''Thinking, Fast and Slow'' is a 2011 popular science book by psychologist
Daniel Kahneman
Daniel Kahneman (; ; March 5, 1934 – March 27, 2024) was an Israeli-American psychologist best known for his work on the psychology of judgment and decision-making as well as behavioral economics, for which he was awarded the 2002 Nobel Memor ...
.
The book's main thesis is a differentiation between two modes of
thought
In their most common sense, the terms thought and thinking refer to cognitive processes that can happen independently of sensory stimulation. Their most paradigmatic forms are judging, reasoning, concept formation, problem solving, and de ...
: "System 1" is fast,
instinct
Instinct is the inherent inclination of a living organism towards a particular complex behaviour, containing innate (inborn) elements. The simplest example of an instinctive behaviour is a fixed action pattern (FAP), in which a very short to me ...
ive and
emotion
Emotions are physical and mental states brought on by neurophysiology, neurophysiological changes, variously associated with thoughts, feelings, behavior, behavioral responses, and a degree of pleasure or suffering, displeasure. There is ...
al; "System 2" is slower, more
deliberative
Deliberative may refer to:
*Deliberative agent
*Deliberative assembly
*Deliberative Council of Princes and Ministers
*Deliberative democracy
*Deliberative mood
*Deliberative opinion poll
*Deliberative planning
*Deliberative process privilege
*Deli ...
, and more
logic
Logic is the study of correct reasoning. It includes both formal and informal logic. Formal logic is the study of deductively valid inferences or logical truths. It examines how conclusions follow from premises based on the structure o ...
al.
The book delineates rational and non-rational motivations or triggers associated with each type of thinking process, and how they complement each other, starting with Kahneman's own research on
loss aversion
In cognitive science and behavioral economics, loss aversion refers to a cognitive bias in which the same situation is perceived as worse if it is framed as a loss, rather than a gain. It should not be confused with risk aversion, which descri ...
. From
framing choices to people's tendency to replace a difficult question with one that is easy to answer, the book summarizes several decades of research to suggest that people have too much confidence in human judgment. Kahneman performed his own research, often in collaboration with
Amos Tversky
Amos Nathan Tversky (; March 16, 1937 – June 2, 1996) was an Israeli cognitive and mathematical psychologist and a key figure in the discovery of systematic human cognitive bias and handling of risk.
Much of his early work concerned th ...
, which enriched his experience to write the book.
It covers different phases of his career: his early work concerning
cognitive bias
A cognitive bias is a systematic pattern of deviation from norm (philosophy), norm or rationality in judgment. Individuals create their own "subjective reality" from their perception of the input. An individual's construction of reality, not the ...
es, his work on
prospect theory
Prospect theory is a theory of behavioral economics, judgment and decision making that was developed by Daniel Kahneman and Amos Tversky in 1979. The theory was cited in the decision to award Kahneman the 2002 Nobel Memorial Prize in Economics. ...
and
happiness
Happiness is a complex and multifaceted emotion that encompasses a range of positive feelings, from contentment to intense joy. It is often associated with positive life experiences, such as achieving goals, spending time with loved ones, ...
, and with the
Israel Defense Forces
The Israel Defense Forces (IDF; , ), alternatively referred to by the Hebrew-language acronym (), is the national military of the State of Israel. It consists of three service branches: the Israeli Ground Forces, the Israeli Air Force, and ...
.
Jason Zweig, a columnist at The Wall Street Journal, helped write and research the book over two years. The book was a
''New York Times'' bestseller and was the 2012 winner of the
National Academies Communication Award for best creative work that helps the public understanding of topics in
behavioral science
Behavioural science is the branch of science concerned with Human behavior, human behaviour.Hallsworth, M. (2023). A manifesto for applying behavioural science. ''Nature Human Behaviour'', ''7''(3), 310-322. While the term can technically be ap ...
, engineering and medicine.
[ The integrity of some priming studies cited in the book has been called into question in the midst of the psychological ]replication crisis
The replication crisis, also known as the reproducibility or replicability crisis, refers to the growing number of published scientific results that other researchers have been unable to reproduce or verify. Because the reproducibility of empir ...
.
Two systems
In the book's first section, Kahneman describes two different ways the brain forms thoughts:
* System 1: Fast, automatic, frequent, emotional, stereotypic, unconscious. Examples (in order of complexity) of things system 1 can do:
** determine that an object is at a greater distance than another
** localize the source of a specific sound
** complete the phrase "war and ..."
** display disgust when seeing a gruesome image
** solve 2 + 2 = ?
** read text on a billboard
** drive a car on an empty road
** think of a good chess move (if you're a chess master)
** understand simple sentences
* System 2: Slow, effortful, infrequent, logical, calculating, conscious. Examples of things system 2 can do:
** prepare yourself for the start of a sprint
** direct your attention towards the clowns at the circus
** direct your attention towards someone at a loud party
** look for the woman with the grey hair
** try to recognize a sound
** sustain a faster-than-normal walking rate
** determine the appropriateness of a particular behavior in a social setting
** count the number of A's in a certain text
** give someone your telephone number
** park into a tight parking space
** determine the price/quality ratio of two washing machines
** determine the validity of a complex logical reasoning
** solve 17 × 24
Kahneman describes a number of experiments which purport to examine the differences between these two thought systems and how they arrive at different results even given the same inputs. Terms and concepts include coherence, attention, laziness, association, jumping to conclusions, WYSIATI (What you see is all there is), and how one forms judgments. The System 1 vs. System 2 debate includes the reasoning or lack thereof for human decision making, with big implications for many areas including law and market research.
Heuristics and biases
The second section offers explanations for why humans struggle to think statistically. It begins by documenting a variety of situations in which we either arrive at binary decisions or fail to associate precisely reasonable probabilities with outcomes. Kahneman explains this phenomenon using the theory of heuristics
A heuristic or heuristic technique (''problem solving'', '' mental shortcut'', ''rule of thumb'') is any approach to problem solving that employs a pragmatic method that is not fully optimized, perfected, or rationalized, but is nevertheless ...
. Kahneman and Tversky originally discussed this topic in their 1974 article titled Judgment Under Uncertainty: Heuristics and Biases.
Kahneman uses heuristics to assert that System 1 thinking involves associating new information with existing patterns, or thoughts, rather than creating new patterns for each new experience. For example, a child who has only seen shapes with straight edges might perceive an octagon when first viewing a circle. As a legal metaphor, a judge limited to heuristic thinking would only be able to think of similar historical cases when presented with a new dispute, rather than considering the unique aspects of that case. In addition to offering an explanation for the statistical problem, the theory also offers an explanation for human biases.
Anchoring
The "anchoring effect" names a tendency to be influenced by irrelevant numbers. Shown greater/lesser numbers, experimental subjects gave greater/lesser responses. As an example, most people, when asked whether Gandhi
Mohandas Karamchand Gandhi (2October 186930January 1948) was an Indian lawyer, anti-colonial nationalist, and political ethicist who employed nonviolent resistance to lead the successful campaign for India's independence from British ...
was more than 114 years old when he died, will provide a much greater estimate of his age at death than others who were asked whether Gandhi was more or less than 35 years old. Experiments show that people's behavior is influenced, much more than they are aware, by irrelevant information.
Availability
The availability heuristic is a mental shortcut that occurs when people make judgments about the probability of events on the basis of how easy it is to think of examples. The availability heuristic operates on the notion that, "if you can think of it, it must be important". The availability of consequences associated with an action is related positively to perceptions of the magnitude of the consequences of that action. In other words, the easier it is to recall the consequences of something, the greater we perceive these consequences to be. Sometimes, this heuristic is beneficial, but the frequencies at which events come to mind are usually not accurate representations of the probabilities of such events in real life.
Conjunction fallacy
System 1 is prone to substituting a simpler question for a difficult one. In what Kahneman terms their "best-known and most controversial" experiment, "the Linda problem", subjects were told about an imaginary Linda, young, single, outspoken, and intelligent, who, as a student, was very concerned with discrimination and social justice. They asked whether it was more probable that Linda is a bank teller or that she is a bank teller and an active feminist. The overwhelming response was that "feminist bank teller" was more likely than "bank teller", violating the laws of probability
Probability is a branch of mathematics and statistics concerning events and numerical descriptions of how likely they are to occur. The probability of an event is a number between 0 and 1; the larger the probability, the more likely an e ...
. (All feminist bank tellers are bank tellers, so the former can't be more likely). In this case System 1 substituted the easier question, "Is Linda a feminist?", neglecting the occupation qualifier. An alternative interpretation is that the subjects added an unstated cultural implicature
In pragmatics, a subdiscipline of linguistics, an implicature is something the speaker suggests or implies with an utterance, even though it is not literally expressed. Implicatures can aid in communicating more efficiently than by explicitly sayi ...
to the effect that the other answer implied an exclusive or
Exclusive or, exclusive disjunction, exclusive alternation, logical non-equivalence, or logical inequality is a logical operator whose negation is the logical biconditional. With two inputs, XOR is true if and only if the inputs differ (on ...
, that Linda was not a feminist.
Optimism and loss aversion
Kahneman writes of a "pervasive optimistic bias", which "may well be the most significant of the cognitive biases." This bias generates the illusion of control
The illusion of control is the tendency for people to overestimate their ability to control events. It was named by U.S. psychologist Ellen Langer and is thought to influence gambling behavior and belief in the paranormal. Along with illusory sup ...
: the illusion that we have substantial control of our lives.
A natural experiment reveals the prevalence of one kind of unwarranted optimism. The planning fallacy is the tendency to overestimate benefits and underestimate costs, impelling people to begin risky projects. In 2002, American kitchen remodeling was expected on average to cost $18,658, but actually cost $38,769.
To explain overconfidence, Kahneman introduces the concept he terms ''What You See Is All There Is'' (WYSIATI). This theory states that when the mind makes decisions, it deals primarily with ''Known Knowns'', phenomena it has observed already. It rarely considers ''Known Unknowns'', phenomena that it knows to be relevant but about which it does not have information. Finally it appears oblivious to the possibility of ''Unknown Unknowns'', unknown phenomena of unknown relevance.
He explains that humans fail to take into account complexity and that their understanding of the world consists of a small and necessarily un-representative set of observations. Furthermore, the mind generally does not account for the role of chance and therefore falsely assumes that a future event will be similar to a past event.
Framing
Framing is the context in which choices are presented. Experiment: subjects were asked whether they would opt for surgery if the "survival" rate is 90 percent, while others were told that the mortality rate is 10 percent. The first framing increased acceptance, even though the situation was no different.
Sunk cost
Rather than consider the odds that an incremental investment would produce a positive return, people tend to "throw good money after bad" and continue investing in projects with poor prospects that have already consumed significant resources. In part this is to avoid feelings of regret.
Overconfidence
This part (part III, sections 19–24) of the book is dedicated to the undue confidence in what the mind believes it knows. It suggests that people often overestimate how much they understand about the world and underestimate the role of chance in particular. This is related to the excessive certainty of hindsight, when an event seems to be understood after it has occurred or developed. Kahneman's opinions concerning overconfidence are influenced by Nassim Nicholas Taleb
Nassim Nicholas Taleb (; alternatively ''Nessim ''or'' Nissim''; born 12 September 1960) is a Lebanese-American essayist, mathematical statistician, former option trader, risk analyst, and aphorist. His work concerns problems of randomness, ...
.
Choices
In this section Kahneman returns to economics and expands his seminal work on Prospect Theory. He discusses the tendency for problems to be addressed in isolation and how, when other reference points are considered, the choice of that reference point (called a frame) has a disproportionate effect on the outcome. This section also offers advice on how some of the shortcomings of System 1 thinking can be avoided.
Prospect theory
Kahneman developed prospect theory, the basis for his Nobel prize, to account for experimental errors he noticed in Daniel Bernoulli
Daniel Bernoulli ( ; ; – 27 March 1782) was a Swiss people, Swiss-France, French mathematician and physicist and was one of the many prominent mathematicians in the Bernoulli family from Basel. He is particularly remembered for his applicati ...
's traditional utility theory
In economics, utility is a measure of a certain person's satisfaction from a certain state of the world. Over time, the term has been used with at least two meanings.
* In a Normative economics, normative context, utility refers to a goal or ob ...
. According to Kahneman, Utility Theory makes logical assumptions of economic rationality that do not represent people's actual choices, and does not take into account cognitive biases
A cognitive bias is a systematic pattern of deviation from norm or rationality in judgment. Individuals create their own "subjective reality" from their perception of the input. An individual's construction of reality, not the objective input, ...
.
One example is that people are loss-averse: they are more likely to act to avert a loss than to achieve a gain. Another example is that the value people place on a change in probability (e.g., of winning something) depends on the reference point: people seem to place greater value on a change from 0% to 10% (going from impossibility to possibility) than from, say, 45% to 55%, and they place the greatest value of all on a change from 90% to 100% (going from possibility to certainty). This occurs despite the fact that by traditional utility theory all three changes give the same increase in utility. Consistent with loss-aversion, the order of the first and third of those is reversed when the event is presented as losing rather than winning something: there, the greatest value is placed on eliminating the probability of a loss to 0.
After the book's publication, the ''Journal of Economic Literature
The ''Journal of Economic Literature'' is a peer-reviewed academic journal, published by the American Economic Association, that surveys the academic literature in economics. It was established by Arthur Smithies in 1963 as the ''Journal of Econo ...
'' published a discussion of its parts concerning prospect theory, as well as an analysis of the four fundamental factors on which it is based.
Two selves
The fifth part of the book describes recent evidence which introduces a distinction between two selves, the 'experiencing self' and 'remembering self'. Kahneman proposed an alternative measure that assessed pleasure or pain sampled from moment to moment, and then summed over time. Kahneman termed this "experienced" well-being and attached it to a separate "self". He distinguished this from the "remembered" well-being that the polls had attempted to measure. He found that these two measures of happiness diverged.
Life as a story
The author's significant discovery was that the remembering self does not care about the duration of a pleasant or unpleasant experience. Instead, it retrospectively rates an experience by the maximum or minimum of the experience, and by the way it ends. The remembering self dominated the patient's ultimate conclusion.
Experienced well-being
Kahneman first began the study of well-being in the 1990s. At the time most happiness research relied on polls about life satisfaction
Life satisfaction is an evaluation of a person's quality of life. It is assessed in terms of mood, relationship satisfaction, achieved goals, self-concepts, and the self-perceived ability to cope with life. Life satisfaction involves a favorabl ...
. Having previously studied unreliable memories, the author was doubtful that life satisfaction was a good indicator of happiness. He designed a question that emphasized instead the well-being of the experiencing self. The author proposed that "Helen was happy in the month of March" if she spent most of her time engaged in activities that she would rather continue than stop, little time in situations that she wished to escape, and not too much time in a neutral state that wouldn't prefer continuing or stopping the activity either way.
Thinking about life
Kahneman suggests that emphasizing a life event such as a marriage or a new car can provide a distorted illusion of its true value. This "focusing illusion The focusing illusion is a cognitive bias where individuals overestimate the impact of a specific factor on their overall happiness. This leads people to believe that changes such as a promotion, an increase in income, or moving to a more desirable ...
" revisits earlier ideas of substituting difficult questions and WYSIATI.
Awards and honors
* 2011 Los Angeles Times Book Prize
Since 1980, the ''Los Angeles Times'' has awarded a set of annual book prizes. The ''Los Angeles Times'' Book Prize currently has nine categories: biography, current interest, fiction, first fiction (the Art Seidenbaum Award added in 1991), his ...
(Current Interest)
* National Academy of Sciences Best Book Award in 2012
* ''The New York Times Book Review
''The New York Times Book Review'' (''NYTBR'') is a weekly paper-magazine supplement to the Sunday edition of ''The New York Times'' in which current non-fiction and fiction books are reviewed. It is one of the most influential and widely rea ...
'', one of the best books of 2011
* Globe and Mail Best Books of the Year 2011
* One of ''The Economist
''The Economist'' is a British newspaper published weekly in printed magazine format and daily on Electronic publishing, digital platforms. It publishes stories on topics that include economics, business, geopolitics, technology and culture. M ...
s 2011 Books of the Year
* One of ''The Wall Street Journal
''The Wall Street Journal'' (''WSJ''), also referred to simply as the ''Journal,'' is an American newspaper based in New York City. The newspaper provides extensive coverage of news, especially business and finance. It operates on a subscriptio ...
s Best Nonfiction Books of the Year 2011
Reception
As of 2012 the book had sold over one million copies. On the year of its publication, it was on the New York Times Bestseller List
''The New York Times'' Best Seller list is widely considered the preeminent list of best-selling books in the United States. John Bear, ''The #1 New York Times Best Seller: intriguing facts about the 484 books that have been #1 New York Times ...
.[ The book was reviewed in media including the '']Huffington Post
''HuffPost'' (''The Huffington Post'' until 2017, itself often abbreviated as ''HPo'') is an American progressive news website, with localized and international editions. The site offers news, satire, blogs, and original content, and covers ...
'', ''The Guardian
''The Guardian'' is a British daily newspaper. It was founded in Manchester in 1821 as ''The Manchester Guardian'' and changed its name in 1959, followed by a move to London. Along with its sister paper, ''The Guardian Weekly'', ''The Guardi ...
'', ''The New York Times
''The New York Times'' (''NYT'') is an American daily newspaper based in New York City. ''The New York Times'' covers domestic, national, and international news, and publishes opinion pieces, investigative reports, and reviews. As one of ...
'', ''The Financial Times
The ''Financial Times'' (''FT'') is a British daily newspaper printed in broadsheet and also published digitally that focuses on business and economic Current affairs (news format), current affairs. Based in London, the paper is owned by a Jap ...
'', ''The Independent
''The Independent'' is a British online newspaper. It was established in 1986 as a national morning printed paper. Nicknamed the ''Indy'', it began as a broadsheet and changed to tabloid format in 2003. The last printed edition was publis ...
'', ''Bloomberg
Bloomberg may refer to:
People
* Daniel J. Bloomberg (1905–1984), audio engineer
* Georgina Bloomberg (born 1983), professional equestrian
* Michael Bloomberg (born 1942), American businessman and founder of Bloomberg L.P.; politician a ...
'' and ''The New York Review of Books
''The New York Review of Books'' (or ''NYREV'' or ''NYRB'') is a semi-monthly magazine with articles on literature, culture, economics, science and current affairs. Published in New York City, it is inspired by the idea that the discussion of ...
''. On Book Marks
''Literary Hub'' or ''LitHub'' is a daily literary website that was launched in 2015 by Grove Atlantic president and publisher Morgan Entrekin, American Society of Magazine Editors Hall of Fame editor Terry McDonell, and '' Electric Literatur ...
, the book received a "rave" consensus, based on eight critic reviews: six "rave" and two "positive". ''Prosenotes'' gave it a "C" (72%) based on critic reviews with a consensus saying, "On the whole it is an important, readable, and interesting book about judgment and decision making, but even some of the author's diehard fans found small portions of this book hard to work through". In March/April 2012 issue of Bookmarks, the book received a (4.00 out of 5) with the critical summary stating, "Either way, it's an enlightening tome on how--fast or slow--we make decisions".
The book was also widely reviewed in academic journals, including the ''Journal of Economic Literature
The ''Journal of Economic Literature'' is a peer-reviewed academic journal, published by the American Economic Association, that surveys the academic literature in economics. It was established by Arthur Smithies in 1963 as the ''Journal of Econo ...
'',[ '']American Journal of Education
''The American Journal of Education'' seeks to bridge and integrate the intellectual, methodological, and substantive diversity of educational scholarship and to encourage a vigorous dialogue between educational scholars and policy makers. It publ ...
'', ''The American Journal of Psychology
The ''American Journal of Psychology'' is a journal devoted primarily to experimental psychology. It is the first such journal to be published in the English language (though ''Mind'', founded in 1876, published some experimental psychology earl ...
'', '' Planning Theory'', '' The American Economist'', '' The Journal of Risk and Insurance'', '' The Michigan Law Review'', ''American Scientist
''American Scientist'' (informally abbreviated ''AmSci'') is an American bimonthly science and technology magazine published since 1913 by Sigma Xi, The Scientific Research Honor Society. In the beginning of 2000s the headquarters was moved to ...
'', ''Contemporary Sociology
''Contemporary Sociology'' is a bi-monthly peer-reviewed academic journal of sociology published by SAGE Publications in association with the American Sociological Association since 1972. Each issue of the journal publishes many in-depth as well as ...
'', ''Science
Science is a systematic discipline that builds and organises knowledge in the form of testable hypotheses and predictions about the universe. Modern science is typically divided into twoor threemajor branches: the natural sciences, which stu ...
'', '' Contexts'', '' The Wilson Quarterly'', ''Technical Communication
Technical communication (or tech comm) is communication of technical subject matter such as engineering, science, or technology content. The largest part of it tends to be technical writing, though importantly it often requires aspects of visual ...
'', ''The University of Toronto Law Journal'', '' A Review of General Semantics'' and '' Scientific American Mind''.
The book was also reviewed in a monthly magazine ''Observer'', published by the Association for Psychological Science
The Association for Psychological Science (APS), previously the American Psychological Society, is an international non-profit organization whose mission is to promote, protect, and advance the interests of scientifically oriented psychology in r ...
.
The book has achieved a large following among baseball scouts and baseball executives. The ways of thinking described in the book are believed to help scouts, who have to make major judgements off little information and can easily fall into prescriptive yet inaccurate patterns of analysis.
The last chapter of Paul Bloom's Against Empathy discusses concepts also touched in Daniel Kahneman's book, Thinking, Fast and Slow, that suggest people make a series of rational and irrational decisions. He criticizes the argument that "regardless of reason's virtues, we just aren't any good at it." His point is that people are not as "stupid as scholars think they are." He explains that people are rational because they make thoughtful decisions in their everyday lives. For example, when someone has to make a big life decision they critically assess the outcomes, consequences, and alternative options.
Author Nicholas Taleb
Nassim Nicholas Taleb (; alternatively ''Nessim ''or'' Nissim''; born 12 September 1960) is a Lebanese-American essayist, mathematical statistician, former option trader, risk analyst, and aphorist. His work concerns problems of randomness, p ...
has equated the book's importance to that of Adam Smith's ''The Wealth of Nations
''An Inquiry into the Nature and Causes of the Wealth of Nations'', usually referred to by its shortened title ''The Wealth of Nations'', is a book by the Scottish people, Scottish economist and moral philosophy, moral philosopher Adam Smith; ...
'' and Sigmund Freud's '' The Interpretation of Dreams''.
Replication crisis
Part of the book has been swept up in the replication crisis
The replication crisis, also known as the reproducibility or replicability crisis, refers to the growing number of published scientific results that other researchers have been unable to reproduce or verify. Because the reproducibility of empir ...
facing psychology and the social sciences. It was discovered many prominent research findings were difficult or impossible for others to replicate, and thus the original findings were called into question. An analysis of the studies cited in chapter 4, "The Associative Machine", found that their replicability index (R-index) is 14, indicating essentially low to no reliability. Kahneman himself responded to the study in blog comments and acknowledged the chapter's shortcomings: "I placed too much faith in underpowered studies." Others have noted the irony in the fact that Kahneman made a mistake in judgment similar to the ones he studied.
A later analysis made a bolder claim that, despite Kahneman's previous contributions to the field of decision making, most of the book's ideas are based on 'scientific literature with shaky foundations'. A general lack of replication in the empirical studies cited in the book was given as a justification.
See also
* Behavioral economics
Behavioral economics is the study of the psychological (e.g. cognitive, behavioral, affective, social) factors involved in the decisions of individuals or institutions, and how these decisions deviate from those implied by traditional economi ...
* Cognitive reflection test
* Decision theory
Decision theory or the theory of rational choice is a branch of probability theory, probability, economics, and analytic philosophy that uses expected utility and probabilities, probability to model how individuals would behave Rationality, ratio ...
* Dual process theory
In psychology, a dual process theory provides an account of how thought can arise in two different ways, or as a result of two different processes. Often, the two processes consist of an implicit (automatic), unconscious process and an explicit ( ...
* List of cognitive biases
Cognitive biases are systematic patterns of deviation from norm and/or rationality in judgment. They are often studied in psychology, sociology and behavioral economics.
Although the reality of most of these biases is confirmed by reproducible ...
* Outline of thought
* Peak–end rule
* Joseph E. LeDoux
* Noise: A Flaw in Human Judgment
References
External links
How To Think Fast & Slow
excerpt at Penguin Books Australia
Daniel Kahneman changed the way we think about thinking. But what do other thinkers think of him?
– Various interviews about Kahneman and ''Thinking, Fast and Slow'' in an article in The Guardian.
{{Authority control
2011 non-fiction books
2011 in economic history
Books about bias
Books about cognition
Books about creativity
Choice modelling
Cognitive biases
Cognition
Decision-making
Farrar, Straus and Giroux books
Heuristics
Prospect theory
Psychology of learning
Risk analysis
Self
Thought
Thought experiments