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Research Dialogue
Anchoring unbound
Nicholas Epley
a,
⁎, Thomas Gilovich
b
a
University of Chicago, Chicago, IL, USA
b
Cornell University, Ithaca, NY, USA
Received 7 December 2009; accepted 7 December 2009
Available online 8 January 2010
Abstract
An attitudes and persuasion perspective can broaden our understanding of anchoring by highlighting sources of variability in anchoring effects
that have been largely overlooked. As the target article suggests, research guided by this perspective can help identify (1) different types of
anchors that exert their influence through different underlying mechanisms, 2) important social psychological moderators of anchoring effects, and
3) sources of variability in the consequences of anchoring for judgment and choice. In this commentary, we take an even broader perspective on
the types of anchors that are likely to influence judgment, suggesting four potentially distinct types—intuitive approximations, best/worst case
scenarios, environmental suggestions, and magnitude priming. We conclude by discussing how an attitudes and persuasion perspective on
anchoring may provide novel insights into the moderators and consequences of anchoring effects in everyday life.
© 2009 Society for Consumer Psychology. Published by Elsevier Inc. All rights reserved.
We applaud Wegener, Petty, Blankenship, and Detweiler-
Bedell's effort to broaden the study of anchoring by approaching
the subject from an attitude and persuasion perspective. The
main benefit of this broader perspective is that it brings into view
sources of variability in anchoring effects that have so far been
largely ignored: variability in the kinds of anchors that influence
judgment, variability in processes that give rise to anchoring
effects, variability in the contexts in which anchoring effects are
likely to be elicited, and variability in the consequences of
anchoring that go beyond an immediate influence on numerical
judgment.
This broader perspective on anchoring marks a third wave of
research on anchoring, one that we think is very promising. The
first wave, starting with Tversky and Kahneman's (1974)
inclusion of anchoring as one of three basic heuristics in
intuitive judgment, sought to establish whether anchoring was
unambiguously a bias in judgment. Ever more extreme steps
were taken to insure that the anchor values could not be taken as
useful hints to the correct answer. We consider this wave now
over. No normative model would maintain that such transpar-
ently random numbers as the outcome of a spinning wheel
(Tversky & Kahneman, 1974), one's telephone number (Russo
& Shoemaker, 1989), or the last two numbers in one's social
security number (Ariely, Loewenstein, & Prelec, 2003) should
influence judgment.
The second wave of research was a constructive attempt to
identify the psychological mechanism responsible for anchor-
ing. This wave is still moving, as not just one but several
mechanisms appear to produce anchoring effects in different
contexts. These include confirmatory hypothesis testing
(Chapman & Johnson, 1994; Strack & Mussweiler, 1997),
numeric or magnitude priming (Wong & Kwong, 2000;
Oppenheimer, Leboeuf, & Brewer, 2008), and insufficient
adjustment (Tversky & Kahneman, 1974; Epley & Gilovich,
2001). An attitudes and persuasion perspective does not seem to
add to this second wave of research because it does not identify
what the underlying mechanisms might be in different contexts,
but it does make predictions about the consequences of more
and less elaborate processing. Different effects of high and low
elaboration might signify different underlying mechanisms, as
Wegener et al. suggest, but such differences could also reflect
the effects of more or less elaboration on the very same
underlying mechanism. It is not clear in the experiments
described by Wegener et al., for instance, whether participants
under high versus low cognitive load are simply engaging in
less of the same selective accessibility process or if they are
engaging in a fundamentally different process.
A
vailable online at www.sciencedirect.com
Journal of Consumer Psychology 20 (2010) 20 –24
Journal of
CONSUMER
PSYCHOLOGY
⁎Corresponding author.
E-mail address: epley@chicagobooth.edu (N. Epley).
1057-7408/$ - see front matter © 2009 Society for Consumer Psychology. Published by Elsevier Inc. All rights reserved.
doi:10.1016/j.jcps.2009.12.005
The third wave of anchoring appears to be building, one that
adopts a broader perspective on the phenomenon (or phenom-
ena) and unbinds anchoring from the dominant experimental
paradigm that has been used to study it. This third wave
considers anchoring in all of its everyday variety and examines
its various moderators in these diverse contexts. This is where
we believe an attitudes and persuasion perspective is likely to
have the most constructive impact, as this perspective naturally
focuses on the social context in which anchors arise and makes
predictions not only about the extremity of a given judgment,
but about its durability as well. Wegener et al.'s target article
left us with little to criticize about their general approach. We
think it is both promising and overdue. Instead, it left us
interested in trying to expand their contribution by suggesting
three ways in which anchoring research might broaden further
in the coming years: (1) by analyzing more systematically the
different types of anchors that occur in everyday life, (2) by
identifying important contextual moderators of anchoring
effects, especially social moderators, and (3) by considering a
wider variety of consequences of anchoring beyond an
immediate influence on the extremity of a given judgment.
We consider the first of these in some detail in this commentary,
and then describe the last two in closing.
Varieties of anchors
Tversky and Kahneman (1974) argued that anchoring effects
could explain a variety of existing biases in judgment, such as
the tendency to overestimate conjunctive events and underes-
timate disjunctive events (Bar-Hillel, 1973), and the tendency to
draw overly narrow confidence intervals around predictions
(now referred to as overprecision, Moore & Healy, 2008). More
important, they also identified two novel demonstrations of
anchoring, one that has dominated research on the subject for
more than 30 years and one that few people appeared to notice.
The former is the two-step procedure, targeted exclusively by
Wegener et al., in which people are first asked whether the
correct answer to a question is more or less than an anchor value
(e.g., is the height of Mt. Everest more or less than 50,000 ft?)
and are then asked to provide the actual estimate (e.g., what is
the actual height of Mt. Everest). The relatively unnoticed
demonstration was to have participants estimate the solution to
8!, presented either in ascending (1 ×2×3×4×5×6×7×8) or
descending order (8 ×7×6×5×4×3×2×1). Estimates in the
ascending condition were considerably smaller than estimates in
the descending version, presumably because people's first few
calculations served as an anchor.
Notice that the anchor values in these two paradigms bear
little relation to each other. The anchor value in the standard
paradigm is provided by an external source in the context of an
explicit comparison, whereas the anchor value in the 8! task is
generated by participants themselves as an initial starting point
that is in need of some final adjustment. The standard anchoring
paradigm is therefore analogous to persuasion contexts in which
a strong argument is presented for people's explicit consider-
ation in the attempt to elicit agreement and alter people's
attitudes. The 8! problem is not at all like a persuasion context,
but we believe it is like many judgments in everyday life in
which people do not know the answer to a given question but
know something close that can be used as a starting point. People
may not know the likely selling price of their own house but may
know the selling price of the nicer house next door. People do not
know the closing value of tomorrow's stock market, but do know
today's closing value. And people may not know when they are
likely to complete an important project, but know when they
plan to complete it.
Anchor values in everyday life come in different varieties,
and these varieties matter because they may be guided by
different underlying mechanisms, some of which are likely to be
high-elaboration processes (such as elaborated versions of
selective accessibility) and others relatively low-elaboration
processes (such as numeric priming). We think it would be
productive to apply the attitudes and persuasion perspective to
these different forms of anchoring as well. To help this effort
along, we delineate some of the very different types of anchors
to which this perspective might be applied.
Intuitive approximations
Anchoring was originally proposed by Tversky and Kahenman
as a heuristic used in judgment—an intuitive strategy that
substitutes a rather simple calculation in place of a more laborious,
complicated, or perhaps even impossible one. Anchoring is likely
to operate as such a heuristic in domains in which people can
quickly generate a response that they know is close to the correct
answer, but off the mark and in need of adjustment or correction to
arrive at the correct value. These intuitive approximations are
generated by participants themselves rather than provided by an
external source. More important, these values are known to be
wrong from the beginning and are therefore unlikely to activate the
selective accessibility process that appears to guide anchoring
effects in the standard anchoring paradigm. Except for dedicated
readers of the anchoring literature, few Americans are likely to
know when George Washington was elected President of the
United States, but most know that the U.S. declared its
independence in 1776 and that Washington must have been
elected not long after that. These “self-generated anchors,”as we
have called them to contrast them with the externally-provided
anchors in the standard anchoring paradigm (Epley & Gilovich,
2001), appear to produce anchoring effects through a process of
(insufficient) adjustment as people move from the intuitive
approximation to consider values ever further from the initial
anchor until they find a plausible response, at which point they
stop adjusting (Epley & Gilovich, 2004; Quattrone, Lawrence,
Finkel, & Andrus, 1981). Because adjustment stops once people
reach the realm of values they find plausible, their final estimate is
likely to be biased in the direction of the initial anchor value (Epley
& Gilovich, 2006). This would be considered a high elaboration
process, and sure enough, anchoring effects involving these self-
generated anchors are diminished when people lack the
motivation or mental capacity to engage in such mental effort
(Epley & Gilovich, 2005).
Similar intuitive approximations or self-generated anchors
have been proposed as components of a variety of social
21N. Epley, T. Gilovich / Journal of Consumer Psychology 20 (2010) 20–24
psychological assessments, including perspective taking
(Epley, Keysar, Van Boven, & Gilovich, 2004), dispositional
inference (Gilbert, 1989), and affective forecasting (Gilbert,
Gill, & Wilson, 2002), among others (Epley, 2004). An
attitudes and persuasion perspective on these kinds of anchors
would predict larger anchoring effects in domains in which
people feel they have some expertise, and therefore find
themselves to be highly credible sources, but weaker in domains
in which people feel they are relatively ignorant. Estimates
derived from these sorts of intuitive approximations should also
be relatively durable because of the high elaboration involved in
the adjustment process.
Best- and worst-case scenarios
We were unsure how long it would take to write this
commentary, but we could generate a best-case scenario
relatively easily and adjust in a pessimistic direction to
accommodate the inevitable delays in our best-laid plan. We
succumbed, as people commonly do, to the planning fallacy and
still underestimated how long it would take to finish (Buehler,
Griffin, & Ross, 1994). Interestingly, Tversky and Kahneman
(1974) foreshadowed this “planning fallacy”when suggesting
that people underestimate the likelihood of conjunctive events
because they tend to anchor on the likelihood of an initial
elementary event. “The general tendency to overestimate the
probability of conjunctive events,”they wrote, “leads to
unwarranted optimism in the evaluation of the likelihood that
a plan will succeed or that a project will be completed on time”
(Tversky & Kahneman, 1974, p. 1129).
When making predictions, the most accessible outcome is
often not the most likely event, but the one that is most
emotionally evocative (Morewedge, Gilbert, & Wilson, 2005)
or the one that is seen as most relevant to an individual's goals.
When predicting the time to complete a project, for instance,
people tend to focus on their good intentions rather than on
their past behavior (Koehler & Poon, 2006). These good
intentions can lead to the construction of a best-case scenario
that serves as an initial anchor that is subsequently adjusted to
arrive at a final prediction. In one experiment, for instance,
participants induced to accept values earlier in the process of
adjustment by making predictions while nodding their heads
up and down made more optimistic predictions than
participants who made their predictions while shaking their
heads from side to side (Rosenzweig, Epley, & Gilovich,
2009). In domains in which the outcomes are generally
positive, such best-case scenarios may serve as an initial
anchor. Sometimes, of course, the nature of the estimation
problem is such that it more naturally elicits a worst-case
scenario that serves as an anchor that biases estimates in a
pessimistic direction. Thus, participants in another experiment
(Rosenzweig et al., 2009) who watched the famous footage of
the Hindenberg crash and were asked to estimate the
percentage of passengers who perished tended to overestimate
the human carnage. But participants who were told they could
earn a cash bonus if their estimate was particularly accurate
made estimates that were indeed more accurate. This result is
consistent with the proposition that participants anchored on a
worst-case outcome (“no one could survive that”) but then
effortfully adjusted to take account of uncertainty—with the
more motivated participants adjusting more.
Incidental anchors
Most of the estimating people do is not in the laboratory but
out in the world, a world full of numbers. Speed limits. Sale
prices. Addresses. Because people are unlikely to deliberate
about any of these incidental numbers while estimating
completion times, inflation rates, or calories, their influence
on judgment—that is, their impact as anchors—is likely to be
relatively small. But their effect is not always zero. In one study,
participants said they would be willing to spend more for a meal
at Bistro 97 than Bistro 17. In another, participants estimated
that a higher percentage of global sales would occur in Europe
for a P97 cellphone than a P17 (Critcher & Gilovich, 2008).
One would think that these incidental anchors would
command no elaboration at all because they are understood to
be completely unrelated to the estimation task at hand. But the
context in which these incidental anchors are encountered might
matter. An attitudes and persuasion perspective can be useful
here. For example, might a p-17 offered by a high-prestige
brand attract more processing than one from a low-prestige
brand, increasing its impact on either the extremity or the
durability of people's judgments?
Environmental suggestion
Although anchoring researchers are generally careful to
avoid suggesting to participants via conversational norms
(Grice, 1975) that an anchor value is a clue to the right answer,
there is no doubt that such suggestion is a powerful influence on
anchoring effects in everyday life, just as Wegener et al. suggest
(see also Schwarz, 1994). The opening offer in a negotiation
(Galinsky & Mussweiler, 2001), the sentence proposed by a
lawyer in a criminal case (Englich & Mussweiler, 2001), or the
asking price of a house (Northcraft & Neale, 1987) are all
clearly suggestive of “the right”answer, and all produce reliable
anchoring effects. The incidental environmental anchors
discussed earlier do not require explicit consideration—the
first stage in the standard anchoring procedure—and yet they
still elicit anchoring effects. But other types of environmental
anchors are not incidental and convey not-so-subtle hints at the
“proper”response. For instance, supermarket shoppers bought
more Snickers bars when a sign suggested they buy “18 for their
freezer”than when it suggested they buy “some for their
freezer”(Wansink, Kent, & Hoch, 1998). The similarity
between these environmental suggestions and persuasion
contexts, as Wegener et al. note in their discussion of
conversational norms in the standard anchoring paradigm, is
obvious. The credibility of the source of these environmental
suggestions surely matters in terms of their impact on people's
evaluations and behavior.
22 N. Epley, T. Gilovich / Journal of Consumer Psychology 20 (2010) 20–24
Magnitude priming
Perhaps the most generally applicable sort of anchoring
effect in the existing literature is the demonstration that a
general sense of large or small magnitude can be primed in one
context and then influence people's estimates in another
(Oppenheimer et al., 2008). In one study, participants were
asked to reproduce three lines—a straight line, a squiggle, and
an inverted U. Some reproduced 1-in. versions; others 3.5-in.
versions. Those asked to reproduce longer lines subsequently
made higher numerical estimates of a target value on an entirely
different dimension—the average temperature in Honolulu in
July. In another study, participants who reproduced the long
lines were more likely to generate words synonymous with
“large”(e.g., turning _ALL into TALL instead of FALL) than
participants who reproduced the small lines. The key question
that an attitudes and persuasion approach (or any contextual
approach) can help address is when the initial task is likely to
activate such a general notion of large or small magnitude and
when it is likely to yield a mental representation that is tied so
directly to the task at hand that no general notion of large or
small is made accessible.
Concluding thoughts
An attitudes and persuasion perspective has the potential to
broaden research on anchoring in a way that unbinds it from a
concerted study of the standard anchoring paradigm and
examines anchoring in all of its everyday variety. We have
focused our comments on different varieties of anchoring to
which an attitudes and persuasion perspective may be applied,
but this perspective has the potential to broaden the study of
anchoring in two other important ways as well.
The first is in the study of additional moderators of anchoring
effects. Wegener et al. identified the credibility of an anchor's
source and people's confidence in their on-going thoughts as
plausible moderators of anchoring effects, but we suspect that
other social factors may prove important as well. For instance,
social status might influence the perceived credibility of an
anchor value and its source, with high status people often
granting others less credibility than low status people. A
person's status may therefore influence the amount of
elaboration on a particular anchor value. Social status is
orthogonal to a person's expertise in many domains, and is
central to nearly every social interaction in everyday life. It is
also likely to be central to many domains in which anchoring
effects have been shown to emerge, including negotiations,
legal judgments, and medical decision-making. Considering the
role of elaboration also highlights other social psychological
factors that may be likely to influence anchoring, including
accountability—that should influence the amount of elaborate
processing (Lerner & Tetlock, 1999; Kruglanski & Freund,
1983); self-affirmation—that should increase confidence in
one's own judgment and therefore influence the amount of
elaboration on self-generated and externally-provided anchors
(Sherman & Cohen, 2006); and even the mere presence of
others—that should increase the tendency to utilize dominant or
default responses in judgment and behavior (Blascovich,
Mendes, Hunter, & Salomon, 1999; Zajonc, 1965). Having
established anchoring as a reliable and powerful phenomenon in
judgment, these broader contextual moderators of anchoring are
now important to consider.
The second way that an attitudes and persuasion perspective
has the potential to broaden our understanding of anchoring is
through the study of its consequences. Understanding the
stability of attitudes is a central issue in the attitudes and
persuasion tradition, and Wegener et al. apply insights from
this perspective to the issue of the durability of anchoring
effects (see also Mussweiler, 2001). Another component of
the attitudes and persuasion research agenda has been to try
to understand when attitudes predict behavior and when they
do not. Generally, attitudes formed under high elaboration
tend to predict behavior better than those formed under low
elaboration. To date, anchoring as been studied as purely a
phenomenon of judgment; investigators have largely just
assumed that it can influence subsequent behavior, with very
little research devoted to examining its actual behavioral
impact. Although some existing research demonstrates that
anchoring can indeed influence behavior (e.g., Wansink et al.,
1998), such studies are notable exceptions. Now that
anchoring research is being applied more and more to both
consumer and policy domains, understanding its actual impact
on choice becomes increasingly important. An attitudes and
persuasion perspective provides clear guidance for this
research agenda, an agenda that we think holds considerable
promise.
The anchoring literature is now old enough that many
summaries of its findings have appeared, nearly all of which
highlight the importance of anchoring and its underlying
processes for so many areas of life that matter for social
psychology (e.g., Chapman & Johnson, 2002; Epley, 2004;
Mussweiler, 2003). We think an attitudes and persuasion
perspective on anchoring, sparked here by Wegener et al., is a
way for social psychology to “give back”to the JDM
community by identifying the ways in which anchoring is
likely to be influenced by a broader social psychological
perspective. This broadening is likely to keep anchoring
researchers productive for many years to come.
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