Anchoring and Adjustment: Self-Generated Anchors

Self-Generated Anchors

The results of these experiments reestablish the existence of anchoring and adjustment in some judgments under uncertainty. When questions activate self-generated anchors, people adjust from those anchors to arrive at final estimates. This process differs considerably from those involved when anchors are provided by an experimenter or other external source, demonstrating that there are distinct anchoring effects produced by different mechanisms. We therefore second Jacowitz and Kahneman’s (1995) call for a careful taxonomy of the varieties of anchoring effects in order to advance psychologists’ understanding of this pervasive element of judgment under uncertainty.

The present experiments have identified the anchor’s source as one important feature of that taxonomy – a feature that allows us to distinguish those anchoring effects that are produced by a process of adjustment and those that are not. It is noteworthy in this regard that the numeric estimates we investigate here share this feature with a number of phenomena that have been explained through a process of anchoring and adjustment – phenomena such as trait inference (Gilbert, Chapter 9, this volume), interpersonal communication (Keysar & Barr, Chapter 8, this volume), comparative ability estimates (Kruger, 1999), and various egocentric biases (Gilovich et al., 1998, 2000; Keysar & Bly, 1995; Van Boven, Dunning, & Loewenstein, 2000). Trait inferences begin with a dispositional attribution that observers generate themselves; similarly, communication, comparative ability estimates, and the processes involved in a host of egocentric judgments begin with a spontaneous consideration of one’s own comprehension, skills, or perspective on the world. Final judgments in these cases are thus likely the product of insufficient adjustment from these self-generated anchors. Note that many of these phenomena are amplified by cognitive load manipulations designed to hinder any underlying process of adjustment (Gilbert, Chapter 9, this volume; Kruger, 1999) – manipulations that have no effect on responses in the standard anchoring paradigm (Epley & Gilovich, 2001a).

Do adjustments from self-generated anchors tend to be insufficient? Research on trait inference suggests that although people try to adjust their impressions to accommodate situational influences, they adjust too little and are left inferring more about a person’s disposition than is logically warranted (Gilbert, Chapter 9, this volume). Research on comparative ability estimates paints a similar picture: Although people try to adjust for others’ ability level, they adjust too little and are left feeling systematically above average in domains in which absolute skill tends to be high, such as driving, and below average in domains in which it tends to be low, such as juggling (Kruger, 1999). Results from the control condition of Study 2 suggest that adjustments in numeric estimates also tend to be insufficient. Participants in that experiment estimated that George Washington, for example, was elected president in 1779 when he was actually elected in 1788. They also estimated that vodka froze at 1.75°F whereas the source’s reference answer was closer to −20°F. Indeed, we report elsewhere that people tend to systematically fall short of the actual answer when adjusting from self-generated anchors (Epley & Gilovich, 2001b).

This research provides the first compelling evidence that anchoring effects can be produced by a process of adjustment. Although the adjustment process is anything but fully understood, its existence now seems apparent.

* Originally published in Psychological Science, 12, 391–396. Copyright © 2001 by the American Psychological Society, reprinted by permission.