The halo effect—— Evidence for unconscious alteration of judgments

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 EFFECT 251 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 252 RICHARD 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 EFFECT 253 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 4 0 SUBJECTS 20 0 80 60 PERCEUT OF 4 0 SUBJECTS 20 0 80 60 PERCENT Of 4 0 SUBJECTS 20 WARM TEACHER I COLD TEACHER Physical Appearance Mannerisms Accent APPEAUW IRMTHIIC • • 1 APfOL IK 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. 254 RICHARD 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 4 0 SUBJECTS 20 80 60 PERCENT or 4 0 SUBJECTS 20 80 60 PERCENT OF 4 0 SUBJECTS 20 WARM TEACHER | COLO TEACHER Physical Appearonc* DECREASED »0 INOEASED RATH* EFFECT M T K DECREASED NO INCREASED RATUK EFFECT RATHX 60 PERCENT 4 0 Of SUBJECTS 2 0 PERCENT OF 4 0 SUBJECTS 20 60 PERCEUT OF 4 0 SUBJECTS 20 WARM TEACHER | COLD TEACHER Physical Appearance DECREASED M MOUSED RATNK EFFECT R O M 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 indicat