Thinking Fast and slow

Daniel Kahneman, 2011.

The two systems

The character of the story

Causal thinking VS Statistical reasoning

Attention and effort

The Lazy controler

The Associative Machine

Cognitive ease



Happiness let us be more intuitive, more creative, letting system I take the lead. Also, we are more prone to error, because of less vigilance

Norms, Surprises, and causes

Assessing Normality

Surprise: When expecting something, something else happens or do not happens. Recurrence lower surprise effect.

Passive vs active expectation

Event appears normal if the pattern has already been seen before.

Moses illusion:

How many animals of each kind did Moses take into the ark ?

Not Moses, Noah. All are mentionend into the Old Testament, so it is not chocking

Seeing Causes and intentions

Inference between action and sub-consequences. Like a billard game.

Need for coherency: If two unrelated thing are on the headlines of the journal, you expect some kind of relationship between.

associative coherence Evoked stuff

impression of causality, that system I generate, which are not a reasoning about causation.

intentional causality: Heider and Simmuel: Associate triangle and circle to people.

Usualy, people takes the soul as the source and cause of the action. TOREAD: Paul Bloom, The Atlantic, 2005. Opposite view, separation between physical and intentional causalities.

A machine for jumping to conclusions

A bias to believe and confirm

Exemple: Ask to remember few digit. Make people read true and fake untrue sentences. With the remembering task, people are better at discerning true from untrue. System II is solicited by the remembering task. If not, System I will stay on place and make mistakes.

Halo Effect, exaggerated Emotional Coherence

Because a people is good on some point, you assume it is good on other unverified point:

Independent jugement, error decorrelation to do

What you see is all there is

How Judgments happen

System II: Asked for a question, will look into the memory and search for answers. It direct his Attention.

System I: Monitor continuously what is going on the world and on the mind, and generate assessments about the situation.

basic assessments are substituted to difficult questions. Translation of values across dimensions.

Basic assessments

How to interact with a stranger. First, you evaluate people dominancy, his trustworthiness, friendly or hostile. Shape of the face let you understand its intentions. Face reading is not perfect, but may help.

When speaking face to face to someone, it is easier to understand intention than in a phone call, than in a written format.

intensity matching

Ranking is easy. Relative Ranking. Giving a grade is less.

Mental shotgun

Some task are easy, but you need to pay attention: counting number of syllables. The control is imprecise, and “we compute much more than we want or need”: mental shotgun

Answering an easier question

Rely on evidence that you cannot explain nor defend.

Substituting Questions

How happy are you these days ?


How many dates did you have last month. How happy are you these days ?

Alone, it is not an easy question. With context, no problem

Affect Heuristic

Likes and dislike shape what we would like to hear / perceive.

System II slow down the thinking of I. Impose logical analysis, self criticism. But do not criticize emotion of I. Search informations and arguments

Heuristic and biases

The Law of Small numbers

Small samples always lead to more frequent extrema appearance.

Random generation doesn’t mean equilibrated distribution. For \(p=1/2\), which is the more frequent:


The science of availability

Availability, Emotion, and Risk

Tom W’s Speciality

Linda: Less is more

Cause Trump Statistics

Regression to the mean

Taming intuitive prediction


The illusion of understanding

The illusion of validity

Traders know about market product and ect. But they are still very bad at predicting the future. But less than newbies.

Individuals tends to be worse, lower thant average than traders.

Intuitions VS Formula

Algorithm do not make error. They always predict the same. They are rigorous.

Expert Intuition: When can we trust it

Intuition is nothing more and nothing else than recognition.

The outside view

The Engine of capitalism


Bernouilli’s Errors

Prospect Theory

The Endowement Effect

Bad events

The fourfold pattern

Rare events

Risk Policies

Keeping Score


Frames and reality

Two selves

Two selves

Life as a story


We remember spikes and ends

Experienced well being

Remember interruption as a break in pleasurable activities.

Positive feelings:

Negative feelings:

Depend on the direct environment (being at the office, people, noise). More focused on the direct activities/event. Best if active than passive (better to do sports than watching TV)

Strong recurrent thoughts instead on direct events sometimes.

Ex: People eating in front of the TV doesn’t appreciate that much the meal.

Salary: There exist a threshold where an increase of salary doesn’t increase the Happiness (75000$ US), and depend on the living area

Experience sampling: Instead of asking to write all the details of your life about a point, a device (phone) vibrate randomly during the day to ask you so (in order to make you think to something else than fulfilling the task).

DRM DAy reconstruction method:

Thinking about life

Mariage is an illusion.

Your happiness in life:

Goals make a large difference

People with goals are going further (in terms of salary if planed)

If you don’t reach your goal, you feel more unhappy, but if you achieve it, you feel happier than average.

Focusing illusion

Speed to answer to question about well being to take into account. Carefull examination ? Too quick answer is just an answer from heuristics, not a “true” one (you will think to recent bad luck event for instance, instead of judging carefully)

Nothing in life is as important as you think it is when you are thinking about it

Also, when thinking about a group (people living in a country with bad weather, paraplegic people), you evaluate their condition. But as they are used to it (like having 2 hands), they don’t really care about.

miswanting When errors are done due to affective forecasting, ie due to current specific short term situation instead of thinking to long term place