Thinking, Fast and Slow

by Daniel Kahneman

Indeed, we can be deeply moved even by events that change the stories of people who are already dead.

Most important, of course, we all care intensely for the narrative of our own life and very much want it to be a good story, with a decent hero.

The psychologist Ed Diener and his students wondered whether duration neglect and the peak-end rule would govern evaluations of entire lives.

An individual’s mood at any moment depends on her temperament and overall happiness, but emotional well-being also fluctuates considerably over the day and the week. The mood of the moment depends primarily on the current situation. Mood at work, for example, is largely unaffected by the factors that influence general job satisfaction, including benefits and status.

Our emotional state is largely determined by what we attend to, and we are normally focused on our current activity and immediate environment. There are exceptions, where the quality of subjective experience is dominated by recurrent thoughts rather

we draw pleasure and pain from what is happening at the moment, if we attend to it.

the decision to get married reflects, for many people, a massive error of affective forecasting. On their wedding day, the bride and the groom know that the rate of divorce is high and that the incidence of marital disappointment is even higher, but they do not believe that these statistics apply to them. The

Nothing in life is as important as you think it is when you are thinking about it.

enjoy greater well-being than others. The students in both regions shared the same mistaken view, and we were able to trace their error to an exaggerated belief in the importance of climate. We described the error as a focusing illusion.

The substitution caused you to ignore the fact that you rarely think about your car, a form of duration neglect. The upshot is a focusing illusion. If you like your car, you are likely to exaggerate the pleasure you derive from it, which will mislead you when you think of the virtues of your current vehicle as well as when you contemplate buying a new one.

However, the focusing illusion can also bring comfort. Whether or not the individual is actually happier after the move, he will report himself happier, because thoughts of the climate will make him believe that he is. The focusing illusion can cause people to be wrong about their present state of well-being as well as about the happiness of others, and about their own happiness in the future.

Daniel Gilbert and Timothy Wilson introduced the word miswanting to describe bad choices that arise from errors of affective forecasting. This word deserves to be in everyday language. The focusing illusion (which Gilbert and Wilson call focalism) is a rich source of miswanting. In particular, it makes us prone to exaggerate the effect of significant purchases or changed circumstances on our future well-being.

The remembering self, as I have described it, also tells stories and makes choices, and neither the stories nor the choices properly represent time. In storytelling mode, an episode is represented by a few critical moments, especially the beginning, the peak, and the end. Duration is neglected. We saw this focus on singular moments both in the cold-hand situation and in Violetta’s story.

The mistake that people make in the focusing illusion involves attention to selected moments and neglect of what happens at other times. The mind is good with stories, but it does not appear to be well designed for the processing of time. During

It does not make sense to evaluate an entire life by its last moments, or to give no weight to duration in deciding which life is more desirable.

The remembering self is a construction of System 2. However, the distinctive features of the way it evaluates episodes and lives are characteristics of our memory. Duration neglect and the peak-end rule originate in System 1 and do not necessarily correspond to the values of System 2. We believe that duration is important, but our memory tells us it is not. The rules that govern the evaluation of the past are poor guides for decision making, because time does matter.

The central fact of our existence is that time is the ultimate finite resource, but the rememberi...

The neglect of duration combined with the peak-end rule causes a bias that favors a short period of intense joy over a ...

The remembering self’s neglect of duration, its exaggerated emphasis on peaks and ends, and its susceptibility to hindsight combine to yield distorted reflections of our actual experience.

In contrast, the duration-weighted conception of well-being treats all moments of life alike, memorable or not. Some moments end up weighted more than others, either because they are memorable or because they are important.

The only test of rationality is not whether a person’s beliefs and preferences are reasonable, but whether they are internally consistent. A rational person can believe in ghosts so long as all her other beliefs are consistent with the existence of ghosts.

Rationality is logical coherence—reasonable or not. Econs are rational by this definition, but there is overwhelming evidence that Humans cannot be.

The definition of rationality as coherence is impossibly restrictive; it demands adherence to rules of logic that a finite mind is not able to implement. Reasonable people cannot be rational by that definition, but they should not be branded as irrational for that reason.

The way to block errors that originate in System 1 is simple in principle: recognize the signs that you are in a cognitive minefield, slow down, and ask for reinforcement from System 2.

people typically rely on the representativeness heuristic, in which probabilities are evaluated by the degree to which A is representative of B, that is, by the degree to which A resembles B. For example, when A is highly representative of B, the probability that A originates from B is judged to be high. On the other hand, if A is not similar to B, the probability that A originates from B is judged to be low. For an illustration of judgment by representativeness, consider an individual who has been described by a former neighbor as follows: “Steve is very shy and withdrawn, invariably helpful, but with little interest in people, or in the world of reality.