PSYC 180 Thinking Fast and Slow
Thinking, Fast and Slow
Your pupils dilate when working on a problem
System 1 and system 2:
o System 1 operates automatically and quickly, with little or no effort and no sense of
o System 2 allocates attention to the effortful mental activities that demand it, including
complex computations. Often associated with the subjective experience of agency, choice
We can be blind to the obvious, and we are also blind to our blindness.
System 1 has biases: systematic errors it is prone to make in specified circumstances. It
sometimes answers easier questions than the one it was asked, and it has little understanding of
logic and statistics. It also cannot be turned off.
One task of system 2 is to overcome the impulses of system 1 it is in charge of self-control.
Cognitive illusions: illusions of thought e.g. a patient with a repeated history of failed treatment is
a danger sign; system 2 has learned to recognize this situation and not to act on it (not feel
sympathy towards the patient).
Pupils are sensitive indicators of mental effort they dilate more if problems are hard than easy.
The response to mental effort is distinct from emotional arousal.
As you become skilled in a task, its demand for energy diminishes.
The law of least effort if there are several ways of achieving the same goal, people will
gravitate to the least demanding course of action.
Flow: a state of effortless concentration so deep that they lose their sense of time, of themselves,
of their problems. Flow separates the two forms of effort: concentration on the task and the
control of attention.
Being cognitively busy can make system 1 have more influence on behaviour and can make
people more likely to make selfish choices, use sexist language, and make superficial judgements
in social situations.
Ego depletion: an effort of will or self-control is tiring if you had to force yourself to do
something, you are less willing to exert self-control when the next challenge comes around.
The effects of ego depletion could be undone by ingesting glucose. This is why judges are more
likely to approve parole requests after a meal.
Rationality should be distinguished from intelligences. Superficial or lazy thinking is a failure
Associatively coherent: a pattern of cognitive, emotional and physical responses from a stimulus.
The priming effect: the idea of eat primes the idea of soup. This effect is no limited to only
concepts and words it can affect our actions, without out awareness.
o The ideomotor effect: priming phenomenon the influence of an action by an idea.
o Money-primed people are more independent and selfish less likely to help others.
Illusion of remembering: seeing a name makes it easier to identify that name if you see it later.
You experience greater cognitive ease in perceiving a word you have seen earlier, and this gives
you the impression of familiarity. PSYC 180 Thinking Fast and Slow
Predictable illusions inevitably occur if a judgement is based on an impression of cognitive ease
Truth illusions: seeing a familiar sentence in a phrase will make you more likely to believe the
Cognitive strain mobilizes system 2, which is more likely to reject the intuitive answer suggested
by system 1.
The mere exposure effect: link between the repetition of an arbitrary stimulus and the mild
affection that people eventually have for it. Stronger effect for stimuli that the individual never
Cognitive ease plays a role in judgement; mood has an effect on intuitive performance when we
are unhappy, we lose touch with our intuition.
Norm theory: how events come to be perceived as normal or abnormal. Events appear normal
because they have happened before.
Our need for coherence: a large event is supposed to have consequences, and consequences need
causes to explain them. Thus system 1 finds a coherent causal story that links fragments of
Illusion of causality: the observers know there is no real physical contact on a demonstration,
but they describe it as being caused by an action.
Recent events and the current context have the most weight in determining an interpretation.
The operations of associative memory contribute to confirmation bias: different memories will
come to mind when asked is Sam friendly? instead of when asked is Sam unfriendly?
Positive test strategy: search for confirming evidence to test a hypothesis. This is contrary to
science you should try to refute hypotheses while testing them.
The halo effect: the tendency to like or dislike everything about a person including things you
have not observed. It is a common bias that plays a large role in shaping our view of people and
situations. This effect increases the weight of first impressions.
What you see is all there is: WYSIATI. Jumping to conclusions on the basis of limited evidence.
It facilitates the achievement of coherence and of the cognitive ease that causes us to accept a
statement as true. But biases of judgement and choice as a consequence:
o Overconfidence (based only on what they see and not what is missing)
o Framing effects: different ways of presenting the same information often evoke different
emotions. (90% fat-free vs. 10% fat)
o Base-rate neglect: Steve often believed to be a librarian, but there are more male farmers
Basic assessment: situations are constantly being evaluated good mood and cognitive ease.
System 1 represents categories by a prototype or a set of typical exemplars. Thus it deals well
with averages but not sums. The size of the category, the number of instances it contains, tends to
be ignored in judgements of sum-like variables.
The mental shotgun: we often compute much more than we want or need. It is impossible to aim
at a single point with a shotgun because it shoots pellets that scatter, so its difficult for system 1
not to do more than it is supposed to.
Substitution: answering one question (that is easier to answer) in place of another.
o The target question is the assessment you intend to produce
o The heuristic question is the simpler question that you answer instead.PSYC 180 Thinking Fast and Slow
System 1 is capable of intensity matching: e.g. matching crime to intensity of colour.
A judgement that is based on substitution will inevitably be biased in predictable ways
Affect heuristic: people let their likes and dislikes determine their beliefs about the world.
Small samples yield more extreme results than large samples. Large samples are more precise
than small samples.
Even experts pay insufficient attention to sample size.
Bias towards believing that small samples closely resemble the population from which they are
drawn. We are also prone to exaggerate the consistency and coherence of what we see.
We see patterns where none exists. E.g. there is no such thing as a hot hand in sports such as
basketball. The hot hand is a cognitive illusion.
The anchoring effect: occurs when people consider a particular value for an unknown quantity
before estimating that quantity. The estimates stay close to the number the people considered:
the anchor. Peoples judgements are influenced by an obviously uninformative number.
Two different mechanisms produce anchoring effects one for each system. One form occurs in a
deliberate process of adjustment (system 2) and another occurs by a priming effect (system 1).
o Adjustment: start from an anchoring number and gradually adjust your estimate by
mentally moving from the anchor. But the adjustment typically ends prematurely
because people stop when they are no longer certain that they should move farther
o Priming: anchoring is a case of suggestion when someone causes us to hear or feel