Thinking, Fast and Slow

by Daniel Kahneman

  The results provided clear evidence of both duration neglect and a peak-end effect. In a between-subjects experiment (different participants saw different forms), doubling the duration of Jen’s life had Jto Aad Jto no effect whatsoever on the desirability of her life, or on judgments of the total happiness that Jen experienced. Clearly, her life was represented by a prototypical slice of time, not as a sequence of time slices. As a consequence, her “total happiness” was the happiness of a typical period in her lifetime, not the sum (or integral) of happiness over the duration of her life.

  As expected from this idea, Diener and his students also found a less-is-more effect, a strong indication that an average (prototype) has been substituted for a sum. Adding 5 “slightly happy” years to a very happy life caused a substantial drop in evaluations of the total happiness of that life.

  At my urging, they also collected data on the effect of the extra 5 years in a within-subject experiment; each participant made both judgments in immediate succession. In spite of my long experience with judgment errors, I did not believe that reasonable people could say that adding 5 slightly happy years to a life would make it substantially worse. I was wrong. The intuition that the disappointing extra 5 years made the whole life worse was overwhelming.

  The pattern of judgments seemed so absurd that Diener and his students initially thought that it represented the folly of the young people who participated in their experiments. However, the pattern did not change when the parents and older friends of students answered the same questions. In intuitive evaluation of entire lives as well as brief episodes, peaks and ends matter but duration does not.

  The pains of labor and the benefits of vacations always come up as objections to the idea of duration neglect: we all share the intuition that it is much worse for labor to last 24 than 6 hours, and that 6 days at a good resort is better than 3. Duration appears to matter in these situations, but this is only because the quality of the end changes with the length of the episode. The mother is more depleted and helpless after 24 hours than after 6, and the vacationer is more refreshed and rested after 6 days than after 3. What truly matters when we intuitively assess such episodes is the progressive deterioration or improvement of the ongoing experience, and how the person feels at the end.

  Amnesic Vacations

  Consider the choice of a vacation. Do you prefer to enjoy a relaxing week at the familiar beach to which you went last year? Or do you hope to enrich your store of memories? Distinct industries have developed to cater to these alternatives: resorts offer restorative relaxation; tourism is about helping people construct stories and collect memories. The frenetic picture taking of many tourists suggests that storing memories is often an important goal, which shapes both the plans for the vacation and the experience of it. The photographer does not view the scene as a moment to be savored but as a future memory to be designed. Pictures may be useful to the remembering self—though we rarely look at them for very long, or as often as we expected, or even at all—but picture taking is not necessarily the best way for the tourist’s experiencing self to enjoy a view.

  In many cases we evaluate touristic vacations by the story and the memories that we expect to store. The word memorable is often used to describe vacation highlights, explicitly revealing the goal of the experience. In other situations—love comes to mind—the declaration that the present moment will never be forgotten, though not always accurate, changes the character of the moment. A self-consciously memorable experience gains a weight and a significance Jto Ace Jto that it would not otherwise have.

  Ed Diener and his team provided evidence that it is the remembering self that chooses vacations. They asked students to maintain daily diaries and record a daily evaluation of their experiences during spring break. The students also provided a global rating of the vacation when it had ended. Finally, they indicated whether or not they intended to repeat or not to repeat the vacation they had just had. Statistical analysis established that the intentions for future vacations were entirely determined by the final evaluation—even when that score did not accurately represent the quality of the experience that was described in the diaries. As in the cold-hand experiment, right or wrong, people choose by memory when they decide whether or not to repeat an experience.

  A thought experiment about your next vacation will allow you to observe your attitude to your experiencing self.

  At the end of the vacation, all pictures and videos will be destroyed. Furthermore, you will swallow a potion that will wipe out all your memories of the vacation.

  How would this prospect affect your vacation plans? How much would you be willing to pay for it, relative to a normally memorable vacation?

  While I have not formally studied the reactions to this scenario, my impression from discussing it with people is that the elimination of memories greatly reduces the value of the experience. In some cases, people treat themselves as they would treat another amnesic, choosing to maximize overall pleasure by returning to a place where they have been happy in the past. However, some people say that they would not bother to go at all, revealing that they care only about their remembering self, and care less about their amnesic experiencing self than about an amnesic stranger. Many point out that they would not send either themselves or another amnesic to climb mountains or trek through the jungle—because these experiences are mostly painful in real time and gain value from the expectation that both the pain and the joy of reaching the goal will be memorable.

  For another thought experiment, imagine you face a painful operation during which you will remain conscious. You are told you will scream in pain and beg the surgeon to stop. However, you are promised an amnesia-inducing drug that will completely wipe out any memory of the episode. How do you feel about such a prospect? Here again, my informal observation is that most people are remarkably indifferent to the pains of their experiencing self. Some say they don’t care at all. Others share my feeling, which is that I feel pity for my suffering self but not more than I would feel for a stranger in pain. Odd as it may seem, I am my remembering self, and the experiencing self, who does my living, is like a stranger to me.

  Speaking of Life as a Story

  “He is desperately trying to protect the narrative of a life of integrity, which is endangered by the latest episode.”

  “The length to which he was willing to go for a one-night encounter is a sign of total duration neglect.”

  “You seem to be devoting your entire vacation to the construction of memories. Perhaps you should put away the camera and enjoy the moment, even if it is not very memorable?”

  “She is an Alzheimer’s patient. She no longer maintains a narrative of her life, but her experiencing self is still sensitive to beauty and gentleness.”

  Experienced Well-Being

  When I became interested in the study of well-being about fifteen years ago, I quickly found out that almost everything that was known about the subject drew on the answers of millions of people to minor variations of a survey question, which was generally accepted as a measure of happiness. The question is clearly addressed to your remembering self, which is invited to think about your life:

  All things considered, how satisfied are you with your life as a whole these days?

  Having come to the topic of well-being from the study of the mistaken memories of colonoscopies and painfully cold hands, I was naturally suspicious of global satisfaction with life as a valid measure of well-being. As the remembering self had not proved to be a good witness in my experiments, I focused on the well-being of the experiencing self. I proposed that it made sense to say 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 she wished to escape, and—very important because life is short—not too much time in a neutral state in which she would not care either way.

  There are many different experiences we would rather continue than
stop, including both mental and physical pleasures. One of the examples I had in mind for a situation that Helen would wish to continue is total absorption in a task, which Mihaly Csikszentmihalyi calls flow—a state that some artists experience in their creative moments and that many other people achieve when enthralled by a film, a book, or a crossword puzzle: interruptions are not welcome in any of these situations. I also had memories of a happy early childhood in which I always cried when my mother came to tear me away from my toys to take me to the park, and cried again when she took me away from the swings and the slide. The resistance to interruption was a sign I had been having a good time, both with my toys and with the swings.

  I proposed to measure Helen’s objective happiness precisely as we assessed the experience of the two colonoscopy patients, by evaluating a profile of the well-being she experienced over successive moments of her life. In this I was following Edgeworth’s hedonimeter method of a century earlier. In my initial enthusiasm for this approach, I was inclined to dismiss Helen’s remembering self as an error-prone witness to the actual well-being of her experiencing self. I suspected this position was too extreme, which it turned out to be, but it was a good start.

  n="4">Experienced Well-Being

  I assembled “a dream team” that included three other psychologists of different specialties and one economist, and we set out together to develop a measure of the well-being of the experiencing self. A continuous record of experience was unfortunately impossible—a person cannot live normally while constantly reporting her experiences. The closest alternative was experience sampling, a method that Csikszentmihalyi had invented. Technology has advanced since its first uses. Experience sampling is now implemented by programming an individual’s cell phone to beep or vibrate at random intervals during the day. The phone then presents a brief menu of questions about what the respondent was doing and who was with her when she was interrupted. The participant is also shown rating scales to report the intensity of various feelings: happiness, tension, anger, worry, engagement, physical pain, and others.

  Experience sampling is expensive and burdensome (although less disturbing than most people initially expect; answering the questions takes very little time). A more practical alternative was needed, so we developed a method that we called the Day Reconstruction Method (DRM). We hoped it would approximate the results of experience sampling and provide additional information about the way people spend their time. Participants (all women, in the early studies) were invited to a two-hour session. We first asked them to relive the previous day in detail, breaking it up into episodes like scenes in a film. Later, they answered menus of questions about each episode, based on the experience-sampling method. They selected activities in which they were engaged from a list and indicated the one to which they paid most attention. They also listed the individuals they had been with, and rated the intensity of several feelings on separate 0–6 scales (0 = the absence of the feeling; 6 = most intense feeling). Our method drew on evidence that people who are able to retrieve a past situation in detail are also able to relive the feelings that accompanied it, even experiencing their earlier physiological indications of emotion.

  We assumed that our participants would fairly accurately recover the feeling of a prototypical moment of the episode. Several comparisons with experience sampling confirmed the validity of the DRM. Because the participants also reported the times at which episodes began and ended, we were able to compute a duration-weighted measure of their feeling during the entire waking day. Longer episodes counted more than short episodes in our summary measure of daily affect. Our questionnaire also included measures of life satisfaction, which we interpreted as the satisfaction of the remembering self. We used the DRM to study the determinants of both emotional well-being and life satisfaction in several thousand women in the United States, France, and Denmark.

  The experience of a moment or an episode is not easily represented by a single happiness value. There are many variants of positive feelings, including love, joy, engagement, hope, amusement, and many others. Negative emotions also come in many varieties, including anger, shame, depression, and loneliness. Although positive and negative emotions exist at the same time, it is possible to classify most moments of life as ultimately positive or negative. We could identify unpleasant episodes by comparing the ratings of positive and negative adjectives. We called an episode unpleasant if a negative feeling was assigned a higher rating than all the positive feelings. We found that American women spent about 19% of the time in an unpleasant state, somewhat higher than French women (16%) or Danish women (14%).

  We called the percentage Jr">n Qge Jr">of time that an individual spends in an unpleasant state the U-index. For example, an individual who spent 4 hours of a 16-hour waking day in an unpleasant state would have a U-index of 25%. The appeal of the U-index is that it is based not on a rating scale but on an objective measurement of time. If the U-index for a population drops from 20% to 18%, you can infer that the total time that the population spent in emotional discomfort or pain has diminished by a tenth.

  A striking observation was the extent of inequality in the distribution of emotional pain. About half our participants reported going through an entire day without experiencing an unpleasant episode. On the other hand, a significant minority of the population experienced considerable emotional distress for much of the day. It appears that a small fraction of the population does most of the suffering—whether because of physical or mental illness, an unhappy temperament, or the misfortunes and personal tragedies in their life.

  A U-index can also be computed for activities. For example, we can measure the proportion of time that people spend in a negative emotional state while commuting, working, or interacting with their parents, spouses, or children. For 1,000 American women in a Midwestern city, the U-index was 29% for the morning commute, 27% for work, 24% for child care, 18% for housework, 12% for socializing, 12% for TV watching, and 5% for sex. The U-index was higher by about 6% on weekdays than it was on weekends, mostly because on weekends people spend less time in activities they dislike and do not suffer the tension and stress associated with work. The biggest surprise was the emotional experience of the time spent with one’s children, which for American women was slightly less enjoyable than doing housework. Here we found one of the few contrasts between French and American women: Frenchwomen spend less time with their children but enjoy it more, perhaps because they have more access to child care and spend less of the afternoon driving children to various activities.

  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. More important are situational factors such as an opportunity to socialize with coworkers, exposure to loud noise, time pressure (a significant source of negative affect), and the immediate presence of a boss (in our first study, the only thing that was worse than being alone). Attention is key. 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 than by the events of the moment. When happily in love, we may feel joy even when caught in traffic, and if grieving, we may remain depressed when watching a funny movie. In normal circumstances, however, we draw pleasure and pain from what is happening at the moment, if we attend to it. To get pleasure from eating, for example, you must notice that you are doing it. We found that French and American women spent about the same amount of time eating, but for Frenchwomen, eating was twice as likely to be focal as it was for American women. The Americans were far more prone to combine eating with other activities, and their pleasure from eating was correspondingly diluted.

  The
se observations have implications for both individuals and society. The use of time is one of the areas of life over which people have some control. Few individuals can will themselves to ha Jr">n Q ha Jr">ve a sunnier disposition, but some may be able to arrange their lives to spend less of their day commuting, and more time doing things they enjoy with people they like. The feelings associated with different activities suggest that another way to improve experience is to switch time from passive leisure, such as TV watching, to more active forms of leisure, including socializing and exercise. From the social perspective, improved transportation for the labor force, availability of child care for working women, and improved socializing opportunities for the elderly may be relatively efficient ways to reduce the U-index of society—even a reduction by 1% would be a significant achievement, amounting to millions of hours of avoided suffering. Combined national surveys of time use and of experienced well-being can inform social policy in multiple ways. The economist on our team, Alan Krueger, took the lead in an effort to introduce elements of this method into national statistics.