explicit knowledge. We experience intuition as knowing without consciousness, recognizing a pattern, remembering without specific facts, or simply having a gut feel or instinct about something. Intuition is not “irrationality” or the opposite of logical reasoning.

Intuitions are personal; they reside inside our own heads. They are a product of our evolution. They are fast and efficient and usually good enough for us to make our way successfully through the world. People like to use their intuition. It’s perhaps the ultimate expression of trust in ourselves. But our intuitions are based on our experience, and how we update our knowledge is based on a complex set of tradeoffs, tensions, and limitations.

Our intuitions evolved in the physical world of our senses. We are best at applying our intuitions in situations where our tacit knowledge is relevant and salient. But our intuitions fail because the world is more complex than we can intuitively grasp.

Great Human Strength: Intuition is fast, is satisfying, and usually pretty good.

Great Human Weakness: Intuition is hard to suppress. Intuition is fallible, especially when outside our realm of experience or when not grounded in the physical world of our senses.

Machine Opportunity: Designs that complement our System 1 and 2 reasoning by helping us engage System 2 when required and making System 1 better.

Machine Threat: Designs that cause us to overuse intuition.