The Role of Optimism and Procrastination in the Planning Fallacy

Individual Differences Research

Ambrose Bierce, in the Devil’s Dictionary, defined the future as “that period of time in which our affairs prosper, our friends are true, and happiness is assured.” Samuel Johnson noted that marrying a second time represented the “triumph of hope over experience”. Both witticisms capture a certain quality of human nature: people – at least, some people – look at the future through rose-colored glasses. Daily life and psychological studies provide plenty of reasons to believe that optimism about the future is one important dimension along which people differ. Some people seem to awaken each day with the firm belief that every problem encountered hides an opportunity; other people awaken with the equally firm belief that every opportunity encountered hides a problem. Perhaps, then, the planning fallacy is not a general phenomenon, but limited only to the most optimistic and hopeful of our participants. We explored this possibility using a number of well-known individual difference measures to assess our participants’ levels of dispositional optimism (Scheier & Carver, 1985), self-esteem (Rosenberg, 1965), and non-clinical depression (Beck, Ward, Mendelson, Mock, & Erbaugh, 1961). In a number of student samples, we related such well-validated individual difference measures to recollections of past completion times, predictions for and thoughts about future tasks, and the actual completion times for those tasks (Buehler & Griffin, 2000a). We have been surprised by the lack of relation between any of these measures and our measures of recall, prediction, or thought focus.

In the same studies, we also measured participants’ level of dispositional procrastination, the tendency to delay starting projects (Ferrari, Johnson, & McGown, 1995; Lay, 1986). Procrastination is relevant to studies of the planning fallacy for two somewhat contradictory reasons: Procrastinators typically finish their projects later than non-procrastinators, and they are aware they have problems with time management. Thus, whether procrastination moderates the planning fallacy depends on the relative effect of procrastination on behavior and prediction. In the domains of academic predictions and Christmas shopping predictions, we discovered that behavior and prediction were equally affected by personal tendencies: Procrastinators (Lay, 1986) reported typical completion times that were later than non-procrastinators, made less optimistic predictions than non-procrastinators, and completed the tasks later than non-procrastinators. As a result, the optimistic bias was equal between groups. The costs were not equal, however; procrastinators suffered more because the average procrastinator completed the academic projects after the official deadline. Unique among the various groups we have studied, the procrastinators also showed a much reduced tendency to focus exclusively on the future when making predictions; almost 40% of their thoughts were on the past, presumably because of the salience and consistency of their past failures to initiate projects promptly. However, even self-admitted chronic procrastinators do not fully achieve the outside viewpoint. We succeeded in obtaining an outside viewpoint only by turning to real outsiders – observer participants. Recall that when we asked observers to predict actors’ outcomes, they evidenced a complete lack of future focus and no optimistic bias.