Thinking Clearly · Lesson 2 of 6
Why we don’t think clearly
Our minds are wired for speed, not accuracy. Meet System 1 and System 2, catch them at work in two quick puzzles, and see five biases that shape decisions without our noticing.
Three reasons
Clear thinking is hard for three reasons, and none of them is a lack of intelligence:
- Human wiring. We have two ways of thinking, and the fast one does most of the work.
- Human bias. The fast way takes shortcuts, and the shortcuts have predictable errors.
- Complex systems. In many situations cause and effect are far apart in time and place, so our intuitions about them are simply wrong. That is the next lesson.
System 1 and System 2
Look at a photograph of an angry face. You don’t decide that the person is angry; you just know, instantly, without effort. You probably also know that they are about to shout.
Now work out 17 × 37 in your head.
That felt completely different: slow, deliberate, effortful. You had to hold numbers in memory and follow steps. (It’s 629.)
The psychologist Daniel Kahneman calls these System 1 and System 2:
| System 1 | System 2 |
|---|---|
| Fast | Slow |
| Unconscious, automatic | Conscious, effortful |
| Everyday decisions | Complex decisions |
| Error-prone | More reliable |
System 1 runs all the time and is usually right. System 2 is lazy: it switches on only when System 1 signals that something is hard. The trouble comes when a problem looks easy but isn’t.
Answer quickly: a bat and a ball cost $1.10 together. The bat costs one dollar more than the ball. How much does the ball cost?
- 10 cents
- 5 cents
- 1 cent
- $1.00
Most people say 10 cents; System 1 offers it instantly. But then the bat would cost $1.10 and the total $1.20. The ball costs 5 cents and the bat $1.05. Even at top universities, most students get this wrong, not because they can’t do the sum, but because the easy answer arrives first and System 2 never checks it.
Five biases that shape decisions
Framing and defaults. Countries next to each other, with similar cultures, show strikingly different rates of consent to organ donation: close to 100% in Austria against about 12% in Germany, and around 86% in Sweden against about 4% in Denmark. The difference isn’t values. It’s the form: in the high countries you are a donor unless you tick a box to opt out; in the low ones you are not a donor unless you tick a box to opt in. How a choice is framed changes the choice.
Anchoring. The first number we hear becomes a reference for everything after it. Ask one group whether a project will take more or less than 2 months, and another whether it will take more or less than 12, then ask both for their estimate: the second group will estimate far longer. Budgets, targets and price negotiations are anchored all the time.
Social proof. If everyone around us does something, we accept it without much critical thought. “This is how the industry works” is social proof, and so are many of the policies TOC challenges, like keeping every machine busy.
Recency. What happened last week feels more important than what happens every week. One dramatic failure drives a new rule, while a quiet recurring problem goes unaddressed.
Commitment and consistency. Once we have said or done something, we bend new evidence to stay consistent with it. The manager who championed a solution is the last to see that it isn’t working.
Exercise: name the bias
- “All our competitors keep three months of stock, so we should too.”
- The supplier opens at ₹500 a unit; after a hard negotiation you agree ₹420 and feel you won.
- After last month’s big customer complaint, every order now needs two sign-offs.
- “We spent two years on this system. It will work once people use it properly.”
- Staff accept a plan described as “saving 200 jobs” but reject the same plan described as “losing 400 jobs”.
Knowing isn’t enough
This is the uncomfortable lesson about bias. Learning about it doesn’t remove it, any more than knowing the lines are equal stops them looking different. What helps is a process: a way of thinking that slows us down at the right moments and makes our reasoning visible, so that others, and we ourselves, can check it. The rest of this course is about that process.
Check your understanding
Answer all five. Get four right to complete the lesson.
1. System 1 thinking is…
- Fast, automatic and error-prone
- Slow, effortful and reliable
- Only used by experts
- Used only for numbers
It runs all the time and is usually right, but not always.
2. Why do so many people get the bat-and-ball question wrong?
- The maths is too hard
- The question is a trick
- The easy answer arrives first and System 2 never checks it
- They don’t know the prices of bats and balls well enough
The problem looks easy, so effortful checking never starts.
3. Organ donation consent differs hugely between similar countries mainly because of…
- Religion
- Income
- Health care quality and trust in hospitals
- The default on the form: opt in or opt out
Framing and defaults shape choices.
4. “Everyone in our industry does it this way” is an example of…
- Anchoring
- Social proof
- Recency
- Deduction
Observed practice accepted without critical thought.
5. What actually protects us from bias?
- Knowing the names of biases
- Trusting our instincts more, since experience usually beats deliberate analysis
- A process that slows us down and makes reasoning checkable
- Deciding faster
Knowing about the illusion doesn’t make it disappear.