Thinking, Fast and Slow

by Daniel Kahneman

Norbert Schwarz and his colleagues invited subjects to the lab to complete a questionnaire on life satisfaction. Before they began that task, however, he asked them to photocopy a sheet of paper for him. Half the respondents found a dime on the copying machine, planted there by the experimenter. The minor lucky incident caused a marked improvement in subjects’ reported satisfaction with their life as a whole! A mood heuristic is one way to answer life-satisfaction questions. The dating survey and the coin-on-the-machine experiment demonstrated, as intended, that the responses to global well-being questions should be taken with a grain of salt. But of course your current mood is not the only thing that comes to mind when you are asked to evaluate your life. You are likely to be reminded of significant events in your recent past or near future; of recurrent concerns, such as the health of a spouse or the bad company that your teenager keeps; of important achievements and painful failures. A few ideas that are relevant to the question will occur to you; many others will not. Even when it is not influenced by completely irrelevant accidents such as the coin on the machine, the score that you quickly assign to your life is determined by a small sample of highly available ideas, not by a careful weighting of the domains of your life.