This book summarises the latest psychological research on human judgement, in particular how we think irrationally, jump to conclusions and fall prey to failures of intuition.
To give you a feel, here is an example from chapter 17. Have a look at this statement and see if you can guess why it might be true:
"Highly intelligent women tend to marry men who are less intelligent than they are"
Did you find a nice explanation? The book will show you why no explanation is necessary. It is a statistical necessity. It will also explain why it is very difficult to avoid believing spurious explanations and how pervasive and dangerous they can be.
That is just one tiny example. The book is absolutely packed with fascinating and thought provoking discussion of a wide range of similar topics. It is almost a must-read for anyone interested in human judgement or broader questions about how the mind works and one of very few books I keep on a special shelf for reading again.
There were a few things that niggled with me. I will mention these but please don't be put off. Even with the niggles it is an intelligent and valuable book.
The writing is clear and easy to understand. However it is a bit repetitive. After I got a feel for where the repetition was coming I often found myself skipping or skimming half a paragraph. Comparing this with Predictably Irrational by Dan Ariely, a book covering similar ground, Ariely's book gets its points across in a much punchier way and presents a similar amount of material in (I guess) half as many words.
The author gives other researchers credit where it is due but when talking about his own work I feel he overdoes his self-publicity. I have read plenty of books by acclaimed scientists and they don't boast about how good their work as much as Kahneman does. Some people may not mind this, or may not even notice it. Maybe I am being too sensitive but I did find it irritating so I think it is fair to mention it.
One final, very small, niggle. The book often uses names for psychological findings - the endowment effect, the halo effect, loss aversion, and many others. Usually these are widely accepted terms. However, Kahneman insists on coining a few of his own that are not accepted terms. The most notable, where he names different types of thinking "System 1" and "System 2", is central to the book and, although he gives a reasonable justification for it, it gave me a slight feeling of quackery which is a shame as this is an extremely intelligent book and not quackery at all. Someone has since pointed out to me that the terms System 1 and System 2 may become mainstream in which case I owe Kahnemann an apology and happily give it to him.
Because of the niggles, I started by giving the book 4 stars, but on reflection, it is so full of wise discussion and useful advice, I realized I was being churlish and gave it the extra star.
If you are interested in the subject I would strongly recommend reading both this and Predictably Irrational. Neither the style nor the material is the same. If you only want to read one book, or are new to the subject, you might prefer Predictably Irrational as it is more fun to read, and its ideas will grab you more quickly. I read Predictably Irrational in a couple of sittings but Fast and Slow Thinking took me 3 weeks as it is 400 pages of small print and I usually felt tired after reading 1-2 chapters. On the other hand, Thinking Fast and Slow will thoroughly reward the greater investment of effort. Another excellent book which predates this by 14 years is Hare Brain Tortoise Mind by Guy Claxton. This has a different take on the subject and, unfortunately, does not seem to be acknowledged anywhere.
on 9 February 2012
You are at the cinema watching the latest film. Fifteen minutes before the end, the projector explodes and the screening is terminated prematurely. You feel that the experience was ruined. However, Daniel Kahneman knows better - he asserts that you are mistaken! Your own mind has deceived you. A combination of `duration neglect' and the `peak end rule' is responsible. You have difficulties distinguishing your memories from your experiences. He claims you found the experience blissful (despite having missed the end), no matter what you believe.
This is an example of one of the rather silly assertions which can be found towards the end of this 418 page book. There are quite a few equally foolish theories throughout the last 200 pages.
This is a book of two halves. The first half is absolutely inspirational. The writing style here is excellent. In order to illustrate his points, the author provides many exercises for the reader to perform. In doing these you conduct little experiments on your own brain, which will astonish you time and again by the obvious errors and self deceptions it keeps making. By page 200 I was feeling this was one of the very best books I have ever read. The material shows beyond doubt that the mind of the human is full of flaws, biases and delusions.
And then comes the second half. The writing becomes more turgid, the little exercises stop coming, and the lessons become more and more flaky, culminating in the example I give at the beginning. What went wrong?
Mr Kahneman points out that the human brain is biased towards finding coherence where there is none, and that we are susceptible to a frightening level of overconfidence. No where is this better illustrated than in the second half of his own book. Having found many instances of irrational thinking, particularly where statistics are concerned, Mr Kahneman seems to become obsessed with irrationality, and seeks to find the same pattern in all aspects of human behaviour. He becomes more and more overconfident with the tidy and coherent story he has constructed, and produces some spectacularly silly theories as a result.
I would give the second half of the book barely one star. But read it for the first 200 pages, which fully deserve five stars!
Daniel Kahneman has produced an excellent book. He continues to build and expand on the famous paper he and Amos Tversky published in 1974 ("Judging Under Uncertainty", a copy of which is usefully appended to this book) and has since spawned innumerable books on the theme (eg Wray Herbert's "On Second Thought"), and even related themes like Nassim Taleb's "Black Swan". "Thinking Fast and Slow" is not a textbook; it is intended for the layman who wants to have a clear and deep understanding of man's cognitive functions. Most of Kahneman's studies will amaze readers not familiar with this subject. For example, when tested, it is still remarkable that the clinical judgments of trained professionals are less accurate than statistical predictions based on a few scores or ratings. Hence counsellors who interviewed students were less accurate in their predictions on the students' performance than statistical predictions using only a few denominators such as High School grades and aptitude test results. The reason Kahneman, a psychologist, was awarded the Nobel Prize in economics was that his (and Tversky's) thesis was applied by economists to understand why economic and financial predictions so often go wildly wrong when they were (or so it was believed) so carefully and rationally made.
This review also hopes to point readers to a book I read as a student in 1967. It's called "Straight and Crooked Thinking" by R H Thouless. That book has so many similar points and Thouless was a teaching psychologist from Cambridge University in the UK. Although Thouless' book concerns flaws in the use of language and logic in thinking, it also discusses the effect of hidden bias and prejudice. Straight and Crooked Thinking has just been published in the 5th edition by R H Thouless' grandson, C R Thouless. The first was published in 1930. Kahneman's book will likely be as long lived.
on 25 August 2014
Daniel Kahneman is a behavioural economist. He’s spent decades studying the effects of social, cognitive and emotional factors on the decisions we make – economic and otherwise. In Thinking, Fast and Slow, he shares some of the insights of his work in decision science: to stimulate, as he says, “watercooler conversations”, so that we can better understand the systemic errors of judgement that humans are prone to.
Kahneman explains his findings by invoking the fiction of two ‘systems’. System 1 is intuitive, associative and fast; System 2 is rational, logical, slow and lazy. System 1 prefers plausibility to probability; it craves coherent meaning and will do everything it takes to construct it from any scrap of information. It cannot deal with statistics; it prefers causal explanations every time. It hates doubt. System 2 does its best to understand the truth in all its fullness; but it can only work with what System 1 gives it, and it’s lazy: without conscious attention and effort, System 2 will simply ratify the decisions of System 1.
As so often with discussions based on experimental social science, I found myself mildly irritated that experiments seemed merely to confirm what most of us know by experience already. But that, of course, is precisely Kahneman’s point: experience is not an infallible guide to truth. The illusion that we understand the past fosters overconfidence in our ability to predict the future.
“Everything,” he says, “makes sense in hindsight.”
The penny, for me, dropped with a resounding crash in Chapter 20. At one point, Kahneman and his colleague, Amos Tversky, worked with a group of investment advisers, looking for evidence of skill in their ability to predict movements in stock prices.
They found none. The results of every single adviser, over time, were no better than blind betting.
The conclusion, for me, is inescapable: the livelihoods and self-esteem of thousands of financial professionals depend entirely on their rhetorical skills.
Kahneman delivers over 400 pages of material showing how incapable we are of understanding statistics, how brilliant we are at ignoring our ignorance, how we regularly substitute easy questions for hard ones in decision-making, and other cognitive biases. This book is fast becoming a central reference in the growing conversation about rationalism and intuition. (Check out Ted Cadsby's "Closing the Mind Gap", Guy Claxton's "The Waywrd Mind", and my own "How to Solve Almost Any Problem".)
Getting through the book can be hard work, not least because Kahneman's pessimism can get wearing. My biggest concern is that he seems to ignore one aspect of System 1 that has been highly successful in driving human progress.
Look in the index, and you will find no entry for 'imagination'.
A longer version of this review appears at:
on 25 January 2012
I dont normally write reviews but felt I should with this book.
Im probably your average reader - an interest in psychology and to some degree, self help/improvement publications.
I have done a fair bit of academic reading, so understand the difference between an academic style of writing and a book for 'the masses'. This is where I think the book falls down. Some chapters of the book really are extremely well worded and presented to the reader - concepts are clear and not unnecessarily complicated. Other chapters lapse into a pseudo-academic style which I found tedious and tiresome. I don't really need all the statistical data and complicated information behind the proposals Kahneman makes - I want him to package it up into a readable format which dose not require me to read it three times to 'get' what he means. It really is as though someone else wrote parts of the book, as its style does seem to change significantly in places.
So, some sections are quite brilliant and inspirational, worthy of 6 starts from me....but other chapters mar the reading experience, making it quite a chore. A mixed bag........
This is a marvellous book. I'd hesitate to go quite so far as Nassim Taleb, author of The Black Swan and Fooled by Randomness, who is quoted on the dust cover as saying, 'In the same league as The Wealth of Nations by Adam Smith and The Interpretation of Dreams by Sigmund Freud'. Well, maybe not quite in that league, but only because this work is the continuation of many strands of thought in psychology rather than an epoch-changing , intellectual bombshell. The ideas in this book are already, however, changing the ways in which all of us think about the way that we think (if that makes sense) and many of those strands of thought (sorry) were in any case started by Kahneman himself with his earlier collaborator, Amos Tversky, who died in 1996. Kahneman writes, selflessly and touchingly, about his fourteen years working with Tversky: `Our collaboration was the focus of our lives, and the work we did together during those years was the best either of us ever did.' Maybe Taleb is right, and in fifty years' time Kahneman and Tversky will be even more famous than they are now, and people will be asking, `Sigmund Who?' It could happen.
There are two kinds of thinking, says Kahneman, slow thinking (like doing hard mental arithmetic) and fast thinking, which happens so quickly that we don't even notice. Slow thinking takes a lot of brain energy. Our pupils dilate, revealing the increased energy that is required for such difficult mental tasks. Because our available mental energy is limited, when we are working on such `slow-thinking' mental tasks, we will be unable to take on other mental tasks and may fail even to perceive apparently obvious things: there is a strict limit to how much attention our brain can deliver at any one time.
As a result, we make most of our decisions the easy way, as in, `This seemed to work before, let's try this route again'- what psychologists call `heuristics' and what we tend to call `rules of thumb'. Our brains, not surprisingly, follow the `law of least effort'. If there is a quick route to a solution, we will take it. We hardly even notice that we have taken the quick route: our brains have the capacity to challenge any such `quick' solution but, in general - guess what? - we let it go. The problem, says Kahneman, is that our `quick thinking' is subject to a disturbingly large number of `systematic biases and errors.' Kahneman goes on to investigate an alarming number of these systematic errors and biases, of which only one is the `anchoring' effect: our decisions are affected, for example, by a number of which we have recently been made aware. `If you are asked whether Ghandi was more than 114 year old when he died you will end up with a much higher estimate of his age at death than you would if the anchoring question referred to death at 35.' In the same way, your idea of how much you should pay for a house is influenced by the asking price - even if you want to believe that it wasn't.
Our decisions can also be 'primed' by what has recently come to our attention. This leads to some relatively obvious effects - we are more likely to vote for legislation in favour of school funding if the polling station is in a school; and some far stranger effects - students exposed to a number of words related to old age walk more slowly after the exposure than groups exposed to other words. They do not report that they were aware that the words had a common theme (old age) and they are not concious of the change to their behaviour (walking more slowly).
'Substitution' causes us to answer an easier question ('How do I feel about this') rather than a harder question (What do I think about this?). 'Availability' causes us to overestimate the effect of more dramatic events, because they are more 'front of mind'. The list goes on . . .
The book offers a wealth of other compelling examples of the ways in which our `fast thinking' is prone to error, all clearly suggested by the results from a number of elegant experiments. If you don't agree with Kahneman's conclusions, devise your own experiments and test the results: this is science, not metaphysics.
Thinking Fast and Slow may (perhaps) be less famous than The Wealth of Nations or The Interpretation of Dreams in fifty years' time, but it's a lot more readable than the former and a lot more scientific than the latter. And it will change your life - or at least how you feel about the reliability and robustness of our decision-making.
on 10 November 2011
And neither, for me, is dislike of this wonderful book an option. By the time Daniel Kahneman reassures the reader that the results of the various priming studies he has just been discussing are neither made up nor statistical flukes - and that "disbelief is not an option" - I was more than ready to take this as an avuncular and not an inquisitorial admonition. There is a warmth in the writing, and not only from scholarly passion for the subject. As well as being a masterly exploration of a fascinating part of human nature, this book is a tribute to a remarkable collaboration with Amos Tversky, and dedicated to his memory. That his name does not appear in the formal acknowledgements at the end of the book is no oversight: his spirit infuses the text, surfacing every so often in the plural subject "Amos and I" as Kahneman describes with relish some piece of scientific research they conducted together.
In a book that exposes errors we often don't realize we're making, it is fitting that the author himself fesses up. Kahneman admits that early in his career, like many psychologists, he was often guilty of choosing samples that were too small, getting results that made no sense and which - it eventually dawned on him - were actually artifacts of his research method: "My mistake was particularly embarrassing because I taught statistics and knew how to compute the sample size that would reduce the risk of failure". He learned to be wary of intuition and tradition, and, unlike most psychologists, went on to collect a Nobel prize, for work done with Tversky on judgment under uncertainty and prospect theory (published in two widely cited papers that are reproduced as appendixes).
Truly random errors can't be predicted, of course. The human mind, however, is somewhat more accommodating to scientific study in that it distorts reality in systematic ways, and these errors - or biases - "recur predictably in particular circumstances". A recurrent theme of the book centres on one particularly strong bias, towards causal explanations and away from statistical analysis. People "are prone to apply causal thinking inappropriately, to situations that require statistical reasoning". One clue to this tendency is that while even children are good intuitive grammarians, pretty much all adults (including professional statisticians) are poor intuitive statisticians. We prefer stories to sets of data, agency over chance, and we care more about coherence than either the quantity or quality of the data on which the story is based.
For someone who warns us to beware of stories, Kahneman's is a compelling narrative, at the heart of which are two characters who in turn entertain and exasperate, who sometimes work well together and who are sometimes in conflict, but without whom we would not be human. They go by the prosaic labels System 1 and System 2 and are vital for understanding how we make judgements and decisions.
In brief, the automatic System 1 and the effortful System 2 "respectively produce fast and slow thinking". System 1 is brilliant at identifying causal connections between events, while System 2, your conscious self, is the part of the mind that can concentrate on thinking a problem through. System 1 is always on, generating "intuitive feelings and opinions about almost everything that comes your way", and while it is never stumped it is "gullible and biased to believe". Given these aspects of System 1's character, the "laziness of System 2 is an important fact of life": System 2 ("in charge of doubting and unbelieving") could step in to stop you jumping to an unwarranted conclusion. It often fails to intervene, however, because it's often terribly busy and finds it hard to multitask. Besides, following "our intuitions is more natural, and somehow more pleasant, than acting against them". As for attitudes, "System 2 is more of an apologist for the emotions of System 1 than a critic of those emotions - an endorser rather than an enforcer".
"The measure of success for System 1 is the coherence of the story it manages to create. The amount and quality of the data on which the story is based are largely irrelevant. When information is scarce, which is a common occurrence, System 1 operates as a machine for jumping to conclusions."
My guess is that regression to the mean has not set many pulses racing (examinations apart), and yet it provided Kahneman with "one of the most satisfying eureka experiences" of his career, when he "stumbled onto a significant fact of the human condition: the feedback to which life exposes us is perverse. Because we tend to be nice to other people when they please us and nasty when they do not, we are statistically punished for being nice and rewarded for being nasty." Performance varies, and the chance element will both regress to the mean and be ignored: a golfer who has a good first day in a competition is likely to do less well on the second (despite all the praise), and a golfer who has a bad first day is likely to improve (despite all the flak). Most spectators and commentators ignore statistics and rely on intuition to predict the scores on the second day, and as a result will "tend to be overconfident and overly extreme". It goes without saying that golf tournaments are not the only situations when intuitive predictions "need to be corrected because they are not regressive and therefore are biased".
This book will be of interest to anyone who has woken up this morning, and is therefore experiencing, first hand, the push and pull of fast and slow thinking. Psychologists, however, should be warned about a potentially demoralizing conclusion: despite Kahneman's evident enthusiasm for his subject, it seems "that teaching psychology is mostly a waste of time". Reading this book most certainly isn't, although I do have a couple of further health warnings regarding this review: (a) I haven't quite finished reading the whole book and (b) I've just begun a chapter entitled "The Illusion of Understanding"...
If you're a fan of psychology books, you've probably heard of Daniel Kahneman. The guy has a Nobel Prize in economics, making him one of the most famous living psychologists around. He knows what he's talking about and fills this book with a huge amount of information about how the mind works.
The central thesis of the book is that we humans are almost two separate entities. One side of us is instinctive, impulsive and relies on making fast judgements and quick impressions. The other side of us is more deliberate and allows us to (sometimes) overrule this more gutsy side of us. Throughout the book, Kahneman provides study after study after study to illustrate these two side of the mind.
Unfortunately, I found the book more long-winded and meandering than I would have liked. Kahneman provides lots and lots of examples, but sometimes goes into too much detail or swamps us with too much information. Occasionally, for example, the book comes across slightly more as a memoir that would be interesting for him to have written rather than a book that is aimed at educating and entertaining a wide readership.
In addition, Kahneman may be a highly decorated scientist, but he's not a natural writer. He assembles sentences with clauses and sub-clauses that sometimes hamper their comprehension. That doesn't mean that I didn't understand the book, but I did sometimes have to read sentences several times to get precisely the point that he was making.
For content, this book cannot be beaten. There's a huge amount in this hefty book. But the fact that it is so comprehensive made it (for me) a less enjoyable read. In trying to squeeze absolutely everything about the brain and mind into one book, I felt that there was too much to take in. Taking some of the content OUT to make the book more focused would have made it a more enjoyable read in my personal opinion.
Other psychologists have covered similar ground in an easier-to-read fashion, including Richard Wiseman 59 Seconds: Think a little, change a lot, Rob Yeung I is for Influence: The new science of persuasion: Mastering the Art of Influence, Daniel Pink Drive: The Surprising Truth About What Motivates Us and Daniel Nettle Personality: What makes you the way you are.
Other reviews here more than cover the content of this book but I want to review it anyway, mainly to offer a cautionary tale about not judging a book on the basis of disliking... other books. Because I was initially highly wary about this book, mistaking it for one of these pop science/social psychology-types which have become so successful in the last decade. I'm talking about books like Nudge or the Freakonomics series or those by Malcolm Gladwell (e.g. Blink), Nassim Nicholas Taleb (e.g. The Black Swan), Tim Harford (as the Undercover Economist) etc... all very loosely akin insofar as, despite having substantive statistical contents, they apply their own (seemingly dry discipline) to everyday situations and offer quirky `behaviouralist' ways of understanding the world. They seem to have arrived at a shared formula for making maths palatable to the general reader. Indeed their readability has led to their adoption by corporate culture and a rather odd state of affairs whereby `economics' books have become airport reading. Not a problem itself but in order to make the technical accessible, many of these authors have traded off scientific rigour in favour of readability. In sacrificing the maths, a certain degree of imprecision has been accepted as OK (see for example the lamentable (non)coverage of regression analysis in Freakonomics). Whereas I don't think it's OK. So I pretty much wrote-off `Thinking, Fast and Slow' when I saw the endorsements by Levitt (Freakonomics), Thaler (Nudge) et al on the cover. But I was wrong to do so. First, Kahneman knows his apples. Unlike Gladwell, he's won the Nobel Prize (in economics, despite being a psychologist). Second, much like Leonard Mlodinow (see `The Drunkard's Walk' for a stats equiv.), Kahmenn is a translator of behavioural economics into English but he doesn't jettison scientific rigour in so doing. He trusts the reader's intellect sufficiently to actually show you the correlation coefficients AND spin a good yarn. The chapters here all are short, beautifully clearly written, and none requires any special learning... but some are borderline taxing. But rather than detracting from the experience, my thinking is that this makes for greater intellectual satisfaction for the reader.
Daniel Kahneman will be familiar to practically all readers interested in detrimental effects or tricks our brain plays when we make decisions, and to people interested in psychology or behavioural economics more generally. Together with Amos Tversky, it is fair to say that he was one of the founders of the field and the earlier books, such as Judgment under Uncertainty: Heuristics and Biases and Choices, Values, and Frames are rightfully regarded as being classics in decision research.
With his latest book he summarizes most of the research effort in the area over the past 40 years, drawing heavily on own work but by no means excluding significant contributions from other notable researchers. In a way one could call this the 'if you only read one book on decision making, make sure it is this one' summary.
For the businessperson or a layman generally interested in the topic, it will provide the whole spectrum of effects to be aware of, when making assessments on how one's (or somebody elses) conclusions could be biased, and the processes (evolutionary and otherwise) behind such a functioning / conditioning of our brains. Having been a leading figure in the field for four decades, Kahneman has had a lot of his concepts reach the buzzword stage by now and it is certainly worthwhile to let the author himself explain again the 'science' and logic behind them.
It is a great book to give to junior researchers or analysts as a starting point, sort of a guide to the mistakes they will inevitably make and how to minimize their effects. In that sense it perfectly complements Hubbard's How to Measure Anything: Finding the Value of Intangibles in Business as induction material in both of the fields mentioned above (Paulos' Innumeracy: Mathematical Illiteracy and Its Consequences being another solid primer).
But even for an experienced researcher, or someone who has read a large portion of what went on before in the field, including the main body of the author's work, the book will be a gem. First of all, the book pulls everything together (including a reprint of the original 'Judgement under Uncertainty: Heuristics and Biases' article from Science Magazine) and provides you with a much quicker way of getting to know about all the recent developments on the topic than a thorough literature research would do (of course it is not a replacement for it, if you are writing an academic publication). Secondly, and perhaps more importantly, the author is a wonderful story teller and the writing will truly draw you in - the book is a real pleasure to read.
On top, his vast breadth of research distinguishes the book from some other recent, more 'pop type' efforts on behavioral economics in the way that there is not a whole book to fit into a specific, strongly delineated 'theory' or framework (a sort of 'interpretation of the day' and probably the only quick and dirty way someone without the patience and stamina needed to produce a work of this calibre has in order to make it big quickly), which would make it appear forced at times.
I cannot recommend the book warmly enough and even if you have little time in your busy schedule and the book comes in at over 400 pages, it really is worth your while (as well as pleasurable) reading it from cover to cover.