Thinking, Fast & Slow (and supplementary articles)
By Daniel Kahneman
Contents
1 Two Systems ................................................................................................................................................ 3
1.1 The characters of the story................................................................................................................. 3
1.2 Attention and effort............................................................................................................................ 3
1.3 The Lazy Controller ............................................................................................................................. 3
1.4 The Associative Machine .................................................................................................................... 3
1.5 Cognitive Ease ..................................................................................................................................... 4
1.6 Norms, Surprises, and Causes ............................................................................................................ 4
1.7 A Machine for Jumping to Conclusions ............................................................................................. 4
1.8 How Judgements Happen .................................................................................................................. 5
1.9 Answering an Easier Question ............................................................................................................ 5
2 Heuristics and Biases ................................................................................................................................... 5
2.10 The Law of Small Numbers ................................................................................................................. 5
2.11 Anchors ................................................................................................................................................ 5
2.12 The Science of Availability .................................................................................................................. 6
2.13 Availability, Emotion, and Risk ........................................................................................................... 6
2.14 Tom W’s Specialty ............................................................................................................................... 6
2.15 Linda: Less is More .............................................................................................................................. 6
2.16 Causes Trump Statistics ...................................................................................................................... 6
2.17 Regression to the Mean...................................................................................................................... 7
2.18 Taming Intuitive Predictions ............................................................................................................... 7
3 Overconfidence ........................................................................................................................................... 7
3.19 The Illusion of Understanding ............................................................................................................ 7
3.20 The Illusion of Validity ......................................................................................................................... 7
3.21 Intuitions Vs. Formulas ....................................................................................................................... 8
3.22 Expert Intuition: When Can We Trust It?............................................................................................ 8
3.23 The Outside View ................................................................................................................................ 8
3.24 The Engine of Capitalism .................................................................................................................... 8
4 Choices ......................................................................................................................................................... 8
4.25 Bernoulli’s Errors ................................................................................................................................. 8
, 4.26 Prospect Theory ................................................................................................................................. 9
4.27 The Endowment Effect ....................................................................................................................... 9
4.28 Bad Events ........................................................................................................................................... 9
4.29 The fourfold pattern .......................................................................................................................... 9
4.30 Rare events.......................................................................................................................................... 9
4.31 Risk Policies ....................................................................................................................................... 10
4.32 Keeping Score ................................................................................................................................... 10
4.33 Reversals............................................................................................................................................ 10
4.34 Frames and Reality ............................................................................................................................ 10
5 Two Selves .................................................................................................................................................. 11
5.35 Two Selves .......................................................................................................................................... 11
5.36 Life as a Story ..................................................................................................................................... 11
5.37 Experienced Well-Being ..................................................................................................................... 11
5.38 Thinking About Life ............................................................................................................................ 11
Overview System 1 .............................................................................................................................................. 11
Judgement under Uncertainty: Heuristics and Biases (1974) ...........................................................................13
Representativeness ........................................................................................................................................13
Availability .......................................................................................................................................................13
Adjustment and Anchoring ........................................................................................................................... 14
Constructive Consumer Choice Processes (1998) ............................................................................................ 14
Consumer Decision Tasks and Decision Strategies .......................................................................................15
Choices, Values, and Frames (1983) ...................................................................................................................15
Risky Choice ................................................................................................................................................... 16
Transactions and Trades ............................................................................................................................... 16
Concluding remarks ........................................................................................................................................17
The MPG Illusion (2008) .....................................................................................................................................17
Do Defaults Save Lives? ......................................................................................................................................17
Nudge Your Customers Toward Better Choices (2008) .................................................................................. 18
Mass Defaults ................................................................................................................................................ 18
Personalized Defaults .................................................................................................................................... 18
, 1 Two Systems
1.1 The characters of the story
There are two systems that are used when thinking. System 1 operates automatically and quickly with little
to no effort and no sense of voluntary control. System 2 allocates attention to the effortful mental activities
that demand it, including complex computations. System 2 has some ability to change the way system 1
works, by programming the normally automatic functions of attention and the memory. Intense focusing
on a task can make people effectively blind, even to stimuli that normally attract attention (the invisible
gorilla).
An interplay between system 1 and system 2 takes place. System 1 generates suggestions for system 2,
system 2 steps in where system 1 runs into difficulties. System 2 is activated when an event is detected that
violates the model of the world that system 1 maintains. In summary, most of what you do and think
originates in system 1, but system 2 takes over when things get difficult, and it normally has the last word.
A conflict between an automatic reaction and an intention to control arises when system 2 is to overcome
the impulses of system 1. System 2 is in charge of self-control.
Knowing that something is an illusion does not help you to ‘see’ the illusion (Müller-Lyer illusion). This is
because system 1 acts automatically. An example of an illusion is a cognitive illusion.
1.2 Attention and effort
Pupil dilation is influenced by mental effort, attention and attraction. System 1 takes over in emergencies
and assigns total priority to self-protective actions. The law of least effort states that people will eventually
gravitate towards the least demanding course of action. Effort is required to maintain simultaneously in
memory several ideas that require separate actions, or that need to be combined according to a rule. A
crucial capability of system 2 is the adoption of “task sets”: it can program memory to obey an instruction
that overrides habitual responses. Effort is required when switching between tasks and under time-
pressure.
1.3 The Lazy Controller
System 2 has a natural speed. Cognitive work is often perceived as unpleasurable. Except for when in a
state of ‘flow’, then one is effortless attending. It is described as a state of effortless concentration, so deep
that one loses their sense of time, of oneself, and of ones problems.
People who are cognitively busy are more likely to yield to temptation, make selfish choices, use sexist
language and make superficial judgements. Controlling thoughts and behaviours is one of the tasks that
system 2 performs. An effort of will or self-control is tiring, this is seen in ego depletion. It will lead to faster
giving up and caused by a drop in glucose-levels.
If system 1 is involved, the conclusion comes first and the arguments follow. Often system 2 is “too lazy”
to correct system 1 when an error is made. People who rely on system 1 are more impulsive, impatient, ad
keen to receive immediate gratification. System 2 is capable of reasoning, and it is cautious, but at least for
some people, it is also lazy.
1.4 The Associative Machine
Associative activation is a process that takes place when ideas that have been evoked trigger many other
ideas, in a spreading cascade of activity in your brain. This happens quickly and all at once, yielding a self-
By Daniel Kahneman
Contents
1 Two Systems ................................................................................................................................................ 3
1.1 The characters of the story................................................................................................................. 3
1.2 Attention and effort............................................................................................................................ 3
1.3 The Lazy Controller ............................................................................................................................. 3
1.4 The Associative Machine .................................................................................................................... 3
1.5 Cognitive Ease ..................................................................................................................................... 4
1.6 Norms, Surprises, and Causes ............................................................................................................ 4
1.7 A Machine for Jumping to Conclusions ............................................................................................. 4
1.8 How Judgements Happen .................................................................................................................. 5
1.9 Answering an Easier Question ............................................................................................................ 5
2 Heuristics and Biases ................................................................................................................................... 5
2.10 The Law of Small Numbers ................................................................................................................. 5
2.11 Anchors ................................................................................................................................................ 5
2.12 The Science of Availability .................................................................................................................. 6
2.13 Availability, Emotion, and Risk ........................................................................................................... 6
2.14 Tom W’s Specialty ............................................................................................................................... 6
2.15 Linda: Less is More .............................................................................................................................. 6
2.16 Causes Trump Statistics ...................................................................................................................... 6
2.17 Regression to the Mean...................................................................................................................... 7
2.18 Taming Intuitive Predictions ............................................................................................................... 7
3 Overconfidence ........................................................................................................................................... 7
3.19 The Illusion of Understanding ............................................................................................................ 7
3.20 The Illusion of Validity ......................................................................................................................... 7
3.21 Intuitions Vs. Formulas ....................................................................................................................... 8
3.22 Expert Intuition: When Can We Trust It?............................................................................................ 8
3.23 The Outside View ................................................................................................................................ 8
3.24 The Engine of Capitalism .................................................................................................................... 8
4 Choices ......................................................................................................................................................... 8
4.25 Bernoulli’s Errors ................................................................................................................................. 8
, 4.26 Prospect Theory ................................................................................................................................. 9
4.27 The Endowment Effect ....................................................................................................................... 9
4.28 Bad Events ........................................................................................................................................... 9
4.29 The fourfold pattern .......................................................................................................................... 9
4.30 Rare events.......................................................................................................................................... 9
4.31 Risk Policies ....................................................................................................................................... 10
4.32 Keeping Score ................................................................................................................................... 10
4.33 Reversals............................................................................................................................................ 10
4.34 Frames and Reality ............................................................................................................................ 10
5 Two Selves .................................................................................................................................................. 11
5.35 Two Selves .......................................................................................................................................... 11
5.36 Life as a Story ..................................................................................................................................... 11
5.37 Experienced Well-Being ..................................................................................................................... 11
5.38 Thinking About Life ............................................................................................................................ 11
Overview System 1 .............................................................................................................................................. 11
Judgement under Uncertainty: Heuristics and Biases (1974) ...........................................................................13
Representativeness ........................................................................................................................................13
Availability .......................................................................................................................................................13
Adjustment and Anchoring ........................................................................................................................... 14
Constructive Consumer Choice Processes (1998) ............................................................................................ 14
Consumer Decision Tasks and Decision Strategies .......................................................................................15
Choices, Values, and Frames (1983) ...................................................................................................................15
Risky Choice ................................................................................................................................................... 16
Transactions and Trades ............................................................................................................................... 16
Concluding remarks ........................................................................................................................................17
The MPG Illusion (2008) .....................................................................................................................................17
Do Defaults Save Lives? ......................................................................................................................................17
Nudge Your Customers Toward Better Choices (2008) .................................................................................. 18
Mass Defaults ................................................................................................................................................ 18
Personalized Defaults .................................................................................................................................... 18
, 1 Two Systems
1.1 The characters of the story
There are two systems that are used when thinking. System 1 operates automatically and quickly with little
to no effort and no sense of voluntary control. System 2 allocates attention to the effortful mental activities
that demand it, including complex computations. System 2 has some ability to change the way system 1
works, by programming the normally automatic functions of attention and the memory. Intense focusing
on a task can make people effectively blind, even to stimuli that normally attract attention (the invisible
gorilla).
An interplay between system 1 and system 2 takes place. System 1 generates suggestions for system 2,
system 2 steps in where system 1 runs into difficulties. System 2 is activated when an event is detected that
violates the model of the world that system 1 maintains. In summary, most of what you do and think
originates in system 1, but system 2 takes over when things get difficult, and it normally has the last word.
A conflict between an automatic reaction and an intention to control arises when system 2 is to overcome
the impulses of system 1. System 2 is in charge of self-control.
Knowing that something is an illusion does not help you to ‘see’ the illusion (Müller-Lyer illusion). This is
because system 1 acts automatically. An example of an illusion is a cognitive illusion.
1.2 Attention and effort
Pupil dilation is influenced by mental effort, attention and attraction. System 1 takes over in emergencies
and assigns total priority to self-protective actions. The law of least effort states that people will eventually
gravitate towards the least demanding course of action. Effort is required to maintain simultaneously in
memory several ideas that require separate actions, or that need to be combined according to a rule. A
crucial capability of system 2 is the adoption of “task sets”: it can program memory to obey an instruction
that overrides habitual responses. Effort is required when switching between tasks and under time-
pressure.
1.3 The Lazy Controller
System 2 has a natural speed. Cognitive work is often perceived as unpleasurable. Except for when in a
state of ‘flow’, then one is effortless attending. It is described as a state of effortless concentration, so deep
that one loses their sense of time, of oneself, and of ones problems.
People who are cognitively busy are more likely to yield to temptation, make selfish choices, use sexist
language and make superficial judgements. Controlling thoughts and behaviours is one of the tasks that
system 2 performs. An effort of will or self-control is tiring, this is seen in ego depletion. It will lead to faster
giving up and caused by a drop in glucose-levels.
If system 1 is involved, the conclusion comes first and the arguments follow. Often system 2 is “too lazy”
to correct system 1 when an error is made. People who rely on system 1 are more impulsive, impatient, ad
keen to receive immediate gratification. System 2 is capable of reasoning, and it is cautious, but at least for
some people, it is also lazy.
1.4 The Associative Machine
Associative activation is a process that takes place when ideas that have been evoked trigger many other
ideas, in a spreading cascade of activity in your brain. This happens quickly and all at once, yielding a self-
