Thinking fast, thinking slow is a book published in 2011 by psychologist Daniel Kahneman (Tel Aviv, 1934). He is currently a professor of psychology at Princeton University.

A specialist in cognitive psychology, Kahneman’s main contribution to Economics consists in the development, together with Amos Tversky, of the so-called Prospect Theory, according to which individuals make decisions, in environments of uncertainty, that deviate from the basic principles of probability . They called this type of decisions heuristic shortcuts.

Kahneman won the Nobel Prize for… Economics!

In 2002, together with Vernon Smith, he was awarded the Nobel Prize in Economics for having integrated aspects of psychological research into economic science, especially with regard to human judgment and decision-making under uncertainty.

We recently included Daniel Kahneman in our ranking of the 12 most influential psychologists today. Being the only psychologist who has managed to win a Nobel Prize, his inclusion is more than deserved.

Think fast, think slow : a collection of his main ideas

In the book Thinking fast, thinking slow , Kahneman summarizes his research on the way human beings think . The author maintains the widely accepted thesis in current psychology about the two modes of thinking: the System 1 , fast, intuitive and emotional, and the System 2 , slower, more reflexive and rational.

The first one provides conclusions automatically, and the second one provides conscious answers. The peculiar thing is that, most of the time, we do not reflect on which of the two has taken the reins of our behavior.

A book divided into five thematic sections

The book is divided into five parts. The first part presents how the two systems work and how judgments and decision making by both take place. The second part delves into the heuristics of judgments and emphasizes the difficulties of System 1 in thinking statistically. The third part focuses on the inability to recognize uncertainty and our own ignorance and the overestimation of what we think we understand about the world around us.

The fourth part delves into the nature of economic decisions and poses the theory of perspectives under the hypothesis of the two systems. In the fifth part of the book Kahneman makes a distinction between what he calls "the self that experiences" (related to System 2) and "the self that remembers" (related to System 1). Sometimes the goal of happiness of both selves leads to clearly opposing situations.

Finally, and in a sort of conclusion, the implications of the three distinctions made in the book are examined: the self that recalls versus the self that experiences, decision making in classical economics versus decision making in behavioral economics, and System 1 versus System 2.

Several considerations and reflections on this book

We can consider Kahneman’s starting hypotheses to be highly original and attractive. In my opinion, he extends the concepts of System 1 and System 2 to the totality of thought processes. This vision models perfectly the making of decisions of the type " the first thing that has crossed my mind" in front of those decisions that we make after having reflected carefully. We can see an example of this in a simple problem that Kahneman himself poses:

A bat and a ball together cost $1.10

The bat costs $1 more than the ball

How much is the ball?

The immediate response is given by System 1:

The ball costs $0.10

Only a System 2 invocation will give us the right answer.

The System 1 and the System 2 , a simple way of conceptualizing thought

Physiologically speaking, we could even go so far as to postulate that the responses of System 1 emerge directly from the limbic system, naturally transformed and processed by the neocortical areas, while those of System 2 which involve more elaborate processing, (the intellectual-cognitive-reflexive) could only be carried out in the more modern cortical areas located in the prefrontal frontal cortical zone.

This consideration would situate System 2 as a structure exclusively proper to higher animals, which emerged evolutionarily as a complement to System 1.

Possible critiques of Kahneman’s work

Kahneman’s hypotheses could be considered excessively simplistic and somewhat anthropocentric , but after a little reflection, the analysis of behaviour from this point of view allows us to explain a large number of reactions observed in human behaviour in general and in particular, in the decision-making processes that must always be taken to a greater or lesser extent in environments of uncertainty.

The descriptions of the different hypotheses raised in the book are, in my opinion, excessively repetitive and not very synthetic (they could really be described in a few paragraphs) and the author tries to prove their validity with the somewhat disordered exposition of the results of a considerable number of experiments, which do not always seem to be the most appropriate and some of which do not provide very consistent arguments .

Unfortunately, Kahneman does not go into too much detail about the processes of gestation and birth of the different hypotheses he presents, processes that would probably facilitate their assimilation by readers.

Between the academic and the commercial…

The book seems to be conceived more as a popular book for the general public (along the lines of a best-seller or a self-help book) than as a scientific work. The examples, experiments and particular cases are profusely described, sometimes in a somewhat chaotic and disordered way and without a very defined thread, illustrating various aspects of the dualities presented.

Despite its informative nature, the book is not exempt from scientific rigor. All the statements made and each of the experiments are adequately referenced. All the bibliographical references, the author’s notes and also the conclusions are included at the end.

The most interesting thing: the study on the anchor effect

After reading it, one cannot help but feel both identified and surprised by some of the mental processes described in the book . Especially interesting are the aversion to loss and the anchor effect. In the first one, we are shown the natural tendency of people to avoid losing rather than gaining benefits. This leads to risk aversion when evaluating a possible gain, since it is then preferable to avoid a loss than to receive a benefit.

The so-called anchor effect (or 'anchor effect') tends to make us take as a reference the first offer (first data) that we have been given, mainly when we do not have complete and accurate information. It is also worth highlighting the effort made by Kahneman to quantify numerically the intensity of the anchor effect, a quantification that is not easy to carry out in most psychological processes.

A book recommended to professionals and curious people

In summary, we would recommend the reading of this book not only to professionals in the psychological sciences but in general to anyone interested in knowing themselves a little better , to deepen in the processes that determine their decisions and to equip themselves with mechanisms that allow them to advance one more step on the road to their happiness.