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Journal of Feisonality and Social Psychology
1977, Vol 35, No. 4, 250-256
The Halo Effect: Evidence for Unconscious
Alteration of Judgments
Richard E. Nisbett and Timothy DeCamp Wilson
University of Michigan
Two different videotaped interviews were staged with the same individual—a
college instructor who spoke English with a European accent. In one of the
interviews the instructor was warm and friendly, in the other, cold and distant.
The subjects who saw the warm instructor rated his appearance, mannerisms,
and accent as appealing, whereas those who saw the cold instructor rated these
attributes as irritating These results indicate that global evaluations of a person
can induce altered evaluations of the person's attributes, even when there is
sufficient information to allow for independent assessments of them. Further-
more, the subjects were unaware of this influence of global evaluations on
ratings of attributes. In fact, the subjects who saw the cold instructor actually
believed that the direction of influence was opposite to the true direction. They
reported that their dislike of the instructor had no effect on their ratings of
his attributes but that their dislike of his attributes had lowered their global
evaluations of him.
Although the halo effect is one of the oldest
and most widely known of psychological phe-
nomena, surprisingly little is known about its
nature. The halo effect is generally defined as
the influence of a global evaluation on evalua-
tions of individual attributes of a person, but
this definition is imprecise with respect to the
strength and character of the influence. At
one extreme, the halo effect might be due
simply to an extrapolation from a general
impression to unknown attributes. Global
evaluations might color presumptions about
specific traits or influence interpretation of
the meaning or affective value of ambiguous
trait information. Thus, if we like a person, we
often assume that those attributes of the per-
son about which we know little are also favor-
able.
(Politicians often seem to capitalize on
this tendency by appearing warm and friendly
but saying little about the issues.) Such a
phenomenon could best be described as a de-
The present research was supported by National
Science Foundation Grant BNS75-23191.
We are indebted to Eugene Borgida and Hersz
Zukier for their assistance and advice and to Lee
Ross for criticism of an early draft of the manuscript.
Requests for reprints should be sent to Richard E
Nisbett, Research Center for Group Dynamics, Insti-
tute for Social Research, University of Michigan, Ann
Arbor, Michigan 48106.
duction from an implicit personality theory
holding that "nice people tend to have nice
attributes and less nice people have less nice
attributes." Similarly, the global evaluation
may alter the interpretation of the meaning
or evaluation of ambiguous attributes. Thus,
if one is told that a warm and friendly person
is impetuous, a quite different set of behaviors
come to mind from those that occur when one
is told that the impetuous person is angry
and hostile. The evaluation of the attribute
impetuous may differ in the two cases, but
the difference could be a mere interpretive
one arising from the ambiguity inherent in the
term impetuous.
It is possible, however, that the halo effect
is a much more powerful phenomenon. Global
evaluations may be capable of altering percep-
tions of even relatively unambiguous stimuli,
about which the individual has sufficient in-
formation to render a confident judgment. For
example, a person's appearance may be per-
ceived as more attractive if we like the person
than if we do not. If so, then the halo effect
involves much more than influence on pre-
sumptions about attributes or interpretations
of the meaning of attributes, but extends to
alteration of judgments about attributes for
which we generally assume we are capable of
rendering independent assessments.
250
HALO EFFECT251
The literature to date on the halo effect
does not provide a clear picture of either the
strength or the nature of the phenomenon. Al-
though correlational studies are plentiful, they
do not serve to demonstrate even that the
phenomenon exists. In any array of trait rat-
ings,
correlations tend to be positive, that is,
affectively consistent, but it is always possible
that the correlations are based on veridical
social perception. For example, people with
more pleasant personalities may actually be
better looking on the average than people with
less pleasant personalities. Alternatively, peo-
ple's criteria for likability and good looks may
differ in such a way as to produce positive
correlations in the absence of any influence of
one judgment or the other. For example, a
college football player and a drama major
may have different criteria for both likability
and good looks in other males. The football
player may prize a hail-fellow-well-met style
and may regard brawn as essential to mascu-
line good looks. The drama major may favor
verbal wit and a lean, ascetic appearance. If
an open personal style and brawniness are
associated and if a witty style and lean, as-
cetic looks are associated, then both the foot-
ball player and the drama major might show
positive correlations between their judgments
of likability and looks, even though they give
high scores on both dimensions to utterly dif-
ferent people and even though neither judg-
ment has in any way influenced the other.
To demonstrate that global evaluations al-
ter evaluations of particular attributes re-
quires an experimental approach. There have
been two sorts of experimental studies in this
area. One type employs adjectives rather than
persons as the stimuli (e.g., Anderson, 1974;
Asch, 1946). This research supports the gen-
eralization that the evaluative rating given to
a trait adjective is a function of the total
adjective set in which it is embedded. In a
sense, then, the global evaluation alters the
evaluation of a particular attribute. But this
work suffices only to show that the total ad-
jective set may influence the meaning or eval-
uation of a particular adjective whose meaning
or value is somewhat ambiguous when con-
sidered in isolation, as in the example above
of the interpretation of the adjective im-
Petuous.
Another type of experimental study has
employed actual persons as the stimuli
(Clif-
ford & Walster, 1973; Dion, 1972; Dion,
Berscheid, & Walster, 1972; Miller, 1970),
but these studies suffice to show only the weak
"altered presumption" version of the halo ef-
fect because they provide extremely impover-
ished information about the attributes to be
rated. For example, Miller (1970) gave photo-
graphs of attractive and unattractive target
persons to subjects and asked them to rate the
personalities of the target persons. Attractive
people were ascribed more favorable traits
than unattractive people, but this merely
constitutes a demonstration that people's im-
plicit personality theories include the assump-
tion that physically attractive people have
more attractive personalities. A convincing
demonstration of the strong version of the
halo effect phenomenon would require giving
subjects sufficient information on the attri-
butes to be rated to allow for an independent
assessment of the attributes.
One study in the above tradition went sub-
stantially further. Landy and Sigall (1974)
showed that evaluations of an essay given by
male college students were substantially
higher when the alleged writer of the essay
was an attractive woman than when the al-
leged writer was an unattractive woman. The
effect was very pronounced, especially when
the essay was of relatively poor quality. This
study supports the stronger interpretation of
the halo phenomenon because, unlike the
attributes in the above studies, the subjects
had information about the woman's essay that
was entirely sufficient to allow for an inde-
pendent assessment of its quality. The Landy
and Sigall study, however, was not precisely
a study of the halo effect because it was a
single attribute rather than a global evalua-
tion that was manipulated and a person's
product rather than an attribute that was
measured.
The present experiment was designed to
address an additional issue—the question of
people's awareness of the halo effect. Nisbett
and Wilson (1977) have recently argued that
people have little awareness of the nature or
even the existence of the cognitive processes
that mediate judgments, inferences, and the
production of complex social behavior. The
252RICHARD E NISBETT AND TIMOTHY
DECAMP
WILSON
halo effect would appear particularly likely
to be such a subterranean, unrecognized
process. If people were capable of rendering
independent assessments of attributes, they
would surely do so. The halo effect, particu-
larly if it is the strong, distorting influence
postulated by some theorists, would appear
to depend upon lack of awareness for its
existence. On the other hand, it is not incon-
ceivable that subjects might actually be able
to report correctly on its operation if they
were directly questioned about it (e.g., Oh
yes,
now that you mention it, maybe part of
the reason I liked his looks was because I
liked his personality). The present experiment
directly assessed people's reports about the
nature and direction of the influence of global
evaluations on evaluations of attributes.
Method
Overview
College student subjects were asked to evaluate a
psychology instructor, whom they viewed in a video-
taped interview, on several dimensions The subjects
were told that the investigators were studying the
possibility that ratings of an instructor presented in
such a brief fashion might resemble ratings by stu-
dents who had taken an entire course with the in-
structor The subjects were shown one of two differ-
ent interviews with the same instructor, a native
French-speaking Belgian who spoke English with a
fairly pronounced accent. In one interview, the in-
structor presented himself as a likable teacher, re-
spectful of his students' intelligence and motives,
flexible in his approach to teaching, and enthusiastic
about his subject matter In the other interview, he
appeared to be quite unlikable, cold and distrustful
toward his students, rigid and doctrinaire in his
teaching style. After viewing the videotaped inter-
view, the subjects rated the instructor's likability,
as well as the attractiveness of his physical appear-
ance,
his mannerisms, and his accent In order to
explore the question of subject awareness, some sub-
jects were then asked whether the instructor's likabil-
ity had affected their ratings of his appearance, man-
nerisms, and accent. Others were asked the reverse
question, namely, whether their evaluation of his
appearance, mannerisms, or accent had affected their
ratings of his likability. It was anticipated that the
subjects would rate the instructor as having a more
attractive physical appearance, more attractive man-
nerisms, and a more attractive accent when he was
likable than when he was unlikable It was also an-
ticipated that the subjects would be unaware of these
effects on their judgments and would deny that their
global evaluation of the instructor had affected their
other ratings.
Procedure
The subjects were 118 University of Michigan stu-
dents enrolled in introductory psychology; 62 were
males and 56 were females. The results for the two
sexes were entirely similar and therefore were com-
bined for presentation. The subjects participated in
the experiment in groups of 6-17. Sessions were con-
ducted in such a way as to insure that no overt
communication between subjects took place. (But in
any case, conclusions are not affected when the group
rather than the individual was used as the unit of
analysis.) On arrival, the subjects were ushered into
a well-appointed conference room with chairs oriented
toward a 19-inch (.48-meter) television monitor.
The subjects were told that the psychology depart-
ment had recently conducted a large-scale evaluation
of teachers of introductory psychology:
At the end of the term teachers were evaluated by
their students on a number of dimensions, ranging
from traditional questions of teaching effectiveness
to questions about matters such as physical ap-
pearance and mannerisms We are interested in
finding out whether evaluations of teachers who
are seen in brief videotaped interviews at all re-
semble the evaluations of these teachers by students
who were exposed to them for a whole semester.
We will ask you to look at these videotapes and
then rate the teachers on some of the same dimen-
sions employed in the original study.
The subjects were then shown two videotaped in-
terviews All subjects were first shown a 7-minute
filler interview with a bright and pleasant instructor
who answered such questions as, What is your gen-
eral educational philosophy? Do you encourage stu-
dent discussion? How do you handle evaluations of
student work? Then half the subjects saw the Bel-
gian instructor answer the same questions in his
warm guise and half saw him answer the questions
in his cold guise Each of these interviews also lasted
about 7 minutes.
The warmness or coldness of the instructor was ap-
parent in his answers to virtually all the questions
For example, in his warm guise the instructor an-
swered the question about student discussion by say-
ing that, yes, he encouraged discussion and that he
was stimulated by the give and take it provided and
felt that it enhanced student interest in the lecture
material. In his cold guise he answered the question
by saying that he didn't allow much discussion be-
cause "there's a time to be a student and a time to
be a professor" and he wouldn't be the professor if
he didn't know more than they did. In his warm
guise the instructor answered the question about
evaluation of student work by saying that he gave
paper assignments that the students seemed to like
and profit from and gave exams that were a mixture
of objective questions and thought questions. In his
cold guise he said he gave weekly multiple-choice
quizzes because otherwise "y°u can't trust them to
do the reading."
HALO EFFECT253
Dependent Measures
After seeing each interview, all subjects were asked,
"How much do you think you would like this
teacher?,"
and were asked to rate him on an 8-point
scale ranging from "like extremely" to "dislike ex-
tremely." The questionnaire then read: "Listed below
are some characteristics of the teacher you saw.
Please indicate how you think you would feel about
each of the characteristics if you were to take a
course from the teacher" The characteristics in-
cluded physical appearance, mannerisms, and for the
Belgian instructor, accent. The subjects rated each
characteristic on the scale below:
— extremely appealing
— very appealing
— somewhat appealing
— slightly appealing
— slightly irritating
— somewhat irritating
— very irritating
— extremely irritating
In addition, 34 subjects were told that the investi-
gators were interested in knowing "how much, if at
all, your liking for the teacher influenced the ratings
you just made." The subjects indicated their answers
on scales of the following type:
My liking for the teacher caused me to rate his
physical appearance:
much higher
higher
slightly higher
had no effect
slightly lower
lower
much lower
Another 56 subjects were asked to indicate "how
much, if at all, the characteristics you just rated in-
fluenced your liking of the teacher." The subjects
indicated their answers on scales of the following
type:
Physical appearance made me like him:
much more
more
slightly more
had no effect
slightly less
less
much less
After responding to the questionnaire, the subjects
were quizzed intensively about their reactions to the
videotapes and to the questionnaire items, and then
were debriefed.
Results
Effect
of
Global
Evaluation
on
Evaluations of Attributes
The manipulation had a very pronounced
effect on liking of the teacher. The t value
contrasting the warm condition mean of 5.48
with the cold condition mean of 3.18 is 8.62
(df =
1/117,
p <
.00001
).1
Figure 1 presents
ratings of physical appearance, mannerisms,
and accent as a function of the liking manipu-
lation. For ease of presentation, all of the
positive (appealing) ratings are grouped to-
gether and contrasted with the negative (ir-
ritating) ratings. A small number of subjects
checked the point intermediate between ap-
pealing and irritating, and these subjects are
included with the irritating ratings. It may be
seen that the effect of the manipulation on at-
tribute ratings was very pronounced. A sub-
stantial majority of the subjects who saw the
teacher in his warm guise rated his physical
appearance as appealing, whereas a substan-
tial majority of those who saw him in his cold
guise rated his appearance as irritating (t =
4.71,
df - 1/H7, p < .00001). A majority of
warm condition subjects rated the teacher's
mannerisms as appealing, whereas a majority
of cold condition subjects rated bis manner-
isms as irritating (I = 4.06, df -
1/117,
p <
.0001).
About half the warm condition sub-
jects rated the teacher's accent as appealing
80
60
PERCENT
OF
40
SUBJECTS
20
0
80
60
PERCEUT
OF
40
SUBJECTS
20
0
80
60
PERCENT
Of
40
SUBJECTS
20
WARM TEACHER
I
COLD TEACHER
Physical Appearance
Mannerisms
Accent
APPEAUW IRMTHIIC
• •
1
APfOLIK IRRITATIHC
Figure 1. Ratings of Teacher's Physical Appearance,
Mannerisms, and Accent as a Function of Manipu-
lated Warmth versus Coldness.
1 All p values are based on two-tailed tests.
254RICHARD E. NISBETT AND TIMOTHY
DECAMP
WILSON
and half as irritating, whereas the overwhelm-
ing majority of subjects in the cold condition
rated his accent as irritating (* = 3.78, df —
1/117,
p< .0002).
The results demonstrate that global assess-
ment of a person can powerfully alter evalua-
tions of particular attributes. That is, this is
the case if one is willing to make the assump-
tion that the attributes manifested by the
confederate were in fact constant across ex-
perimental conditions. Although this is a rea-
sonable assumption, it is by no means indis-
putable. It might have been the case, for
example, that the teacher smiled a lot in his
warm guise, thus making his appearance more
appealing and/or frowned a lot in his cold
guise, thus making it less appealing. Similarly,
his mannerisms, both physical and verbal,
might have differed when he was playing the
two roles. It is even conceivable that his ac-
cent might have been less pronounced and
harsh when he was playing the warm role
than when playing the cold role.
In order to demonstrate that the teacher's
physical appearance did not in fact differ
across the two conditions, a follow-up study
was conducted with 34 subjects from the same
introductory psychology pool. These subjects
80
60
Kucat
Of
40
SUBJECTS
20
80
60
PERCENT
or 40
SUBJECTS
20
80
60
PERCENT
OF
40
SUBJECTS
20
WARM
TEACHER
|
COLO TEACHER
Physical
Appearonc*
DECREASED
»0
INOEASED
RATH*
EFFECT
MTK
DECREASED
NO
INCREASED
RATUK EFFECT RATHX
60
PERCENT
40
Of
SUBJECTS
20
PERCENT
OF
40
SUBJECTS
20
60
PERCEUT
OF
40
SUBJECTS
20
WARM
TEACHER
|
COLD
TEACHER
Physical
Appearance
DECREASED
M
MOUSED
RATNK EFFECT
ROM
DECEASED
M
INCREASED
RATHK EFFECT BATIK
Figure 2. Reported Effect of Teacher Likability on
Ratings of Physical Appearance, Mannerisms, and
Accent.
Figure 3. Reported Effect of Reactions to Physical
Appearance, Mannerisms, and Accent on Ratings of
Likability of Teacher.
were shown the interviews minus the audio
portions (purportedly for a study of nonverbal
communication) and were then asked to rate
the physical appearance of the teacher, as well
as his mannerisms. The subjects shown the
warm version rated the teacher's physical ap-
pearance and mannerisms only trivially higher
than the subjects shown the cold version (for
both, t < 1). This indicates that the physical
appearance and nonverbal mannerisms of the
teacher did not in fact differ across conditions.
Thus,
it can be assumed that the ratings of
physical appearance for the original subjects
differed solely because of the global affective
difference induced by the audio portion of the
interview.
Awareness of the Influence of
Global Evaluation
The subjects were apparently unaware of
the nature of the influence of global evalua-
tion on their ratings. Thirty-four of the sub-
jects were asked if their liking for the teacher
had affected their ratings of his attributes.
Figure 2 presents these subjects' answers to
this question. For ease of presentation, the
data are divided into three categories: (a)
decreased rating (representing 3 scale points),
(b) no effect (representing 1 scale point), and
(c) increased rating (representing 3 scale
points). It may be seen that a majority of
HALO EFFECT255
subjects, in both the warm and cold condi-
tions,
believed that their overall liking for
the teacher had not influenced their ratings.
Moreover, for all ratings in both conditions,
as many subjects felt that their overall evalu-
ation had increased their ratings as believed
it had decreased their ratings. None of the
distributions differs significantly from the
zero,
no effect point (all six one-sample ts
not significant).
Fifty-six subjects were asked if their evalu-
ations of the teacher's appearance, manner-
isms,
or accent had affected their liking of the
teacher. Figure 3 presents the results. It may
be seen that the subjects who saw the warm
teacher were divided on the question of
whether the ratings of particular attributes
affected liking. Only for the physical appear-
ance question did the majority of subjects
express the opinion that appearance had had
no effect on liking. For the other two ques-
tions,
approximately equal numbers of sub-
jects believed that the ratings had increased,
decreased, or had no effect on liking. None of
the three distributions differs significantly
from a mean of zero.
For the subjects who saw the cold teacher,
the results were quite different. On balance,
the subjects believed that their evaluations of
each of the three attributes had decreased
their liking for the teacher. The mean of all
three distributions differs from zero (t for
physical appearance = 3.28, p < .01; t for
mannerisms = 2.80, p < .01; / for accent =
2.74, p < .01).
Thus,
the subjects appear to have gotten
matters precisely backwards. Their liking for
the teacher was manipulated, and this affected
their ratings of particular attributes. Yet the
subjects did not acknowledge this effect, and
the subjects who saw the cold teacher actually
reported the opposite effect. These subjects
reported that their evaluations of the teacher's
attributes lowered their liking for him, al-
though they denied that their liking for the
teacher had affected their ratings of his attri-
butes.
(Logically, of course, it is possible that
the subjects who saw the cold teacher are
partly right. It is conceivable that the
teacher's appearance, mannerisms, and accent
were all intrinsically unattractive. In that
event, the subjects who saw the cold teacher
might have been accurate when they reported
that their liking for the teacher was decreased
because of their evaluations of these attri-
butes.
If that were the case, then the subjects
in the warm condition erred in believing that
the teacher's appearance, mannerisms, and
accent were neutral and had had no effect on
their liking of him.)
Conversations with the subjects following
the experiment served to reinforce the implica-
tions of Figures 2 and 3. The subjects were
asked if they were quite sure that their global
evaluations had not influenced their ratings of
the teacher's attributes. Most subjects per-
sisted in their denial—some warily, perhaps
because the}' suspected the experimenter knew
something they didn't, and some heatedly.
One young woman said, in a somewhat ex-
asperated tone, "Before he even began talk-
ing, I made my judgment about his appear-
ance and then I stuck with it." The
conversations gave reason to suspect, in fact,
that some of the subjects in Figure 2 who re-
ported that their liking for the teacher had
influenced their ratings did not actually be-
lieve this. One of the subjects who had indi-
cated this said, on being probed about his
answer: "Actually, I just turned the question
around I disliked his accent a little, so that
made me dislike him more."
Discussion
The present results support the strong in-
terpretation of the halo effect phenomenon.
They indicate that global evaluations alter
evaluations of attributes about which the in-
dividual has information fully sufficient to
allow for an independent assessment. These
results, it should be noted, are consistent with
the very earliest theorizing about the phe-
nomenon. Thorndike (1920), who gave the
phenomenon its name, clearly believed that
it represented far more than an effect on
presumptions about or interpretations of the
evaluative meaning of attributes, but rather
that it represented a fundamental inability
to resist the affective influence of global
evaluation on evaluation of specific attri-
butes.
Subsequent theorists have tended to
share this view, though in the absence of
strong evidence to support it.
256RICHARD E NISBETT AND TIMOTHY
DECAMP
WILSON
The layman has probably never doubted
the existence of an inability to separate evalu-
ations of attributes from global evaluations,
at least at the affective extremes (and so long
as he was referring to the foibles of others).
The strong interpretation of the halo effect is
embedded in such sayings as "love is blind"
and "a face only a mother could love." The
present study, however, suggests that global
evaluations may have a pronounced impact on
evaluations of specific attributes even when
the global evaluations in question are less ex-
treme than love and hate.
The present results, and those of Landy and
Sigall (1974), also provide prima facie evi-
dence that people lack awareness of the in-
fluence of one evaluation on another. Indeed,
it would appear that the altered judgments
require the absence of awareness. The sub-
jects in the present study would surely have
been disconcerted to know that they were in-
capable of rendering an independent evalua-
tion of such characteristics as physical appear-
ance,
mannerisms, and accent. They would
have been disconcerted, that is, if they could
have been persuaded that they had been in-
fluenced by their global evaluation. The sub-
jects were quite unfazed by the debriefing,
probably because each subject exempted him-
self from the accusation that he had been
prone to such an influence. The subjects in
the Landy and Sigall (1974) study would un-
doubtedly have been even more horrified if
they could have been convinced that they had
upgraded their evaluations of the essay of an
attractive woman or downgraded their evalua-
tions of the essay of a plain woman.
But the prima facie case is not the only
one that can be made. The subjects in the
present study were directly quizzed about
their beliefs concerning the nature and direc-
tion of influence. They overwhelmingly re-
ported that their ratings of particular attri-
butes had not been affected by their global
evaluations. The subjects who saw the cold
instructor actually believed that the influence
ran in the opposite direction—that their dis-
like of the teacher's attributes prompted their
unfavorable global evaluation.
When considering the establishment of
rules concerning blind review, conflict of in-
terest, nepotism, and the like, it would there-
fore seem advisable to consider more than the
possibility that some individuals in the system
may be venal and corrupt. The protestations
of even the most virtuous and disinterested
participants that they are capable of inde-
pendent judgments should be considered sus-
pect.
References
Anderson, N. H. Information integration theory: A
brief survey. In D H. Krantz, R. C. Atkinson,
R. D. Luce, & P Suppes (Eds.), Contemporary
developments
in
mathematical
psychology
(Vol. 2).
San Francisco: Freeman, 1974.
Asch, S. E. Forming impressions of personality. Jour-
nal of Abnormal and Social Psychology, 1946, 41,
258-290.
Clifford, M. M., & Walster, E. The effect of physical
attractiveness on teacher expectations. Sociology of
Education, 1973, 46, 248-258.
Dion, K K Physical attractiveness and evaluation of
children's transgressions Journal of Personality
and Social Psychology, 1972, 24, 207-213
Dion, K. K., Berscheid, E., & Walster E. What is
beautiful is good. Journal of Personality and So-
cial Psychology 1972, 24, 285-290
Landy, D., & Sigall, H. Beauty is talent: Task evalu-
ation as a function of the performer's physical at-
tractiveness. Journal of Personality and Social
Psychology, 1974, 29, 299-304.
Miller, A G. Role of physical attractiveness in im-
pression formation. Psychonomic Science, 1970, IP,
241-242
Nisbett, R. E., & Wilson, T. D. Telling more than we
can know: Verbal reports on mental processes.
Psychological Review, 1977, 7, 231-259.
Thorndike, E. L A constant error in psychological
ratings. Journal of Applied Psychology, 1920, 4,
25-29.
Received August 30, 1976 •
