Explanations for Visual Cue Primacy in Judgments of ... - APA PsycNET

Journal of Personality and Social Psychology 1989, Vol. 56, No. 4, 555-564

Copyright 1989 by the American Psychological Association, Inc. 0022-3514/89/S00.75

Explanations for Visual Cue Primacy in Judgments of Honesty and Deceit James B. Stiff, Gerald R. Miller, and Carra Sleight Michigan State University Paul Mongeau Miami University

Rick Garlick Spring Arbor College

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Randall Rogan Michigan State University Examined the validity of the distraction hypothesis (Maier & Thurber, 1968). Ss were undergraduate students who watched a videotaped interview and rated the veracity of an actress who played the role of a college student. Study 1 disconfirmed the distraction hypothesis. Ss relied on nonverbal cues to make judgments of veracity, but the presence of nonverbal cues did not distract Ss from processing verbal content. Study 2 tested an alternate explanation, the situational familiarity hypothesis. Study 2 found that judgments in familiar situations were influenced primarily by verbal content cues, whereas those in unfamiliar situations were influenced by both verbal and nonverbal cues. Findings indicate that situational factors influence information processing and affect the relative importance of verbal and nonverbal cues in judgments of veracity. Generalizability of prior deception research is questioned.

Research on deceptive communication has followed two paths: One traveled by researchers seeking to isolate verbal and nonverbal correlates of deception (for reviews, see Zuckerman, DePaulo, & Rosenthal, 1981; Zuckerman & Driver, 1985); the second by researchers interested in the lie detection abilities of humans (for reviews, see Kalbfleisch, 1985; Kraut, 1980). Although conceptually unique, the two issues are empirically related. Unfortunately, pursuit of one set of issues has typically relegated the other to the status of "the road not taken." Because explanations for the primacy of visual cues in judgments of deception are the focus of this article, we see these two issues as necessarily interrelated. Investigation of one without concern for the other offers a limited view of the deception process.

of verbal behavior in deceptive messages (Cody, Marston, & Foster, 1984; Stiff & Miller, 1986). Researchers have been less concerned with identifying the relation between cues related to actual truth and deception and those related to judgments of honesty and deceit. Four studies reported data on both sets of cues (Kraut, 1978; Maier & Janzen, 1967; Riggio & Friedman, 1983; Stiff & Miller, 1986). In all four studies, cues related to actual truth and deception differed from those related to judgments of honesty and deceit. Comparing results from all studies (including unpublished studies and those that investigated these issues separately), Zuckerman et al. (1981-) reported only three cues (speech errors, speech hesitation, and pitch) associated with both judgments of deception and actual deception. This finding suggests that many cues individuals rely on for judgments of veracity are unrelated to cues associated with actual veracity. Given that people typically have difficulty detecting deception at better than chance levels (Kalbfleisch, 1985; Kraut, 1980), these meta-analytic results underscore one possible direction for future research. Specifically, explanations for reliance on cues that are unrelated to actual truth and deception may provide a theoretical foundation for understanding errors in deception detection. In the studies described in this article, we investigated two explanations for the primacy of nonverbal cues. In Study 1, we tested the distraction hypothesis; in Study 2 we tested an alternate explanation, the situational familiarity hypothesis.

Verbal and Nonverbal Correlates Considerable research has sought to isolate the nonverbal correlates of deception (Zuckerman et al., 1981; Zuckerman & Driver, 1985). Although these studies have reported numerous visual and auditory correlates of deception, the meta-analytic reviews of Zuckerman and his colleagues produced only a handful of visual and vocal cues that consistently relate to deception across studies. By comparison, research on verbal correlates of deception has been limited. Knapp, Hart, and Dennis (1974) and Kraut (1978) pioneered in this area; however, investigators have only recently focused on isolating the causal determinants

Distraction Hypothesis A number of researchers have relied on the distraction hypothesis as an explanation of why people use certain cues when making judgments of veracity (Bauchner, Brandt, & Miller,

Correspondence concerning this article should be addressed to James B. Stiff, Department of Communication, Michigan State University, East Lansing, Michigan 48824-1212.

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1977; Hocking, Bauchner, Kaminski, & Miller, 1979; Maier & Thurber, 1968). This hypothesis is familiar to persuasion researchers. Although several theoretical interpretations have been offered to explain the effects of distracting stimuli, one seems particularly relevant to deception researchers. Specifically, the message comprehension explanation holds that the presence of distractors decreases message comprehension, which in turn limits the persuasive effects of message content and inhibits attitude change (Insko, Turnbull, & Yandell, 1974; Zimbardo, Snyder, Thomas, Gold, & Gurwitz, 1970). In deceptive interactions, deceivers attempt to persuade others that deceptive messages are truthful. Nonverbal cues have been hypothesized to "distract" individuals from focusing on the verbal content of deceptive messages, thus making it more difficult to identify the characteristics of verbal content associated with honesty and deceit (Bauchner et al, 1977; Maier & Thurber, 1968). Maier and Thurber (1968) first used distraction as a post hoc explanation for their counterintuitive findings dealing with deception detection in interview situations. People who watched truthful and deceptive role-play interviews were significantly less accurate in detecting deception (58%) than were people who listened to recordings (77%) and people who read transcripts (77%). Maier and Thurber argued that the visual cues available in the live role plays may have "distracted" raters from attending to more useful vocal and verbal information. Two additional studies have a bearing on the distraction hypothesis. Hocking et al. (1979) reported findings consistent with those of Maier and Thurber (1968). Although Bauchner et al. (1977) reported findings that are somewhat inconsistent with the other two studies, they used procedural differences as one explanation for these differences. Unfortunately, flaws in the manipulation of verbal, vocal, and visual information in these studies have prevented a fair test of the distraction hypothesis. For example, Maier and Thurber's (1968) manipulation of cue exposure confounded type of cue information with mode of cue presentation: People exposed to verbal, vocal, and visual cues saw a live presentation; those exposed to verbal and vocal cues heard an audio presentation; and those exposed only to verbal cues read a transcript. This confound assumes added importance when considering the effects of communication modality on counterarguing (Wright, 1981) and the salience of communicator-related information (Chaiken & Eagly, 1983). These modality effects are consistent with general vividness effects (Nisbett & Ross, 1980; Taylor & Thompson, 1982) and the influence of vivid information on perceptions of persuasiveness (Collins, Taylor, Wood, & Thompson, 1988). Thus, a convincing test of the distraction hypothesis requires manipulation of the type and amount of verbal and nonverbal information without varying the mode of message presentation. Two features of the procedures used in Study 1 permitted an adequate test of the distraction hypothesis: First, visual, vocal, and verbal cue information was varied systematically while holding the mode of message presentation constant. Second, besides measuring the effect of these cue combinations on judgments of truth and deception, we assessed the extent to which message recipients could recognize features of verbal, vocal, and visual cue information.

Study 1 Predictions When applied in deceptive situations, the distraction hypothesis posits that visual information inhibits processing of verbal content. Because visual cues are distracting, detectors will rely on these cues when making judgments of deception and will be unable to recognize differences in verbal content. Thus, support for the distraction hypothesis must satisfy two criteria: First, judgments of honesty and deceit should be dominated by visual cue information and should be relatively uninfluenced by verbal cue information. Specifically, observers exposed to messages containing deceptive visual information should judge the target to be significantly more deceptive than should those exposed to truthful visual information, regardless of the nature of the verbal content. Second, observers exposed to visual cues should be unable to accurately identify the characteristics of verbal content readily detectable by participants who read transcripts of the interview. One can also hypothesize that people exposed to deceptive visual conditions will be more distracted than those exposed to truthful visual conditions. If this occurs, one would anticipate a main effect for visual information on judgments of verbal content. The deception literature yields various predictions about the effects of distraction on perceptions of vocal cue information. Although we offer no specific hypotheses in this study, we thought investigation of vocal information was potentially useful, and therefore included vocal cue manipulations in the study.

Method Subjects Subjects were 271 undergraduate student volunteers enrolled in communication courses at a large midwestern university who received extra credit for participation. They were told that the experiment would require them to watch videotaped interviews.

Design The design was a four-factor independent-groups design. We crossed two levels of each of the following variables with one another: message content (truthful or deceptive), visual cue information (truthful or deceptive), vocal cue information (truthful or deceptive), and sex of the actor (male or female). We assigned 10 subjects to each of the 16 cells in the design. In addition, we assigned 20 to one of two verbal control conditions. In one verbal control condition, participants read the truthful verbal transcript; in the second, they read the deceptive verbal transcript. We assigned another 71 participants to one of the visual control conditions in which they watched video-only presentations of the actors' truthful or deceptive visual cues.

Stimulus Materials We designed stimulus materials to approximate the behavior of truthtellers and liars. One male and one female actor were paid to play the role of a student being questioned by a professor about a recent examination cheating incident. Each "interview" was approximately 3 min long and contained four question-and-answer sequences. Verbal manipulation:,' 'Two studies of the general characteristics of

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DECEPTION DETECTION truthful and deceptive verbal messages (Kraut, 1978; Stiff & Miller, 1986) have revealed that the content of truthful messages is rated as more concise, plausible, and consistent than that of deceptive messages. In the present study, we manipulated verbal content by creating truthful and deceptive transcripts reflecting these characteristics. In half the interviews, the actors responded verbatim using a truthful verbal script; in the other half, they used a deceptive verbal script. A pretest using 30 raters indicated that the truthful verbal script was rated as more concise, clear, plausible, and consistent than the deceptive verbal script. In addition, the truthful verbal script was rated as significantly more truthful than the deceptive verbal script, /11, 28) = 16.81, p .05, r = .03. There were also no significant interactions among the three types of cue information and perceptions of truth and deception. Evaluations of Verbal, Vocal, and Visual Cues In addition to rating deceptiveness, subjects evaluated the following verbal and nonverbal cues of the actors: the verbal content of the message, the actors' eye behavior, the actors' voices, and the actors' overall behavior. Evaluations of verbal content. Evaluation of verbal message content is a critical component of the test of the distraction hypothesis. If the hypothesis is correct, observers exposed to visual cues (all experimental conditions) should not be able to identify characteristics of verbal content accurately. The data in Table 3 indicate that observers exposed to visual and verbal cues judged the truthful verbal message as significantly more plausible, consistent, coherent, and specific than the deceptive verbal message, F(l, 146) = 23.45, p < .01, r = .35. In short, the presence of visual information did not prevent observers from accurately evaluating verbal content. Although the effect of the verbal content manipulation on believability of verbal content was smaller among observers (r = .35) than among control group participants who read a transcript of the interview (r = .67), the effect for observers exposed to both verbal and visual cues was quite substantial and significantly different from zero. It is possible that the presence of visual cues produced a smaller effect size for the verbal content manipulation among observers in the experimental conditions; however, it is also possible that modality effects may account for the difference between experimental and control group ratings of verbal content. Taylor and Thompson noted that "those who have printed messages have the opportunity to go back to sections that were unclear, whereas the same opportunity is not afforded by T.V. or orally presented messages" (1982, p. 165). Nevertheless, the observers in the experimental conditions exposed to visual cues were able to identify characteristics of verbal content. We observed a similar effect for the vocal cue manipulation. The content of messages in the deceptive vocal conditions was evaluated as more deceptive (regardless of actual message content) than was the content of messages in the truthful vocal conditions, F( 1,146) = 18.30, p< .01, r = .31. Apparently, observers had difficulty separating verbal cues from vocal cues when making judgments of verbal content. In addition, the main effect for the visual cue manipulation and the interaction effects were trivial in size and nonsignificant. The nonsignificant main

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DECEPTION DETECTION

Table 2 Average Ratings of Truth and Deception Truthful verbal Truthful vocal

Deceptive verbal

Deceptive vocal

Truthful vocal

Deceptive vocal

Condition

Rating

SD

Rating

SD

Rating

SD

Rating

SD

Deceptive visual Truthful visual

5.90 4.05

0.72 1.82

5.95 4.75

0.69 1.25

5.50 4.35

1.70 1.66

6.05 5.15

0.60 1.06


Note,N= 160.1 = Truthful, 1 = Deceptive.

effect for the visual cue manipulation suggests that the relative amount of visual activity is unrelated to observer judgments of verbal content. In summary, these results reveal that perceptions of verbal content were affected by the verbal content and vocal cue manipulations. Neither the presence of visual cues nor the amount of visual cue activity (truthful vs. deceptive visual manipulations) influenced ratings of verbal content. Evaluations of eye behavior. Analysis of the eye behavior evaluations indicates an expected large main effect for the visual cue manipulation, F[l, 152) = 91.55,p < .01, r = .60. Subjects in the truthful visual information conditions rated the actors' eye behavior as more believable (direct, secure, and certain) than did those in the deceptive visual cue information conditions. The vocal cue manipulation also had a small but significant effect on judgments of eye behavior, F( 1, 152) = 5.21, p < .05,r=.14. Evaluations of vocal behavior. The vocal information manipulation significantly influenced subject evaluations of the believability of the vocal cues, F ( l , 151) = 27.06,/> < .01, r = .35. Subjects in the truthful vocal conditions rated the actors' vocal behavior as more direct, certain, and sure than did those in the deceptive vocal conditions. Strangely, however, the visual information manipulation exerted a stronger effect on subject evaluations of vocal behavior, F ( l , 151) = 35.09, p < .01, r = .41, than did the vocal cue manipulation. In this case, subjects in the truthful visual conditions rated the actors' vocal behavior as more consistent, certain, and sure than did those in the deceptive visual conditions. This counterintuitive finding suggests that global impressions may arise primarily from visual cue information and that these global impressions influence the specific evaluations of vocal behavior.

Evaluations of overall behavior. The visual cue information manipulation strongly affected subject evaluations of the believability of actors' overall behavior, F(l, 147) = 93.28, p < .01, r = 61. Individuals relied heavily on visual cues when making judgments about overall behavior. Vocal cue information had a significant but much smaller effect on subject evaluations of overall behavior, F( 1,147) = 9.56, p< .01, r = . 19. These results also -support the hypothesis that visual cues strongly influence global impressions of actors' nonverbal behaviors. Discussion Although Study 1 replicated previous research demonstrating the primacy of nonverbal cues in judgments of honesty and deceit, the distraction hypothesis cannot account for these results. Even though the finding that observers relied primarily on visual cues to make their judgments is consistent with the distraction hypothesis, a critical feature of the study was the effect of visual, vocal, and verbal cues on judgments of verbal behavior. On this point, the data are clear: Observers exposed to visual behavior were able to distinguish between truthful and deceptive verbal content. This finding is incompatible with the distraction explanation, which specifies that the presence of visual cues distracts observers from processing verbal content. Although observers were able to identify truthful and deceptive verbal content accurately, they largely relied on visual cues in making judgments of veracity. Additional analyses suggest that subjects also relied heavily on visual information to make judgments of the actors' vocal behavior and overall behavior. These findings coincide with prior research; however, disconnrmation of the distraction hypothesis suggests that investiga-

Table 3 Average Evaluations of Verbal Content Deceptive verbal

Truthful verbal Truthful vocal

Deceptive vocal

Truthful vocal

Deceptive vocal

Condition

Rating

SD

Rating

SD

Rating

SD

Rating

SD

Deceptive visual Truthful visual

75.6 69.7

21.0 30.1

102.1 86.4

17.4 21.0

90.2 103.0

31.9 32.4

113.5 107.0

25.1 21.1

Note. N= 160. Low scores represent consistent, plausible, clear, and so forth verbal content ratings.


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tion of alternative explanations for the primacy of nonverbal cues is warranted. An alternative explanation for the primacy of nonverbal cues in deception detection is the situational familiarity hypothesis. According to this hypothesis, observers in unfamiliar situations have little basis for evaluating the validity of verbal content. When forced to decide, detectors seemingly use cultural norms for what a liar "looks like," because these norms are more informative than the verbal responses. Although verbal cues may validly signal deception, people unfamiliar with the deceptive situation may be unable to assess the utility of these cues for detecting deception. In familiar contexts, observers are able to "visualize" the situation in question and judge the plausibility and validity of verbal content. As a result, observers in familiar situations rely more on assessments of verbal content to make judgments of honesty and deceit. Much prior research on deception detection (including Study 1) required observers to make judgments about relatively unfamiliar situations. As a result, observers may have relied primarily on nonverbal information because they believed these cues were more informative. If so, then the situational familiarity hypothesis is a plausible explanation for the primacy of nonverbal cues in judgments of honesty and deceit. Considerable support for the situational familiarity hypothesis comes from research on social cognition. From a social cognitive perspective, deception is never actually detected; instead, deceptive intent is attributed to message sources on the basis of their behaviors. Detectors are thus subject to the influences of various cognitive biases and heuristics (Kahneman, Slovic, & Tversky, 1982) stemming from the fact that people seem to be cognitive misers (Taylor, 1981; Taylor & Fiske, 1978; Wyer & Srull, 1981). As a result, observers often use simple decision rules (e.g., representativeness heuristics) to make judgments about the behavior of others. In deceptive situations, such heuristics are reflected by the decision that nervous behavior is probably deceptive behavior. Chaiken (1987) argued that these simple decision rules often replace systematic message processing, particularly when individuals are unmotivated, unable to process message content, or both. When such rules are invoked, cues whose impact is mediated by use of these decision rules exert greater influence on judgments; conversely, when such rules are not used, message content cues exert the greatest influence on judgments. Applied to deceptive interactions, this reasoning suggests that when messages are systematically processed, verbal content cues provide the primary grounds for judgments of honesty and deceit; however, when messages are processed heuristically, extraneous nonverbal behaviors provide the primary grounds. The distraction and situational familiarity hypotheses differ subtly but importantly. The distraction hypothesis posits that detection errors result from an inability to process all of the information; the situational familiarity hypothesis posits that people can process visual, vocal, and verbal cue information simultaneously. It also holds that detection errors result from the relative importance that detectors assign to visual, vocal, and verbal information. In Study 2, we investigated this alternative hypothesis and assessed the effects of situational familiarity and verbal and nonverbal information on judgments of deception.

Study 2 Predictions The research reviewed in the previous section implies an interaction hypothesis concerning the effects of situational familiarity on judgments of deception. Specifically, people exposed to familiar situations should rely heavily on verbal information when making veracity judgments, whereas people exposed to unfamiliar situations should place greater reliance on nonverbal information. To test this hypothesis, we asked subjects to evaluate the veracity of an interviewee. The location of the event discussed in the interview was either familiar or unfamiliar to these subjects. In addition, each interview contained either truthful or deceptive verbal information and either truthful or deceptive nonverbal information. Thus, we predicted a main effect for verbal information in the familiar situation and a main effect for nonverbal information in the unfamiliar situation.

Method Design We used a three-factor independent-groups design. Two levels of verbal content (truthful and deceptive verbal information), two levels of visual information (truthful and deceptive), and two levels of situational familiarity (familiar and unfamiliar context) were completely crossed with each other.

Subjects Subjects were 151 undergraduate students enrolled in intermediate communication courses at a large midwestern university. Students volunteered to participate in the experiment and received extra credit for their participation. We assigned an additional 52 subjects to one of the verbal content control conditions and 35 to one of the visual content control conditions.

Stimulus Materials As in Study 1, we designed the stimulus materials to simulate truthful and deceptive behaviors while manipulating verbal, nonverbal, and situational familiarity cues. In all interviews, an actress played the role of an undergraduate student being questioned by a police officer (one of the investigators) about a recent automobile accident. The actress was trained to simulate truthful and deceptive behaviors by displaying different amounts of nonverbal cues and manipulating the verbal content of her responses. To test the familiarity hypothesis, all interviews dealt with either a familiar or an unfamiliar accident scene. Each of these manipulations is described in the following paragraphs. Verbal content. We manipulated interview content by having the actress respond to questions using either a truthful or a deceptive verbal script. Consistent with the findings of two previous studies (Kraut, 1978; Stiff & Miller, 1986), the verbal content of truthful messages was manipulated so as to be more consistent, plausible, and clear than the verbal content of deceptive messages. To check this manipulation, 52 raters read one of the two transcripts and evaluated the veracity of its verbal content. The truthful messages were judged to be significantly more truthful than the deceptive messages, fl(l, 50) = 59.70,p < .01, r = .74. Situational familiarity. We manipulated situational familiarity by varying the accident location discussed in the interview. In half the interviews the accident was described as having occurred locally, using


DECEPTION DETECTION street names, buildings, and events familiar to research participants. In the other interviews, the accident described occurred in a distant city unfamiliar to research participants. To test the effectiveness of this manipulation, 52 raters read one of the transcripts and evaluated the familiarity of the places and events described in it. The familiar transcript was rated as significantly more familiar than the unfamiliar transcript, F(l, 50) = 90.86, p < .01, r=.80. Nonverbal information. To simulate truthful and deceptive nonverbal behavior, the actress displayed various visual cues related to actual truthful and deceptive behavior described in previous research (Zuckerman et al., 1981; Zuckerman & Driver, 1985). We used four of these cues—adaptors, eye gaze, posture shifts, and hand shrugs—in the present study. The actress displayed more adaptors, indirect eye gaze, posture shifts, and hand shrugs when simulating deceptive nonverbal information. Vocal cues were not explicitly manipulated because the results of Study 1 indicated that the manipulation of visual information was sufficient to create perceptions of truthful and deceptive nonverbal behavior. As a manipulation check, two raters, blind to the manipulations, independently coded the nonverbal behaviors in each of the interview segments. Although we specifically manipulated only four visual cues, raters coded 12 different vocal and visual behaviors to determine if the actress unintentionally manipulated other visual or vocal behaviors. Interrater correlations for each of these 12 cues exceeded .90. As in Study 1, the unit of analysis was the average of the two raters' evaluations collapsed across the four response segments. Analysis indicated that the actress was able to manipulate the relevant cues effectively: She exhibited significantly more adaptors, F(\,6) = 243.00, p < .01, r = .99; posture shifts, F(l, 6) = 225.00, p < .01, r = .99; indirect eye gaze, /U, 6) = 101.40, p < .01, r = .97; and hand shrugs, P(l, 6) = 29.16, p < .01, r = .91, in deceptive than in truthful nonverbal information conditions. Collapsing across one of the three independent variables, a series of two-way ANOVAS revealed neither substantial nor significant interactions among the inductions. It was impossible to check for a three-way interaction because there was only one response per condition. In addition, there were no main effects or two-way interactions for the eight unintended cues (response time, response latency, response duration, pauses, sentence repairs, blinks, smiles, and hand wrenches), indicating that these cues were relatively constant across the experimental conditions. Using procedures described in Study 1, we estimated the influence of the visual cue manipulation on judgments of veracity. Thirty-five subjects watched one of the eight experimental interviews without verbal and vocal cues. Observers of interviews containing the truthful visual manipulations rated the actor as significantly more truthful than did those exposed to deceptive visual cues, F ( l , 33) = 15.73, p < .01, r = .57. Once again, the influence of the verbal cue manipulation (r = .74) was not significantly stronger than that of the visual cue manipulation (r = .57, z = 1.34). Thus, it is unlikely that any observed differences in the effects of visual and verbal information on judgments of veracity are related to the strength of the manipulations.

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pleted a brief questionnaire. They were then fully debriefed and asked not to discuss the study with others.

Measures The questionnaire contained five measures. The first was a single semantic differential-type question measuring participant judgments of the interviewee's veracity, and the second was a semantic differentialtype question assessing the extent to which they could visualize the events depicted in the interview. The third measure contained 11 semantic differential-type items used to measure believability of the interviewee's overall behavior, for example, tense-relaxed, consistent-inconsistent, and uniform-erratic (a = .94). We used a similar eight-item measure to assess the believability of the interviewee's visual nonverbal behavior (a = .92). Finally, we used a 12-item semantic differential-type measure, including such word pairs as clear-vague, specific-general, and direct-evasive, to assess believability of the verbal content (a - .96).

Results and Discussion Quality of Stimulus Materials The analyses indicate that the verbal, visual, and familiarity variables were manipulated effectively; that is, the intended differences in information were created. In addition, manipulation of these sources of information created the intended perceptions. Subjects evaluated the interviewee's overall behavior, F(\, 142) = 75.65,p < .01, r = .45, and visual nonverbal behavior, P(l, 142) = 117.83, p < .01, r = .63, as significantly less believable in the deceptive than in the truthful nonverbal information conditions. Subjects also evaluated the interviewee's overall behavior, F(1,142) = 137.70, p < .01, r = .61, and verbal responses, F(l, 142) = 333.19, ;?