Leaf Van Boven is an Assistant Professor of Psychology at the University of Colorado, Boulder, Cam-
pus Box 345, Boulder, Colo. 80309. Email: vanboven@Colorado.edu. Thomas Gilovich is a
Professor of Psychology at Cornell University, Department of Psychology, Ithaca, N.Y. 15850. Email:
firstname.lastname@example.org. Victoria Husted Medvec is the Adeline Barry Davee Associate Professor of Man-
agement and Organizations at Northwestern University’s Kellogg School of Management, 2001
Sheridan Road, Evanston, Ill. 60201. Email:email@example.com.
0748-4526/03/0400-0117/0 © 2003 Plenum Publishing Corporation Negotiation Journal April 2003 117
The Illusion of Transparency in Negotiations
Leaf Van Boven, Thomas Gilovich,
and Victoria Husted Medvec
The authors examined whether negotiators are prone to an “illusion of
transparency,” or the belief that their private thoughts and feelings are
more discernible to their negotiation partners than they actually are. In
Study One, negotiators who were trying to conceal their preferences
thought that their preferences had “leaked out” more than they actually
did. In Study Two, experienced negotiators who were trying to convey infor-
mation about some of their preferences overestimated their partners’
ability to discern them. The results of Study Three rule out the possibility
that the findings are simply the result of the curse of knowledge, or the pro-
jection of one’s own knowledge onto others. Discussion explores how the
illusion of transparency might impede negotiators’ success.
In most cartoon depictions of negotiators in action (a tiny fraction of the
cartoon universe, we admit), negotiators are shown with dialog bubbles
depicting their overt comments and thought bubbles revealing their private
thoughts. These conventions convey the different levels at which negotia-
tors operate: Some of their wants, wishes, and worries are conveyed to the
other side, but some are held back for strategic advantage. Because one task
in negotiation is deciding how much information to hold back (Raiffa 1982),
it follows that part of the phenomenology of negotiation is monitoring how
well one has conveyed what one wants to convey and concealed what one
wants to conceal.
Do negotiators know how well they have conveyed or concealed their
preferences? Typically, negotiators know what they have and have not said,
of course, so they may generally have a good idea what their partners know
about their preferences. But how well calibrated are negotiators’ assess-
ments of what they have conveyed and concealed?
We explored one source of potential miscalibration, namely, whether
negotiators experience an illusion of transparency, overestimating the
extent to which their internal states “leak out” and are known by others
(Gilovich, Savitsky, and Medvec 1998). Most research on the illusion of trans-
parency shows that people overestimate their ability to conceal private
information. But there is also evidence that people experience the illusion
when trying to convey private information. Individuals who were asked to
convey emotions with facial expressions alone overestimated observers’ abil-
ity to discern the expressed emotion (Savitsky 1997). Likewise, participants
who were videotaped while exposed to humorous material thought they
had been more expressive than observers subsequently rated them as being
(Barr and Kleck 1995).
These findings suggest that, when trying either to conceal or convey
information, negotiators may experience an illusion of transparency, overesti-
mating what their partners know about their preferences. Whether they do
so is important, because previous research has shown that the likelihood of
(optimal) settlement is often contingent on accurate perceptions of what
others know about one’s own preferences (Bazerman and Neale 1992; Raiffa
1982; Thompson 1991).
We conducted three different studies to examine whether negotiators
experience an illusion of transparency in negotiations. Studies One and
Three examined whether novice negotiators trying to conceal their prefer-
ences tend to overestimate the likelihood that their negotiation partners
would be able to identify those preferences. Study Two investigated whether
experienced negotiators attempting to communicate some of their prefer-
ences also succumb to an illusion of transparency. Study Three was also
designed to distinguish the illusion of transparency from the “curse of
knowledge,” or the tendency to project one’s knowledge onto others
(Camerer, Loewenstein, and Weber 1989; Keysar and Bly 1995; Keysar,
Ginzel, and Bazerman 1995). Specifically, we examined whether observers
who are “cursed” with the same knowledge as the negotiators exhibit the
same biases as the negotiators themselves.
Twenty-four previously unacquainted Cornell University undergraduates par-
ticipated in pairs in exchange for course credit. Participants learned that
118 Van Boven, Gilovich, and Medvec The Illusion of Transparency in Negotiations
Negotiation Journal April 2003 119
they would complete a negotiation exercise in which they would each rep-
resent the provost at one of two campuses of a multi-campus university
system. Because of budget constraints, all of the system’s eight social psy-
chologists needed to be consolidated at the two provosts’ universities. The
provosts were to negotiate the distribution of the social psychologists
between the two campuses.
Participants were informed that some social psychologists were more
valuable than others, and that some were more valuable to one campus than
the other. These differences were summarized in a report describing the
strengths and weaknesses of each psychologist and assigning each a specific
number of points. The eight psychologists were among the fifteen most fre-
quently cited in social psychology textbooks (Gordon and Vicarii 1992). To
familiarize participants with the psychologist and his or her expertise, each
psychologist was depicted on a 2- by 4-inch laminated “trading card” that dis-
played a picture of the social psychologist, his or her name, and two of his or
her better-known publications.
Each negotiator’s most and least valuable psychologists were assigned
+5 and –5 points, respectively, and the other psychologists were assigned
intermediate values. The experimenter said that all psychologists must be
employed at one of the two universities because all were tenured. The most
and least valuable psychologists were not the same for the two negotiators;
the correlation between how much each of the eight psychologists was
worth to the two participants was .79. Participants were told that they
should conceal their report, which was somewhat different from the other
Because pilot testing indicated that many participants were unsure how
to negotiate, we showed them a five-minute videotape of a staged negotia-
tion in which two confederates bartered over who would get (or be forced
to acquire) each psychologist. Confederates were shown trading cards
actively back and forth.
Participants were given as much time as they needed to negotiate, usu-
ally about 30 minutes. They were told that several prizes would be awarded at
the end of the academic term (e.g., a $50 gift certificate to the Cornell book
store, dinner for two at a local restaurant) and their chance of winning a prize
corresponded to the number of points they earned in the negotiation.
We asked participants both early in the negotiation (after approximately
five minutes) and at the end to name their partner’s most valuable and least
valuable psychologists. At both times, we also asked them to estimate the like-
lihood (expressed as a percentage) that their partner would correctly identify
their most and least valuable psychologists. We pointed out that the probabil-
ity of correct identification by chance alone was 12.5 percent. Question order
was counterbalanced, with no effect of order in any of our analyses.
Results and Discussion
Our key analysis was a comparison of participants’ mean estimates to a null
value derived from the overall accuracy rate. Participants can be said to
exhibit an illusion of transparency if their estimates, on average, are higher
than the actual accuracy rate.
As predicted, negotiators overestimated their partners’ ability to detect
their preferences, but only after the negotiation was complete (see Table
One). Early in the negotiation, individuals slightly underestimated (by 2 per-
cent) the likelihood that their partners would correctly identify their most
valuable psychologist and slightly overestimated (by 8 percent) the likelihood
that their partners would identify their least valuable psychologist. Neither of
these differences was statistically reliable.1Following the negotiation, partici-
pants overestimated the probability that their partners would identify
correctly their most and least valuable psychologists by 14 percent and 13
percent, respectively. Both of these differences were statistically reliable. That
is, the probability that negotiators overestimated by pure chance how much
their partners knew about their preferences is less than .05 (the tstatistics for
these two comparisons are 3.16 and 3.30, respectively).2Negotiators thus
experienced an illusion of transparency at the end of the negotiation, overes-
timating their partners’ ability to discern their preferences.
Negotiators’ estimates of the likelihood that their partners would be able
to identify their most and least valuable social psychologists, and the cor-
responding percentages actually able to do so.
Estimated % Actual %
Most valuable 69% 71%
Least valuable 58% 50%
Most valuable 72%* 58%
Least valuable 76%* 63%
Note: * indicates that the estimated percentage is reliably greater than the corre-
sponding actual percentage, p < .05
120 Van Boven, Gilovich, and Medvec The Illusion of Transparency in Negotiations
Negotiation Journal April 2003 121
These findings extend earlier research on the illusion of transparency,
showing that negotiators believe their inner thoughts and preferences “leak
out” and are more discernible than they really are. This result was obtained
only during the second assessment, but we do not wish to make too much
of this finding. First, it is hardly surprising because, at the time of the initial
assessment, most groups had yet to engage in much discussion of specific
candidates, and thus there was little opportunity for participants’ prefer-
ences to have leaked out. Furthermore, it was only participants’ estimates of
the detectibility of their least valuable psychologists that rose predictably
(from 58 to 76 percent) from early in the negotiation to the end — an
increase that was highly statistically reliable (t= 3.78).
Their estimates of the detectibility of their most valuable psychologists
stayed largely the same across the course of the negotiation (from 69 to 72
percent) and it was only a decrease in identification accuracy (from 71 to 58
percent) over time that led to the difference in the magnitude of the illusion
of transparency. These subsidiary findings may result from the usual dynam-
ics of the negotiation process: Negotiators typically focus initially on the
most important issues, postponing a discussion of less important issues or of
what they are willing to give up to obtain what they want until later in the
negotiation. This would explain why negotiators felt that they had already
leaked information about their most important psychologists early in the
negotiation, but that a similar feeling of leakage regarding their least impor-
tant psychologists took longer to develop.
This tendency might also explain why it may have been relatively easy
for the negotiators to discern one another’s “top choices” early in the discus-
sion. It may have been harder to do so later on, after the negotiators
discussed all of the psychologists and the various tradeoffs between them.
In Study One, participants experienced an illusion of transparency when
they were instructed to conceal their preferences from their partners. In
many negotiations outside the laboratory, however, negotiators often
attempt to communicate rather than conceal their preferences. In fact, nego-
tiation instructors often advise MBAs and other would-be negotiators to
communicate information about their preferences.
Do negotiators experience an illusion of transparency when they
attempt to communicate rather than conceal their preferences? Past research
has shown that people experience an illusion of transparency when trying
(nonverbally) to convey thoughts and feelings in settings outside negotia-
tions (Barr and Kleck 1995; Savitsky 1997). We therefore examined whether
negotiators attempting to communicate some of their preferences, whose
efforts at communication are not limited to nonverbal channels, would like-
wise experience an illusion of transparency.
As part of a classroom exercise, MBA students in negotiation courses
completed a complex six-party negotiation simulation (Harborco, a teaching
tool available from the Clearinghouse of the Program on Negotiation at Har-
vard Law School, www.pon.org). The course emphasized the importance of
negotiators communicating some of their preferences to one another in
negotiations. Prior to the Harborco negotiation, students had engaged in
numerous other exercises in which their failure to convey information
resulted in nonoptimal settlements.
To verify that the Harborco negotiators were attempting to communi-
cate information about their preferences, we asked 22 Cornell and
Northwestern University MBA students (not included in following study)
who had just completed the Harborco negotiation to indicate which strategy
they engaged in more: an information-sharing strategy (attempting to com-
municate their preferences to others), or an information-hiding strategy
(attempting to conceal their preferences from others). Everyone indicated
that they used the information-sharing strategy more.
We hypothesized that the same psychological processes that lead
novice negotiators trying to conceal their preferences to experience an illu-
sion of transparency would also lead experienced negotiators trying to
communicate at least some of their preferences to experience a similar illu-
sion. We thus predicted that participants would overestimate the number of
other negotiators who could correctly identify their preferences.
Two hundred and forty MBA students at Cornell and Northwestern com-
pleted the Harborco simulation, negotiating whether, and under what
circumstances, a major new seaport would be built off the coast of a fic-
tional city. There were six parties to the negotiation. The negotiator who
represented Harborco (a consortium of investors) was most central. A sec-
ond negotiator, representing the federal agency that oversees the
development of such seaports, had to decide whether to subsidize a $3 bil-
lion loan Harborco had requested. The other negotiators represented the
state governor, the labor unions from surrounding seaports, the owners of
other ports that might be affected by a new seaport, and environmentalists
concerned about the impact of a new seaport on the local ecology.
The negotiation involved five issues, each with several options of vary-
ing importance to the six parties. For each negotiator, points were assigned
to each option of each issue. Student performance was evaluated according
to the number of points accumulated. For example, the most important
issue to the Harborco representative was the approval of the subsidized loan
(worth 35 points for approval of the full $3 billion, 29 points for approval of
a $2 billion loan, etc.); the second most important issue was the compensa-
tion to other ports for their expected losses due to the new seaport (worth
23 points for no compensation, 15 points for compensation of $150 million,
122 Van Boven, Gilovich, and Medvec The Illusion of Transparency in Negotiations
Negotiation Journal April 2003 123
etc.). The Harborco negotiator’s preference order for the five issues was
somewhat different from the preference order of the other five negotiators.
Participants were given approximately one and a half hours to reach an
agreement. They were required to vote on a settlement proposed by the Har-
borco negotiator at three points during the negotiation: after 20 minutes,
after one hour, and at the end. A successful agreement required the approval
of at least five negotiators. Any agreement that included the subsidized loan
required the approval of the federal agency representative. The Harborco
negotiator could veto any proposal.
The dependent measures, collected after the first and final rounds of vot-
ing, concerned the Harborco negotiator’s estimates of the other negotiators’
identification of his or her preference order. The Harborco negotiators esti-
mated how many of the other five negotiators would identify the rank
ordering (to the Harborco negotiator) of each issue — for example, how many
would identify the approval of the loan as their most important issue? We
made clear that one negotiator would guess the exact importance of each
issue by chance alone. Meanwhile, each of the other negotiators estimated the
issue that was most important to Harborco, second most important, and so on.
Predicted and actual number of negotiators able to identify correctly the
importance of each issue to the Harborco negotiator after the first and final
rounds of voting.
Results and Discussion
The dashed lines in Figure One indicate that, as predicted, the Harborco
negotiators’ estimate of the number of other negotiators who could identify
the rank of each issue was greater than the actual number of negotiators able
Number able to identify each issue
to do so (as indicated by the solid lines). Following the first round of voting,
the Harborco negotiators overestimated the number of their fellow negotia-
tors able to identify the importance — to them — of all mid-range issues. All
these differences were statistically reliable (all ts > 2.30). Negotiators did not
overestimate the number of negotiators able to identify their most and least
important issues. Following the final round of voting, Harborco representa-
tives overestimated the number of negotiators able to identify their four
most important issues. This overestimation was statistically reliable for the
four most important issues (all t> 2.25), and was marginally reliable with a
probability level of .14 for the least important issue (t= 1.5).
These findings replicate and extend those of Study One and of previous
research on the illusion of transparency. Experienced negotiators who were
attempting to convey (rather than conceal) their preferences to other nego-
tiators tended to overestimate the transparency of those preferences.
We contend that negotiators’ overestimation of their partner’s ability to dis-
cern their preferences reflects an egocentric illusion whereby negotiators
overestimate the transparency of their internal states. An alternative account
is that negotiators experience a “curse of knowledge,” overestimating the
knowability of whatever they themselves know (Camerer et al. 1989; Keysar
and Bly, 1995; Keysar et al. 1995).
Negotiators may thus overestimate the discernibility of their prefer-
ences because they cannot undo the knowledge of their own preferences,
not because they feel like their preferences “leaked out.” Studies One and
Two provide some evidence against this alternative interpretation because
participants did not significantly overestimate their partners’ ability to dis-
cern their preferences early in the negotiation — when they were “cursed”
with the same knowledge, but had little opportunity for their preferences to
To provide a more rigorous test of this alternative interpretation, Study
Three employed a paradigm in which observers were yoked to each individ-
ual negotiator. The observers were informed of their counterpart’s
preferences and thus were “cursed” with the same abstract knowledge, but
not with the phenomenology of having — and possibly leaking — the nego-
tiators’ preferences. After watching a videotaped negotiation between their
yoked counterpart and another negotiator, observers estimated the likeli-
hood that their counterpart’s negotiation partner would identify their
counterpart’s preferences. We expected that observers’ estimates would be
lower than actual negotiators’ estimates because observers would not have
the experience of their preferences “leaking out.”
124 Van Boven, Gilovich, and Medvec The Illusion of Transparency in Negotiations
Negotiation Journal April 2003 125
Twenty-four previously unacquainted Northwestern University undergradu-
ates participated in pairs in exchange for the opportunity to earn between
$4 and $13, based on their performance in the negotiation.
Negotiators were taken to separate rooms and given instructions for the
negotiation. The negotiation was similar to that used in Study One, except
that it involved a buyer-seller framework, with which we felt our participants
would be familiar. Participants learned that they would act as a provost of
one of two campuses of a large university system. Because of budget cuts,
the larger of the two campuses (the “seller”) needed to eliminate fifteen of
its 35 psychology department faculty. Because the fifteen faculty were
tenured, they could not be fired, but they could be transferred to the smaller
of the two campuses (the “buyer”), which was trying to acquire faculty.
Participants were to negotiate over the fifteen psychologists “in play”;
any faculty not acquired by the buyer would remain at the seller’s campus.
Participants were given a report that described each psychologist and his or
her associated point value. Some of the psychologists had a positive value to
buyers and a negative value to sellers, others had a positive value to both,
and still others had a negative value to both. Participants were told that they
should not show their confidential reports to the other negotiator.
Participants earned 25 cents for every positive point and had to pay 25
cents for every negative point they accumulated. To give buyers and sellers
an equal chance to make the same amount of money, we endowed sellers
with an initial stake of $10 and buyers with an initial stake of $4. If buyers
obtained all nine of the beneficial faculty and none of the four costly faculty
(two were worth 0 points) they earned an additional $8, for $12 total. Simi-
larly, if the sellers eliminated all eight costly faculty and retained all five
beneficial faculty (two were worth 0 points) they earned $2, for $12 total. If
no agreement was reached, sellers retained all faculty, losing $6, and buyers
acquired no psychologists, leaving both with $4.
As in Study One, we gave participants laminated trading cards with a
picture of each psychologist and two of that psychologist’s better-known
works on the back. The fifteen faculty members, although in reality all social
psychologists, were arbitrarily divided into the three subdisciplines of social,
clinical, and human-experimental psychology. We designed the payoffs so
that the psychologist within each discipline who the buyer most wanted to
obtain was not the psychologist the seller most wanted to eliminate.
To encourage participants to obtain or retain psychologists across the
three disciplines, sellers were offered an additional two points if they elimi-
nated at least one faculty member from each discipline, and an additional
four points if they eliminated at least two from each discipline. Similarly, buy-
ers were offered an additional two points if they acquired at least one faculty
member from each discipline, and an additional four points if they acquired
at least two from each discipline. Thus, maximum earnings for buyers and
sellers were $13 (the $12 earned by accumulating all possible positive
points, no negative points, plus the $1 bonus).
After negotiators understood their task, they were brought together and
given as long as they needed to negotiate a division of the fifteen psycholo-
gists, usually about 20 minutes. Afterward, buyers estimated the likelihood
(expressed as a percentage) that the seller would correctly identify the psy-
chologists from each subdiscipline who were the most and least important
for the buyer to obtain; sellers estimated the likelihood that the buyer would
correctly identify the psychologists from each subdiscipline who were the
most and least important for the seller to eliminate. Participants were told
that the chance accuracy rate was 20% percent.3Buyers were also asked to
identify the psychologists from each subdiscipline who were the most and
least important for the seller to eliminate, and sellers were asked to make
analogous judgments about the buyers’ incentive structure.
Control Condition. Twelve pairs of previously unacquainted North-
western undergraduates were paid $6 and “yoked” to one of the 12 pairs
from the negotiation condition — one student matched to the buyer and
one to the seller. Participants read the instructions given to their yoked coun-
terpart (either the buyer or seller) in the actual negotiation before viewing
their counterpart’s videotaped negotiation. Participants then made the same
estimates as their counterparts in the negotiation condition, identifying the
psychologists from each subdiscipline who were most and least important
for their counterpart’s negotiation partner to acquire (or eliminate), and esti-
mating the likelihood that their counterpart’s negotiation partner would be
able to guess the psychologists in each subdiscipline who were most and
least important for their counterpart to obtain (or eliminate).
Negotiators. As anticipated, negotiators exhibited an illusion of trans-
parency. As can be see in the left and right columns of Table Two, buyers
and sellers overestimated their partners’ ability to identify their most impor-
tant psychologists by 20 percent — both statistically reliable differences (ts=
3.58 and 3.45, respectively). Buyers and sellers also overestimated the likeli-
hood that their partner would be able to identify their least important
psychologists by 4 percent and 25 percent, respectively, with only the latter
result statistically reliable (t= 4.34).
Control participants. Control participants displayed a “curse of knowl-
edge,” overestimating the likelihood that their counterpart’s negotiation
partner would correctly identify their counterpart’s preferences (compare
the center and right columns of Table Two). This was particularly true for
126 Van Boven, Gilovich, and Medvec The Illusion of Transparency in Negotiations
Negotiation Journal April 2003 127
those yoked to sellers: They reliably overestimated the likelihood that their
yoked counterparts’ negotiation partners would identify their counterparts’
most and least important psychologists by 12 percent and 19 percent,
respectively (ts = 2.58 and 4.49). Control participants who were yoked to
buyers, in contrast, did not overestimate the likelihood that their yoked
counterparts’ negotiation partners would overestimate their counterparts’
Participants’ estimates of the likelihood that their negotiators’ partners were
able to identify the negotiators’ most and least important psychologists, and
the corresponding percentages actually able to do so.
Negotiators’ Control Actual
Estimates Estimates Accuracy
Buyers 70%* 53% 50%
Sellers 59%* 51%* 39%
Buyers 62% 56% 58%
Sellers 68%* 63%* 42%
Note: * indicates that the estimated percentage is reliably greater than the
corresponding actual percentage, p < .05
More important, in every case the control participants’ estimates (over-
all M= 56 percent) were lower than the actual negotiators’ estimates (overall
M= 64 percent) — a statistically reliable difference (t= 2.53). Thus, negotia-
tors overestimated the transparency of their preferences more than yoked
observers who were “cursed” with the same knowledge, but did not have
the same subjective experience as negotiators themselves.
The results of Study Three indicate that negotiators’ overestimation of their
partners’ ability to discern their preferences stems from both a curse of
knowledge and an illusion of transparency. Observers who were provided
with the same abstract knowledge as the negotiators — those provided with
abstract information about sellers’ preferences at any rate — overestimated
the likelihood that those preferences would be detected.
However, this effect was not as strong as that found for actual negotia-
tors’ estimates. Those participants, possessing more detailed knowledge
about how it felt to want to obtain some psychologists and avoid others,
apparently thought that some of those feelings had leaked out to their part-
ners because they made significantly higher estimates of the likelihood of
detection than the observers did. Negotiators experience an illusion of trans-
parency over and above any curse of knowledge to which they are subject.
What Does it All Mean?
These three studies provide consistent support for an illusion of trans-
parency in negotiations. Undergraduate students who were instructed to
conceal their preferences thought that they had “tipped their hand” more
than they actually had (Studies One and Three). Likewise, business students
experienced in negotiation who were attempting to communicate informa-
tion about some of their preferences overestimated how successfully they
had done so (Study Three). These results are not due to an abstract “curse of
knowledge” because observers who were cursed with the same knowledge
as the negotiators did not overestimate the detectibility of the negotiators’
preferences to the same extent as the negotiators did (Study Three). The illu-
sion of transparency is thus due to the sense that one’s specific actions and
reactions that arise in the give-and-take of negotiation — a blush here, an
averted gaze there — are more telling than they actually are.
These results complement and extend findings by Vorauer and Claude
(1998) who examined participants’ ability to estimate how well others could
discern their general approach to a joint problem-solving exercise — i.e.,
whether they were most interested in being assertive, being fair, being
accommodating, and so on. They found that participants thought their goals
would be more readily discerned than they actually were. Their findings,
however, appear to reflect a curse of knowledge rather than an illusion of
transparency because their participants’ estimates of the detectibility of their
own goals were just the same as those made by observers who were simply
informed of the participants’ goals.
The Vorauer and Claude findings should not be surprising since their
participants did not actually engage in face-to-face interaction. Instead, each
participant exchanged notes with a “phantom” other, whose responses were
crafted by the experimenters. Without interaction, it is difficult see how an
illusory sense of transparency could emerge. Vorauer and Claude’s studies,
along with the results of Study Three, suggest that the curse of knowledge
can likewise lead to exaggerated estimates of how readily one’s negotiation
partner can discern one’s own perspective on the negotiation (Keysar et al.
128 Van Boven, Gilovich, and Medvec The Illusion of Transparency in Negotiations
Negotiation Journal April 2003 129
It is important to note that both the illusion of transparency and the
curse of knowledge reflect people’s difficulty in getting beyond their privi-
leged information. In the curse of knowledge, this information is abstract
knowledge of one’s beliefs, preferences, or goals; in the illusion of trans-
parency, this information is more detailed, phenomenological knowledge of
how one feels or how difficult it was to suppress a particular reaction.
At one level, then, it may be fair to characterize the illusion of trans-
parency as a special case of knowledge — more detailed and affect-laden —
with which one is cursed. At another level, however, the differences
between the two phenomena may be sufficiently pronounced that there is
more to be gained by viewing them as distinct. Ultimately, a more complete
understanding of the relationship between the curse of knowledge and illu-
sion of transparency must await the outcome of further research.
Future research might also further examine the underlying mechanism
proposed for the illusion of transparency. Gilovich et al. (1998) attribute the
phenomenon to a process much like Tversky and Kahneman’s (1974)
anchoring and adjustment heuristic. When attempting to ascertain how
apparent their internal states are to others, people are likely to begin the
process of judgment from their own subjective experience. Because people
know that others are not as privy to their internal states as they are them-
selves, they adjust from their own perspective to capture others’
Because such adjustments tend to be insufficient (Tversky and Kahne-
man 1974; Epley and Gilovich 2001), the net result is a residual effect of
one’s own phenomenology, and the feeling that one is more transparent
than is actually the case. This account suggests that the illusion of trans-
parency should be particularly pronounced when the internal state being
assessed is one that is strongly and clearly felt, such as when negotiating
especially important issues.
In addition, future research might examine the impact of the illusion of
transparency on negotiation processes and outcomes. Thompson (1991) has
shown that when negotiators have different priorities, negotiators who pro-
vide information about their priorities to their partners fare better than those
who do not. The illusion of transparency may lead negotiators to hold back
information about their priorities in the mistaken belief that one has con-
veyed too much information already. By leading negotiators to believe that
their own preferences are more apparent than they really are, the illusion of
transparency may give rise to the belief that the other side is being less open
and cooperative than they are themselves — which may lead each negotiator
to hold back even more. The process can thus spiral in the wrong direction
toward greater secrecy.
It may be advantageous, then, for negotiators to be aware of the illu-
sion of transparency. If negotiators know they tend to conceal less than
they think they do, they may open up a bit more and increase their
chances of reaching optimal agreements. In other words, knowing that
one’s own “thought bubbles” are invisible to others can lead to more suc-
This research was supported by Research Grant SBR9319558 from the National Science Founda-
tion. We thank Tina Rackitt her help in collecting data and Dennis Regan for his comments on an
1. Because the data for each pair of negotiators are interdependent, all analyses in this and
subsequent studies used the dyad (or group) as the unit of analysis.
2. A t statistic is a measure of how extreme a statistical estimate is. Specifically, a t is the ratio
of the difference between a hypothesized value and an observed value, divided by the standard
error of the sampled distribution. Consider negotiators’ estimates, following the negotiation, that
their negotiation partner had a 72 percent chance of correctly identifying their most valuable psy-
chologist. Because, in actuality, negotiators identified their partners’ most valuable psychologist
only 58 percent of the time, the difference between the hypothesized value (58 percent) and the
observed value (72 percent) is 14 percent. The standard error, in this case, is the standard devia-
tion of the difference between a negotiators’ predicted likelihood and the actual likelihood (the
average squared difference between these two scores), divided by the square root of the sample
size. In general, t statistics more extreme than 1.96 are statistically reliable — that is, the probabil-
ity that the observed difference is due to chance alone is less than .05.
3. We also asked negotiators to estimate which subdiscipline was most important to their
partner, and to estimate the likelihood that their partner would discern correctly their own prefer-
ence order vis-à-vis the three subdisciplines. During debriefing, however, participants said they
found these questions confusing because they did not parse the 15 faculty according to their sub-
discipline, but instead focused on the value of each individual faculty. These responses are
therefore not discussed further.
Barr, C. L. and R. E. Kleck. 1995. Self-other perception of the intensity of facial expressions of
emotion: Do we know what we show? Journal of Personality and Social Psychology 68:
Bazerman, M. H. and M. Neale. 1992. Negotiating rationality. New York: Free Press.
Camerer, C., G. Loewenstein, and M. Weber. 1989. The curse of knowledge in economic settings:
An experimental analysis. Journal of Political Economy 97: 1232-1253.
Epley, N. and T. Gilovich. 2001. Putting adjustment back in the anchoring and adjustment heuris-
tic: An examination of self-generated and experimenter-provided anchors. Psychological
Science 12: 391-396.
Gilovich, T. D., K. K. Savitsky, and V. H. Medvec. 1998. The illusion of transparency: Biased assess-
ments of others’ ability to read our emotional states. Journal of Personality and Social
Psychology 75: 332-346.
Gordon, R. A. and P. J. Vicarii. 1992. Eminence in social psychology: A comparison of textbook
citation, social science citation index, and research productivity rankings. Personality and
Social Psychology Bulletin 18: 26-38.
Keysar, B. and B. Bly. 1995. Intuitions about the transparency of intention: Linguistic perspective
taking in text. Cognitive Psychology 26: 165-208.
Keysar, B., L.E. Ginzel, and M. H. Bazerman. 1995. States of affairs and states of mind: The effect of
knowledge on beliefs. Organizational Behavior and Human Decision Processes 64: 283-
Raiffa, H. 1982. The art and science of negotiation. Cambridge, Mass.: Harvard University Press.
130 Van Boven, Gilovich, and Medvec The Illusion of Transparency in Negotiations
Negotiation Journal April 2003 131
Savitsky, K. 1997. Perceived transparency of and the leakage of emotional states: Do we know
how little we show? Unpublished doctoral dissertation, Cornell University.
Thompson, L. 1990. An examination of naïve and experienced negotiators. Journal of Personality
and Social Psychology 26: 528-544.
———. 1991. Information exchange in negotiation. Journal of Experimental Social Psychology
Tversky, A. and D. Kahneman. 1974. Judgment under uncertainty: Heuristics and biases. Science
Vorauer, J. D. and S. Claude. 1998. Perceived versus actual transparency of goals in negotiation.
Personality and Social Psychology Bulletin 24: 371-385.