Book Review: “Thinking, Fast and Slow”

reviewed by Vivian Eng

Book CoverThinking, Fast and Slow by Nobel Laureate Daniel Kahneman is a popular psychology book on decision making that walks the fine line between pop science chock-full of theories, and empirical findings from psychology experiments. Usually circulating only among academics and a niche group of unusually curious folks with an appetite for journal articles, many results from these psychology experiments do not make their way to the masses. This is unfortunate since everyone from entry-level executives to CEOs in the corporate world, for example, make decisions every day that are prone to biases.

We observe, take in information and make judgments based on intuition that, in spite of ourselves, are easily misguided. This is where Thinking comes in to challenge anyone who picks up the book to take a step back and reexamine one’s own decision-making processes. Kahneman hopes that by bringing awareness to an audience that would otherwise be privy to the many cognitive biases we humans are slaves to, more people would be able to identify such biases and in doing so, make better decisions and judgements in everyday life. The book aims to stimulate intelligent discussions “by providing a richer and more precise language to discuss them”, as Kahneman puts it.

Indeed, Thinking is rife with terminologies from the more commonly known (at least among students of psychology) “confirmation bias”, “hindsight bias”, “halo effect” etc., to the less familiar “Florida effect”, “Lady Macbeth effect”, “conjunction fallacies”, and the “Moses illusion”. Compiling decades of research in the field into one easily understandable book is no small feat, yet Kahneman manages to accomplish just that, masterfully weaving in biases, fallacies, heuristics, illusions and the likes around two mechanisms of thought that purportedly form the basis for judgment making: “fast” and “slow” thinking.

“Fast” thinking, which Kahneman attributes to automatic thinking processes that occurs unconsciously and largely out of our control, is “designed to jump to conclusions from little evidence”. While “fast” thinking takes the lead in Thinking, “slow” thinking, an effortful and deliberate process, was relegated to a supporting role.

Kahneman illustrates the stark comparison between the two mechanisms by presenting a multiplication problem: 17 x 24. Intuitively, the automatic thinking component of our brain evaluates the mathematical problem and recognizes that there is a limited range of numbers that could be the possible solution. To obtain the precise solution, however, effortful thinking must come into play. Quick exercises like this peppered throughout the book, in order to engage readers to participate though sample vignettes and questions that help prove his points. 

It is thus a fun and entertaining read, as Kahneman has a flair for translating dense scientific literature into layperson terms through fluid and conversational writing. This is admittedly a refreshing change from reading textbook-style writing, at least in the beginning chapters. However, as I progressed through the book, it started to come across as mildly haphazard and even repetitious at times.

A sketchnote about the book. Photo: Eva-Lotta Lamm/Flickr(CC)

A sketchnote about the book. Photo: Eva-Lotta Lamm/Flickr(CC)

Nonetheless, I am a fan of writings with a personal touch. Mentioned extensively throughout the book is Kahneman’s close friend and colleague, the late Amos Tversky. I enjoyed reading about how their walks together sparked ideas, how conversations were turned into experiments, how disagreements between them propagated lines of research in theirs and other labs. Kahneman wrote of professional visits to financial firms, corporate dinners, family vacations, etc. anecdotes from everyday life which not only give context to how the experiments came about, but also served as a reprieve from the theory-laden text. Perhaps these brief personal accounts occupy less space in our working memory and allow us to “digest” and dwell on the theories without reducing our ability to think.

It should also be pointed out that in the relatively short time since the publication of the book, credibility of some of the research cited by Kahneman has been questioned. In particular, certain priming studies’ replicability had been challenged1 and Kahneman himself has addressed this issue2. Granted that the nature of rapidly evolving research is that it is open to criticism and constantly updated, readers should be prudent in making their own conclusions and perhaps take phenomena such as the “Florida effect” with a grain of salt.

If one is not bothered by the rambling-style writing, Thinking makes for an utterly enlightening read. Kahneman, with his background in behavioural economics coupled with an enthusiasm for story-telling, does a decent job in forcing us to seriously think about the way we think. As easy as it is to rely on intuitive thinking to make snap judgments, I am now much more informed of the cognitive biases that come with it, and would most definitely think twice and try to correct for such biases whenever possible.


[1] Doyen, S et al. (2012) Behavioral Priming: It’s All in the Mind, but Whose Mind? PLoS ONE 7: e29081.
[2] Yong, E. (2012) Nobel laureate challenges psychologists to clean up their act. Nature doi:10.1038/nature.2012.11535

About the Author

VIVIAN ENG is a brain-scientist-in-training who got her feet wet in brain and language research at the NeuroCognitive Imaging Lab. After graduating with a BSc (Hons) in Psychology from Dalhousie University (Canada), she is now a Research Assistant at Duke-NUS Graduate Medical School in Singapore while applying for graduate school. She enjoys travelling solo, reading, and catching up with old friends. Find out more about Vivian Eng by visiting her Scientific Malaysian profile at http:// and her personal page at