Journal of Nonverbal Behavior 26(3), Fall 2002 � 2002 Human Sciences Press, Inc. 159

ACCURACY AND CONFIDENCE ON THEINTERPERSONAL PERCEPTION TASK:A JAPANESE-AMERICAN COMPARISON

Yuichi Iizuka, Miles L. Patterson, and James C. Matchen

ABSTRACT: This study compared the accuracy and confidence of Japanese andAmerican participants on the Interpersonal Perception Task (IPT-15). The IPT con-tains 15 brief, real-life scenes on videotape for which there are objectively correctanswers about relationships and deception. A total of 344 participants were run in a2 (Japanese vs. American participants) � 2 (Audiovisual vs. Visual-Only presenta-tion) � 2 (Sex of participant) design. Support was found for the hypothesizedgreater accuracy of Americans over Japanese, but a Culture � Presentation Modal-ity interaction qualified the main effect of culture. Specifically, Japanese and Ameri-can participants had virtually identical scores on the IPT-15 in the Visual-Only con-dition, but Americans’ scores increased while Japanese scores decreased in theAudiovisual condition. Analyses of the confidence measures indicated that Ameri-can participants were much more confident than the Japanese participants, but thisdifference was larger in the Audiovisual condition than in the Visual-Only condi-tion. In addition, the prediction that women would be more accurate on the IPT,but still report lower confidence than men, was also supported. Finally, Japaneseparticipants with moderate proficiency in spoken English were more accurate onthe IPT than those with low English proficiency. The likely processes underlyingthese differences and the possible directions for future research are discussed.

KEY WORDS: confidence; culture; person perception.

How we form impressions of other people has long been an importantissue in social psychology. Early attribution theories assumed that per-ceivers were information processors who assimilated input and logicallyapplied rules of inference (e.g., Heider, 1958; Jones & Davis, 1965). Thus,according to this perspective, the deliberate and controlled judgments made

Yuichi Iizuka, Shimane Nursing College. Miles L. Patterson and James C. Matchen, Uni-versity of Missouri–St. Louis.

The first and second authors contributed equally to the completion of this project.Address correspondence regarding to Yuichi Iizuka, Shimane Nursing College, 151

Nishihayashigi-cho, Izumo, Shimane 693-8550, Japan; e-mail: iizuka�shimane-nc.ac.jp; orto Miles L. Patterson, Department of Psychology, University of Missouri–St. Louis, St. Louis,MO 63121-4499; e-mail: miles patterson�umsl.edu.

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by perceivers were time consuming and effortful. In recent years, however,a growing body of research indicates that a wide range of judgments aretypically automatic in nature and outside of awareness (Bargh, 1994; Bargh& Chartrand, 1999; Smith, 1990; Zebrowitz & Collins, 1997). In fact, accu-rate judgments of others are possible after seeing slices of behavior lastingonly a few seconds (Ambady, Bernieri, & Richeson, 2000; Ambady & Ro-senthal, 1992). If such rapid judgments typically do determine the courseof person perception, this is possible only because there is adequate, reli-able information about individuals in their appearance and nonverbal be-havior.

Although there are different ways of studying person perception accu-racy from appearance and nonverbal behavior, one particularly usefulmethod is the Interpersonal Perception Task (Costanzo & Archer, 1989).The original Interpersonal Perception Task (IPT) consists of 30 videotapedscenes about which participants have to answer interpretive questions,such as, who won the tennis match the two men are talking about or whatis the relationship between the two people in the scene. Because these arereal life scenes, there are objectively correct answers about the people inthe scenes. Transparent verbal clues are edited out of the scenes so thatperceivers have to rely primarily on the nonverbal and vocal cues of thepeople in the scenes.

In recent years, a number of studies have examined factors that affectaccuracy and confidence on the IPT. As might be expected, an audiovisualpresentation of the IPT resulted in higher accuracy than a visual-only pre-sentation (Patterson & Stockbridge, 1998; Smith, Archer, & Costanzo, 1991).Nevertheless, because participants in the visual-only condition had higherthan chance levels of accuracy, appearance and behavioral cues still pro-vided valid information about the people in the scenes. Several studieshave examined sex differences in accuracy and confidence on the IPT. Theresults of two studies indicated that women were significantly more accu-rate than men (Costanzo & Archer, 1989; Smith, Archer, & Costanzo, 1991).Nevertheless, men reported significantly higher levels of confidence intheir answers. In two more recent studies, however, no differences werefound in accuracy between men and women on the IPT (Patterson, Foster,& Bellmer, 2001; Patterson & Stockbridge, 1998).

Culture and Judgment Accuracy

Although there is no research that explicitly examines the effect of cultureon IPT accuracy, there is extensive work on culture and other kinds of

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social judgments. For example, the role of culture has been especially im-portant in research on facial expression and emotion. Although there isclearly some similarity in the way that people from different cultures iden-tify facial expressions of basic emotions (e.g., happiness, sadness, anger,fear, surprise, and disgust), the extent of communality is a matter of consid-erable debate (see Ekman, 1994; Izard, 1994; Russell, 1994, 1995). Eventhough this issue might be framed as one of accuracy in the judgment ofemotional expressions, the methodology commonly used in this research—identifying emotions from highly expressive still photographs—is not rep-resentative of what typically happens in making social judgments. That is,in social settings, we make judgments of people from a sample of theirbehavior over a slice of time.

Unfortunately, there seems to be relatively little research examiningcultural differences in judgment accuracy based on such samples of socialbehavior. There are some cross-cultural data on the Profile of NonverbalSensitivity (PONS), a videotape test of sensitivity to nonverbal behaviorcontained in the face, body, and tone of voice (Rosenthal, Hall, Archer,DiMatteo, & Rogers, 1979). The scenes on the PONS, averaging approx-imately two seconds each, consisted of a twenty -four year old Caucasianfemale from the northeastern United States enacting a wide range of scenesdepicting specific emotions and social situations. Comparisons among par-ticipants from the United States and from twenty other nations indicatedthat cultures rated as most similar to that of the United States were moreaccurate in their judgments than were those that were less similar, r � .70(Rosenthal et al., 1979).

In another study, Greek and American participants viewed videotapedinteractions and judged the interactants’ level of rapport (Bernieri & Gillis,1995). The results showed that the average correlation between interac-tants’ self-reported rapport and observers’ judgments was approximatelyr � .20 for both Greek and American participants (Bernieri & Gillis, 1995).Although both Greeks and Americans apparently focused on some behav-iors that were valid indicators of rapport in the interactions, they also reliedon other behaviors, such as smiling and expressiveness, that were not validindicators of rapport. In a study of deception, American and Jordanian par-ticipants judged the truthfulness of videotaped statements made by bothAmerican and Jordanian targets. Although Americans and Jordanians wereslightly better than chance in discriminating the truth from lies in targetsfrom their own cultures (approximately 55% accuracy), both groups wereat chance levels in discriminating the truth from lies in targets fromthe other culture (Bond, Omar, Mahmoud, & Bonser, 1990). Thus, within-culture detection was better than cross-culture detection.

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The Present Study

Because there are no published accounts of using the IPT on groups out-side of the United States, we were interested in testing people in a non-Western culture where English was not commonly spoken. We were alsointerested in further examining the effect of participants’ sex on both accu-racy and confidence in another culture. In particular, we examined theaccuracy and confidence of Japanese and American participants who viewedthe IPT either with or without the accompanying audio track. That is, therewere two presentation modes: Audiovisual and Visual-Only. In this study,the IPT-15 (Costanzo & Archer, 1993), a shortened version of the originalIPT-30, was used. Because the Japanese participants saw interactions in-volving North Americans speaking English, it was not clear how much theycould understand and correctly interpret. Although the languages and thecultures are different, it is also obvious that many Japanese have someexposure to American culture through television. In addition, there may besome universal patterns of interactive behavior that transcend cultural dif-ferences.

Nevertheless, it was likely that the Japanese would be at a disadvan-tage in judging the scenes. Thus, our first hypothesis was that Americanparticipants would have higher accuracy and confidence on the IPT. Theaccuracy prediction is also consistent with the research on the PONS acrossa variety of different cultures (Rosenthal et al., 1979) and with the Bond etal. (1990) results showing better deception detection within than acrosscultures. Second, on the basis of results from two studies showing higherlevels of accuracy on the IPT in the audiovisual mode than in the visual-only mode (Patterson & Stockbridge, 1998; Smith, Archer, & Costanzo,1991), we hypothesized that both American and Japanese participantswould be more accurate in the Audiovisual condition than in the Visual-Only condition. Although both the Americans and Japanese were predictedto be more accurate in the Audiovisual condition than in the Visual-Onlycondition, we also expected a larger effect of presentation modality for theAmerican participants than for the Japanese participants because the indi-viduals in the IPT spoke English and most of the Japanese participants werenot very proficient in spoken English. Thus, the third hypothesis, a Cul-ture � Presentation Modality interaction effect, was based on the assump-tion that the American participants in the Audiovisual condition wouldbenefit from both content and vocal information (e.g., loudness, tone ofvoice, and intonation), whereas the Japanese were likely to benefit onlyfrom the vocal cues. On the basis of earlier studies on the IPT (Costanzo &Archer, 1989; Patterson, Foster, & Bellmer, 2001; Smith, Archer, & Cos-

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tanzo, 1991) the fourth hypothesis predicted that, across cultures, womenwould have higher accuracy, but lower rated confidence, on the IPT. Fi-nally, because we recruited Japanese participants with varying ability inspoken English, we hypothesized that those with greater English profi-ciency would have higher accuracy scores and greater rated confidence intheir judgments.

Method

Design and Participants

The study employed a 2 (Japanese and American participants) � 2(Audiovisual vs. Visual only presentation) � 2 (Sex of participant) factorialdesign. A total of 344 students participated in the study. The 229 Japaneseparticipants (116 females and 113 males) were recruited from several dif-ferent junior colleges and universities in Okayama, Hiroshima, and Shi-mane in Japan. After eight participants were dropped due to incompleteresponses, the remaining 221 Japanese participants included 113 femalesand 108 males. An attempt was made to recruit approximately equal num-bers of Japanese participants with low-level ability and moderate-levelability in conversational English, as determined by their instructors. TheJapanese participants were tested in their classrooms in groups rangingfrom 10–20 in number. The American participants (75 females and 40males) were recruited from psychology classes at a midwestern urban uni-versity. Participants were run in small groups of seven or fewer in numberand received extra credit points in their courses for being in the experi-ment.

Procedure

General. Participants were told that they would be seeing a videotapecontaining 15 different, brief scenes and their task was to make judgmentsabout the people in the scenes. No additional description was given in theAudiovisual condition. In the Visual-Only condition, participants were toldthat they were going to see the video without sound. The Japanese partici-pants were instructed in Japanese and told that the people in the videowould be speaking English.

Interpersonal perception task. The IPT-15 is a 20-minute videotapethat shows 15 naturalistic scenes, with one to four individuals in eachscene. The scenes last from 28 to 122 seconds in length and, for each

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scene, there is an objectively correct answer to a question about the peo-ple in the scene. For example, one scene shows a short interaction be-tween two people and then the viewer is asked to judge which of the twopeople is the boss. The scenes were edited so that they contained no ob-vious verbal information for answering the questions about the scenes. Fivedifferent types of scenes are sampled, including kinship, intimacy, decep-tion, competition, and status, with three scenes in each area. Participantschose from two or three alternatives for each scene on a standardized an-swer sheet. For the Japanese participants, the answer sheet was in Japa-nese.

In an earlier study on over 240 American participants, Cronbach’s al-pha for the IPT-15 was only .14 (Patterson, Foster, & Bellmer, 2001). Forthe Japanese sample in the present study, Cronbach’s alpha was only .17.Nevertheless, Hall and Carter (1999) noted that, in spite of the low internalconsistency on the IPT, there is good evidence for the validity of the IPT(e.g., Ambady, Hallahan, & Rosenthal, 1995; Costanzo & Archer, 1989;Patterson & Stockbridge, 1998). In fact, Costanzo and Archer (1989) sug-gested that the internal consistency was relatively low because the IPTsampled a diverse range of scenes.

Post-IPT measures. After completing the IPT, participants were askedto respond on a separate form in their native language to the followingitems: (1) how many questions out of 15 do you think you answered cor-rectly?; (2) rated difficulty of the IPT; and (3) rated overall confidence intheir answers.1 The last two ratings were all completed on 11-point ratingscales. Japanese participants also rated their proficiency in spoken Englishon an 11-point rating scale as a manipulation check on their instructors’classification of English proficiency. In fact, participants classified as havingmoderate proficiency (M � 4.86) rated their English ability as significantlygreater (t (219) � 10.29, p � .001, r � .57) than did participants classi-fied as having low proficiency (M � 2.40). After all of the ratings werecompleted, the Japanese participants were given an opportunity to writedown any additional reactions to the study.

Results

Japanese-American Comparisons

IPT accuracy. The average number correct for all participants was 8.49items, which was significantly higher than the chance level of 6.33 items, t(335 � 19.70, p � .001). A 2 (Culture) � 2 (Presentation Modality) � 2

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(Sex of Participant) factorial ANOVA was computed on participants’ scoreson the IPT. A significant effect of Culture, F (1, 328) � 16.65, p � .001,r � .22, provided support for the first hypothesis, with Americans (M �9.11) scoring higher than Japanese (M � 8.17). The effect of PresentationModality was not statistically significant, F (1, 328) � 2.63, p � .15, r �.09 and although the difference between the Audiovisual (M � 8.45) andVisual-Only (M � 8.54) conditions was small, it was opposite the pre-dicted direction.

Next, the Culture � Presentation Modality effect, F (1, 328) � 21.51,p � .001, r � .25, did qualify the main effect of Culture, but not in themanner predicted by the third hypothesis. Specifically, tests of simple maineffects indicated that American participants were significantly more accu-rate in the Audiovisual condition (M � 9.78) than in the Visual-Only con-dition (M � 8.52, t (113) � 3.41, p � .001, whereas Japanese partici-pants were significantly less accurate in the Audiovisual condition (M �7.84) than in the Visual-Only condition (M � 8.54), t (219) � �2.77,p � .01). Thus, contrary to our expectation, the Japanese participants weremore accurate in the Visual-Only condition than in the Audiovisual condi-tion. Support for the first part of the fourth hypothesis was manifested in asignificant effect of Sex of Participant, F (1, 328) � 6.00, p � .02, r � .13,with women (M � 8.84) scoring higher than men (M � 8.05). There wereno other main or interaction effects of any of the factors on IPT accuracy.

Confidence measures. First, correlations were computed between thepost-IPT measures. The estimated number correct correlated positively withrated confidence, r (330) � .70, and negatively with the rated difficulty ofthe IPT, r (330) � �.49. Rated confidence correlated negatively with rateddifficulty, r (334) � �.51. Because these ratings were moderately tohighly correlated, they were combined to form a single composite measureof confidence. Specifically, the individual measures were standardized andthe mean of the three Z scores, with the difficulty rating negativelyweighted, formed the new composite measure of confidence, with coeffi-cient alpha � .79. A 2 (Culture) � 2 (Presentation Modality) � 2 (Sex ofParticipant) ANOVA was computed on the confidence composite. First,there was a significant effect of Culture, F (1, 324) � 68.56, p � .001,r � . 42, with Americans (M � .48) more confident than the Japanese(M � �.24). Next, there was a significant effect of Sex of Participant, F (1,324) � 7.57, p � .01, r � .15, with men (M � .07) more confident thanwomen (M � �.06). Finally, there was a Presentation Modality � Cultureinteraction effect, F (1, 324) � 11.12 p � .001, r � .18. Specifically, onthe confidence composite, American (M � .57) superiority over the Japa-

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nese (M � �.43) in the Audiovisual condition was greater than the Ameri-can (M � .39) superiority over the Japanese (M � �.03) in the Visual-Only condition.

Accuracy-confidence correlations. In the combined sample, accuracywas significantly correlated only with the estimated number correct (r �.16) and with rated difficulty (r � �.17). Table 1 shows the correlationsbetween the number correct on the IPT and the various individual andcomposite confidence measures. Although the correlations were, in gen-eral, relatively small, a number of them were significant. First, the Japaneseparticipants (r � .15) were marginally better at predicting their scores(z � 1.63, p � .06) than the American participants (r � �.05) were.Next, when the accuracy-confidence correlations were computed sep-arately for male and female participants, the general pattern showed thatestimated number correct, rated difficulty, and the composite confidencemeasures correlated significantly with accuracy. Finally, a comparison be-tween the Audiovisual and Visual-Only conditions, showed that, in three ofthe four confidence measures, accuracy-confidence correlations were sig-nificant for participants in the Audiovisual condition, but not in the Visual-Only condition. The pattern of correlations between the two conditionswas consistent, with some of the differences between the Audiovisual andVisual-Only accuracy-confidence correlations approaching significance(.91 � � z � � 1.63, .37 � p’s � .06). Thus, confidence was a somewhatbetter predictor of accuracy in the Audiovisual condition in the Visual-Only condition.

Japanese Sample

IPT accuracy. Because the Japanese participants were classified interms of their facility with spoken English, we also analyzed their dataseparately to determine whether their overall pattern of results was moder-ated by English proficiency. A 2 (Low vs. Moderate English Proficiency)� 2 (Sex of Participant) � 2 (Presentation Modality) ANOVA on IPT accu-racy showed a significant main effect of English Proficiency F (1, 213) �21.94, p � .001, r � .31). Thus, moderate proficiency participants(M � 8.71) were more accurate than low proficiency participants (M �7.59), providing support for the final hypothesis. A significant effect of Sexof Participant (F (1, 213) � 10.89, p � .001, r � .22) was reflected inwomen (M � 8.55) scoring better than men (M � 7.76), a difference thatwas also present in the combined analysis. There was also a significanteffect of Presentation Modality (F (1, 213) � 7.48, p � .01, r � .18), with

TABLE 1

Correlations Between Accuracy and Confidence Measures as Function of Condition

Japanese American Males Females Audiovisual Visual(N � 221) (N � 115) (N � 148) (N � 184) (N � 172) (N � 164)

Estimated � correct .15* �.05 .18* .17* .23** .07Confidence .03 �.06 .09 .09 .10 .00Difficulty �.10 �.07 �.21** �.14 �.24** �.06Confidence composite .11 �.01 .19* .17* .23** .06

*p � .05; **p � .01.

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participants in the Visual Only condition (M � 8.48) having more correctthan participants in the Audiovisual condition (M � 7.83). The Presenta-tion Modality effect for the Japanese participants was, of course, one half ofthe Culture � Presentation Modality interaction for the combined sample.That is, the American participants had more correct in the Audiovisualcondition than in the Visual-Only condition, but the opposite pattern wasfound for the Japanese participants.

There was also an unexpected English Ability � Sex of Participant �Presentation Modality interaction effect (F (1, 213) � 4.20, p � .05,r � .14). In general, the excess of female superiority found in the moderatecompared to the low English proficiency participants in the Visual-Onlycondition was offset by a decrease in the female superiority found in themoderate compared to the low proficiency participants in the Audiovisualcondition. The cell means are shown in Table 2.

Confidence measures. For the Japanese sample, the same compositemeasure of confidence, based on the mean of the standardized scores ofthe estimated number correct, rated confidence, and rated difficulty (nega-tively weighted) were used in the analysis. A 2 (English Proficiency) � 2(Presentation Modality) � 2 (Sex of Participant) ANOVA was computed onthe composite scores. First, there was a significant effect of Sex of Partici-pant, F (1, 213) � 6.10, p � .02, r � .17, with men (M � .10) more con-fident than women (M � �.09). Next, there was also a significant effect ofPresentation Modality, F (1, 213) � 15.20, p � .001, r � .26, with ahigher level of confidence in the Visual-Only condition (M � .22) than inthe Audiovisual condition (M � �.19). There was also a Sex of Partici-pant � Presentation Modality interaction, F (1, 213) � 5.17, p � .05,

TABLE 2

Mean IPT Accuracy of Japanese Participants as a Function of EnglishProficiency, Sex, and Presentation Modality

Low Englishproficiency

Moderate Englishproficiency

Modality Male Female Male Female

Visual only 8.04 8.05 8.52 9.30Audiovisual 6.26 8.03 8.21 8.80Combined 7.15 8.04 8.33 9.09

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r � .15. In particular, the superiority of males’ confidence in the Visual-Only (M � .46) condition compared to the Audiovisual (M � �.19) con-dition was greater than the superiority of females’ confidence in the Visual-Only (M � .01) condition compared to the Audiovisual (M � �.19).There was also an unexpected English Proficiency � Presentation Modal-ity � Sex of Participant interaction, F (1, 213) � 5.72, p � . 05, r � .16).

Finally, in the open-ended comments that followed the completion ofthe ratings, approximately 25% of the Japanese participants in the Audio-visual condition mentioned the difficulty of understanding the spoken En-glish in the IPT scenes. Reference was also made to the spoken Englishbeing too fast or to frustration in trying to understand the speakers.

Discussion

The results of the present experiment provided mixed support for the pre-dicted effects of culture, presentation modality, and sex of participant onaccuracy and confidence in social judgments. First, the significant maineffect of Culture on IPT accuracy was clearly qualified by a Culture � Pre-sentation Modality interaction effect. Specifically, although American andJapanese participants had comparable scores in the Visual-Only condition,Americans’ scores increased and Japanese’ scores decreased with the addi-tion of sound in the Audiovisual condition. The main effect of Culture onthe confidence measures was also qualified by a Culture � PresentationModality interaction effect. Although American participants were signifi-cantly more confident than the Japanese participants, this difference wasmuch larger in the Audiovisual condition than in the Visual-Only condi-tion. Next, consistent with the hypothesis on sex differences, women weresignificantly more accurate on the IPT than men were, but were less confi-dent about their answers than the men were. The separate analysis of theJapanese sample provided an opportunity to examine the effect of facilitywith spoken English on IPT accuracy and confidence. In general, partici-pants with moderate English proficiency were more accurate on the IPT.Although Japanese participants were more confident in the Visual-Onlycondition than in the Audiovisual condition, there were no main or inter-action effects of English proficiency on confidence.

Culture and Presentation Modality

The most surprising result of the present study was the specific patternof the Culture � Presentation Modality effect on IPT accuracy. Our basic

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predictions were that (1) American participants would be more accuratethan the Japanese; (2) accuracy would be higher for both Americans andJapanese in the Audiovisual condition than in the Visual-Only condition;but (3) the difference between the Americans and the Japanese would begreater in the Audiovisual condition. The rationale underlying these predic-tions was that American participants should have an advantage becausethey were making judgments about other Americans in the IPT scenes andtheir obvious facility with spoken English would be an added factor in theAudiovisual condition. Nevertheless, we also expected the Japanese partic-ipants to improve in the Audiovisual condition because, even if they didnot understand the spoken English, they could still benefit from the vocalcues.

In fact, Japanese and American participants had virtually identical av-erage scores on the IPT in the Visual-Only condition, more than two itemsabove a chance level of accuracy. This was the case even though the fif-teen IPT scenes included Americans either living in California or going tocollege there. Perhaps the most obvious explanation for the equivalentscores in the Visual-Only condition is that there are behavior patterns pre-sent in the IPT that transcend the broad cultural differences between theU.S. and Japan. Of course, most Japanese participants also have exposureto American social behavior through television. Still another explanationmight be that, because Japan is a high-context culture in which informationis commonly communicated indirectly, the Japanese are generally moresensitive to nonverbal cues than Americans are (Hall, 1976). Thus, anydisadvantage of the Japanese in not having as much familiarity with Ameri-can patterns might be offset by their greater habitual sensitivity to nonver-bal messages.

The other half of the Culture � Presentation Modality effect was alsosurprising. Although American participants scored higher in the Audio-visual than in the Visual-Only condition, consistent with previous studies(Patterson & Stockbridge, 1998; Smith, Archer, & Costanzo, 1991), Japa-nese participants scored lower in the Audiovisual condition than in theVisual-Only condition. Furthermore, the Japanese participants in the Au-diovisual condition were less confident than those in the Visual-Only con-dition. In addition, a number of participants in the Audiovisual conditionreported difficulty and frustration in trying to follow the spoken English. Itis likely that this experience precipitated cognitive overload and decreasedaccuracy of judgments (Gilbert, Pelham, & Krull, 1988). To the extent thatsocial judgments, especially those based on nonverbal behavior, are rela-tively automatic and outside of awareness (Bargh, 1994, Brewer, 1988),then it is unlikely that the negative effect of cognitive overload is due to an

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inability to weigh the information and draw an appropriate conclusion.Rather, the cognitive overload may have prevented the adequate register-ing of the incoming information. In other words, if these social judgmentsare primarily automatic, then errors are more likely to occur when atten-tion, not reflection, is interrupted. In hindsight, it is clear that simply pre-senting the English audio track to Japanese participants was not equivalentto adding vocal or paralinguistic cues to the Visual-Only condition. Analternative might be to employ a content filtering device that makes speechunintelligible by eliminating a range of vocal frequencies in the audiotrack.

A final issue that merits mention is the apparent difference betweenthe Japanese and American participants’ ability to estimate their judgmentaccuracy. Specifically, the difference between the accuracy-estimatedscore correlations for the Japanese (r � .16, p � .05) and Americans(r � �.05) approached significance. That is, across participants, the Japa-nese showed some sensitivity in their estimates of accuracy, whereas theAmericans did not.

Sex Differences

The hypothesized sex differences in accuracy and confidence weresupported in the combined analysis on both cultures. In general, womenwere more accurate on the IPT, but showed less confidence in their judg-ments than men did, consistent with the results of earlier studies on the IPT(Costanzo & Archer, 1989; Smith, Archer, & Costanzo, 1991). In fact, thereis an extensive literature documenting women’s greater nonverbal sensi-tivity in making judgments of others. Hall (1985) reported that, in over80% of the 120 studies she reviewed, women were more accurate thanmen in their judgments.

What might account for women’s greater sensitivity in judging others?One explanation has been described as the “oppression hypothesis.” Thatis, because women in most societies have traditionally had less power thanmen, it is adaptive to develop skill in judging other people. Another possi-bility is that women are more likely than men to possess traits of empathyor femininity that, in turn, facilitate more accurate judgments. Hall (1985)concluded, however, that there was little research supporting either ofthese explanations. An alternative explanation, grounded in biology, isthat, over the course of evolution, natural selection has favored the off-spring of more sensitive women. In other words, mothers who were moresensitive in reading subtle changes in their children were more likely tohave offspring who survived, later reproduced, and passed on a similar

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tendency. Of course, even if there is an evolutionary basis for women’sgreater accuracy in social judgments, social or cultural expectancies canalso reinforce this difference. Thus, young girls in many cultures are typ-ically taught to be more considerate, cooperative, and sensitive than youngboys are.

Japanese women, like American women, estimated that they had feweritems correct and reported less confidence, even though they actually hadhigher scores than men. Nevertheless, a study by Iizuka (1998) found thatJapanese women judged themselves better at accurately perceiving othersthan Japanese men did. In the Iizuka (1998) study, participants rated forty-six items dealing with specific examples (e.g., I can usually tell whensomeone is hostile from the tone of the person’s voice) on a seven-pointscale of agreement-disagreement. Although Iizuka did not measure the ac-curacy of actual social judgments, his results suggest that Japanese women(and men) correctly identify their relative skill in social perception. How dowe resolve this apparent inconsistency between Iizuka’s results and thepattern of women’s lower confidence in the present study? It is possiblethat asking participants to make their own performance evaluation aftercompleting the IPT is very different from asking them about their typicalability in making social judgments. In the former case, females may be lesslikely to take credit for a success than males are because modesty aboutone’s performance is consistent with a female sex role. On the other hand,when females report (as in the Iizuka study) that they are sensitive in read-ing other people, this is also consistent with sex role expectancies.

Conclusions

The present study demonstrated that even a culturally specific test of inter-personal sensitivity, like the IPT, can be usefully employed across cultures.It was not surprising that Americans were generally more accurate than theJapanese on the IPT, but it was particularly interesting that their scoreswere almost exactly equal in the Visual-Only condition. In contrast, in theAudiovisual condition, the English audio track was apparently confusing ordistracting for the Japanese participants, especially for those with less facil-ity in spoken English. Although Japanese and American females were moreaccurate than their male counterparts, they reported less confidence intheir answers than males did.

Because the results reported here are based on convenience samplestested in the two cultures, it is possible, of course, that other characteristicsof the samples might contribute to these differences. Nevertheless, there

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are a number of different questions that might be pursued at this point. Forexample, would Japanese who are highly skilled in spoken English performbetter in the Audiovisual condition than the Japanese participants in thepresent study? If the vocal channel could be isolated from the audio track,would the presence of speech characteristics such as intonation, pace, andpause improve performance relative to the Visual-Only condition? Howwould people from other non-English speaking cultures score on the IPT,especially in the Visual-Only condition? Would those from high-contextcultures be more accurate on the IPT than those from low-context cultures?The use of videotaped samples of real-life interactions provides a moreecologically valid means of studying cultural differences in social judg-ments than simply relying on descriptive vignettes or still photographs offacial expressions. Eventually, videotape tests similar to the IPT could bedeveloped in countries outside of the United States to broaden the meansby which we examine similarities and differences across culture in the ac-curacy of social judgments.

Note

1. The post-IPT measures differed slightly between the Japanese and American participants.Japanese participants also rated how much they thought about their answers and howgood they were at judging other people. American participants also rated how much effortthey put into the task. Because only one significant effect was found on preliminary within-culture analyses across these three ratings, these measures were not included in the finalanalyses.

References

Ambady, N., Bernieri, F. J., & Richeson, J. A. (2000). Towards a histology of social behavior:Judgmental accuracy from thin slices of the behavioral stream. In M. P. Zanna (Ed.),Advances in experimental social psychology (pp. 201–272). Boston: Academic Press.

Ambady, N., Hallahan, M., & Rosenthal, R. (1995) On judging and being judged accurately inzero acquaintance situations. Journal of Personality and Social Psychology, 69, 518–529.

Ambady, N., & Rosenthal, R. (1992). Thin slices of behavior as predictors of interpersonalconsequences: A meta-analysis. Psychological Bulletin, 111, 256–274.

Bargh, J. A. (1994). The four horsemen of automaticity: Awareness, intention, efficiency, andcontrol in social cognition. In R. S. Wyer, Jr. & T. K. Srull (Eds.), Handbook of socialcognition (Vol. 1, pp. 1–40). New York: Erlbaum.

Bargh, J. A., & Chartrand, T. L. (1999). The unbearable automaticity of being. American Psy-chologist, 54, 462–479.

Bernieri, F., & Gillis, J. S.(1995). The judgment of rapport: A cross-cultural comparison be-tween Americans and Greeks. Journal of Nonverbal Behavior, 19, 115–130.

Bond, C. F., Jr., Omar, A., Mahmoud, A., & Bonser, R. N. (1990). Lie detection across culture.Journal of Nonverbal Behavior, 14, 189–204.

174

JOURNAL OF NONVERBAL BEHAVIOR

Brewer, M. B. (1988). A dual process model of impression formation. In T. K. Srull & R. S.Wyer, Jr. (Eds.), Advances in social cognition (Vol. 1, pp. 1–36). Hillsdale, NJ: Erlbaum.

Costanzo, M., & Archer, D. (1989). Interpreting the expressive behavior of others: The inter-personal perception task. Journal of Nonverbal Behavior, 13, 225–235.

Costanzo, M., & Archer, D. (Producers). (1993). Interpersonal perception task-15 [videotape].(Available from the University of California Extension Center for Media and IndependentLearning, 2000 Center Street, Berkeley, CA 94704).

Ekman, P. (1994). Strong evidence for universals in facial expressions: A reply to Russell’smistaken critique. Psychological Bulletin, 115, 268–287.

Gilbert, D. T., Pelham, B. W., & Krull, D. S. (1988). On cognitive busyness: When personperceivers meet persons perceived. Journal of Personality and Social Psychology, 54,733–740.

Hall, E. T. (1976). Beyond culture. Garden City, NY: Anchor Books.Hall, J. A. (1985). Male and female nonverbal behavior. In A. W. Siegman & S. Feldstein

(Eds.), Multichannel integrations of nonverbal behavior (pp. 195–225). Hillsdale, NJ:Erlbaum.

Hall, J. A., & Carter, J. D. (1999). Gender-accuracy stereotype as an individual difference.Journal of Personality and Social Psychology, 77, 350–359.

Heider, F. (1958). The psychology of interpersonal relations. New York:Wiley.Iizuka, Y. (1998). Preliminary analysis of individual differences of the perceived encoding and

decoding abilities (1). Bulletin of Shimane Nursing College, 3, 69–76.Izard, C. E. (1994). Innate and universal facial expressions: Evidence from developmental and

cross-cultural research. Psychological Bulletin, 115, 288–299.Jones, E. E., & Davis, K E. (1965). From acts to dispositions: The attribution process in person

perception. In L. Berkowitz (Ed.), Advances in experimental social psychology (Vol. 2,pp. 219–266). New York: Academic Press.

Patterson, M. L., Foster, J. L., & Bellmer, C. D. (2001). Another look at accuracy and confi-dence in social judgments. Journal of Nonverbal Behavior, 25, 207–219.

Patterson, M. L., & Stockbridge, E. (1998). Effects of cognitive demand and judgment strategyon person perception accuracy. Journal of Nonverbal Behavior, 22, 253–263.

Rosenthal, R., Hall, J. A., Archer, D., DiMatteo, M. R., & Rogers, P. L. (1979). The PONS testmanual: Profile of nonverbal sensitivity. New York: Irvington Publishers.

Russell, J. A. (1994). Is there a universal recognition of emotion from facial expression? Areview of the cross-cultural studies. Psychological Bulletin, 115, 102–141.

Russell, J. A. (1995). Facial expressions of emotion: What lies beyond minimal universality?Psychological Bulletin, 118, 379–391.

Smith, E. R. (1990). Content and process specificity in the efects of prior experience. In T. K.Srull & R. S. Wyer, Jr. (Eds.), Advances in social cognition (Vol. 3, pp. 1–59). Hillsdale,NJ: Erlbaum.

Smith, H. J., Archer, D., & Costanzo, M. (1991). “Just a hunch”: Accuracy and awareness inperson perception. Journal of Nonverbal Behavior, 15, 3–18.

Zebrowitz, L. A., & Collins, M. A. (1997). Accurate social perception at zero acquaintance:The affordances of a Gibsonian approach. Personality and Social Psychology Review, 1,204–233.