Lying and deception are an extremely common interpersonal experience. Nearly everyday, while carrying out interpersonal relationships, one can expect to either witness or be the conveyor of a deception. Deception can be defined as an intentional verbal message that does not honestly reflect an individual’s actual opinion (Zuckerman, DeFrank, Hall, Larrance, & Rosenthal, 1979). Quite often the lie or deception is of little consequence, and perhaps may even be expected due to societal norms. Many can predict the consequences of an unpleasant truthful response to a either a supervisors questioning of an employee regarding work satisfaction and their feelings about the management, or a spouse’s loaded question, "do I look fat in these pants."

High stakes examples of deception, however, can have serious consequences for both the individual attempting to deceive and the victim of the deception. In the majority of criminal investigations crimes are rarely solved by scientific analysis and sleuthing alone (Horvath, Jayne, & Buckley, 1994). Often these investigative approaches are not applied to a particular case until a potential suspect has been identified via interrogation or interviewing. Additionally, many types of criminal investigations (i.e., sexual assaults) often provide very little physical evidence regarding the act (Porter & Yuille, 1995). It is thereby the responsibility of the investigator to identify guilty suspect's deceptive attempts, while at the same time the suspect is strongly motivated, by the potential loss of freedom, to be an excellent deceiver. Unfortunately, due to the common usage of deception in our every day lives, individuals are more practiced at deceiving then at detection (deTurck & Miller, 1990).

The difficulty in identifying deceptive behavior has lead to scientific investigations into the nature of deceptive behavior and its assessment. The uses of pure physiological measures of deception, such as the polygraph and galvanic skin response (GSR), have provided promising results (Porter & Yuille, 1995). However, the high rate of false positives (the incorrect identification of truthful individuals as deceptive) produced by these measures is counter-intuitive to the "innocent until proven guilty" stipulation that most modern legal systems support (Lubow & Fein, 1996). Other measures of deception (i.e., forensic hypnosis, narcoanalysis) have been investigated, but often produce even greater ethical dilemmas (Porter & Yuille, 1995).

Intriguing anecdotal accounts have been suggestive of potential "human lie-detectors", based upon an individual’s own ability to predict deception via cues observed during interpersonal contact with a deceiver (Frank & Ekman, 1997). One particularly famous example of this comes from the writings of Avner Less (1983) the interrogator of the Nazi officer and war criminal Adolf Eichmann. Less noted that Mr. Eichmann consistently displayed specific cues during the interrogation that were useful in directing further probing. In particular, whenever Eichman would say "Never! Never! Never, Herr Hauptmann," or "At no time! At no time," Less notes that Eichman was lying.

Even more promising results, regarding the possibility of human lie detection, comes from research on the analysis of the non-verbal behavior of deceivers (Harrison, Hwalke, Raney, & Fritz, 1978; Kraut & Poe, 1980; Lubow & Fein, 1996; Zuckerman, DeFrank, Hall, Larrance, & Rosenthal, 1979). Research has consistently showed the presence of a variety of non-verbal cues that are particularly characteristic of an individual presenting a deceptive account. The analysis of non-verbal behavior appears to be a promising avenue of deception research. Additionally, its application outside of the laboratory setting is of interest to numerous forensic contexts.

Laboratory and field research on the ability to detect deception has provided mixed results. Several studies have provided significant findings regarding the possibility of the effective detection of deception via behavioral observation (deTurck & Miller, 1990; Horvath, Jayne, & Buckley, 1993). However, several other studies have contributed to these findings, showing subject detection rates that are significantly below those expected by shear chance (Ekman, 1992; Gudjonnson, 1992). An understanding of the underlying processes of deception, the deceiver, and the deception evaluator may help to clarify the conflicting data found in the literature.

In order to better understand the nature of deception, its behavioral correlates, and its detectability, it is helpful to first understand the underlying processes that provide the framework for deceptive communication. Vrij and Winkel (1993) stated that the deception framework includes both emotional and cognitive components. Emotionally the process of deception can initiate a stress reaction via guilt regarding the deceptive act or from fear of detection and the potential response to such a revelation. The resulting stress reaction manifests itself with the activation of the sympathetic nervous system. This activation drives a number of potential innate verbal, non-verbal, and paralinguistic behavioral responses designed instinctually as a component of the fight and flight system typically activated in times of stress (deTurck & Miller, 1990). Physiological measures (i.e., GSR, polygraph, blood pressure) comparing sympathetic arousal during deceptive tasks have consistently supported these assumptions (Vrij, 1994).

At the point of sympathetic arousal, the cognitive component of the deception-behavior framework is activated (Vrij & Winkel, 1993). The control hypothesis states that an individual who is sympathetically aroused is cognizant of their nervousness and will thereby attempt to limit and control any behavioral cues they perceive as being created by the stressor (Vrij, 1994). Initially the individual will try to control all perceived behavioral cues of deception. While many potentially behavioral cues are salient to the individual, others are either perceived as less relevant or not consciously perceived at all. The Individual will tend to focus their cognitive processes upon the more salient factors, while often negating the others (DePaulo, Lanier, & Davis, 1983). Additionally, the relative conscious controllability of the salient behavioral cues is variable. A behavioral channel with high controllability is one with an elevated sending capacity and a heightened degree of internal feedback (DePaulo, Lanier, & Davis, 1983). Sending capacity refers to the number of distinct messages that can be transmitted by a channel. The degree of internal feedback considers the extent to which an individual is aware of the channels output and their ability to change this information. A behavioral channel with both a high sending capacity and level of internal feedback would be of considerable aid to acts of deception. One such channel (the verbal channel) has the ability to present a wide variety of information that an individual is both clearly aware of and easily able to manipulate. A different pattern holds true of microexpressions. Microexpressions are "brief and incomplete facial expressions that occur on individuals’ faces very quickly after exposure to a specific stimulus and before active processes can be used to conceal them" (Baron & Byrne, 1997, pg. 49). Such a channel is likely a hindrance to the disguising of deception. Microexpressions have the potentiality of displaying a multitude of affective states, while at the same time are difficult to self-monitor and nearly, if not, impossible to inhibit.

Even with the most salient and controllable channels there is still the potential of self-monitoring and behavioral manipulation backfiring. If an individual attempts to control to many channels concurrently a cognitive overload may occur, and subsequently the attempted behavioral manipulations will fail (DePaulo, Lanier, & Davis, 1983). Additionally, the illusion of transparency may inappropriately influence behavioral manipulations. This illusion refers to an individual’s overestimation of the detectability of their internal states. As a result, individuals may overcompensate with their behavioral manipulations, creating behaviors that appear clearly artificial (Gilovich, Savitksy, & Medvec, 1998).

Regardless of the nature of the deficit that produces it, there are two unique types of behavioral cues that may be produced in the context of deception, leakage and deception cues (Frank & Ekman, 1997). Leakage cues involve non-verbal revelation of a message regarding ones internal state, which may be counter-intuitive to the deceptive message the individual is trying to express. The previously mentioned microexpressions would be an example of this cue, via its presentation of a message regarding the internal affective state of the deceiver. Deception cues are non-verbal behaviors that are suggestive of the likelihood that the conveyor of the cue is attempting to deceive. An example of this would be nervous finger tapping or eye contact shifting. While these cues are suggestive of deception, the nature of the act is unknown. Since deception cues are more a physiological reaction, compared to the cognitively involved leakage cues, the deception cues are independent of context and are thereby considered a more universal cluster of deception-behavioral correlates (Kraut, 1978).

Once the behavioral cues are transmitted regarding potential deception, the deception framework shifts from the deceiver to the evaluator-receiver. The interpersonal dynamic between deceiver and judge is a complex one. At its most basic level the deceivers behaviors are evaluated within a expectancy-violation model. The expectancy-violation model postulates that the deception evaluator will differentiate between expected and inconsistent non-verbal behavior as it relates to the current context, other non-verbal behaviors, and the verbal dialogue occurring (Bond, Jr., Omar, Pitre, Lashley, Skaaggs, & Kirk, 1992). Expected non-verbal behaviors are presumed to be accepted at face value, while inconsistent non-verbal behavioral cues are thoroughly scrutinized resulting in a complex examination of other cues, the potential deceivers motivation, and any other available information. If the individual’s veracity is brought into continued doubt and alternative explanations of the behavioral information are inadequate, deception is likely presumed to be occurring (Bond, Jr., Omar, Pitre, Lashley, Skaaggs, & Kirk, 1992).

DeTurck and Miller (1990) note that with the exception of arousal in general, there is no common or universal behavioral cue set that identifies deception across all individuals. While the presence of a universal cue would be convenient, the usage of behavioral information still can contribute a great deal to deception prediction if appropriately analyzed. DePaulo (1992) states that observing the consistency and match between an individual’s non-verbal behavior and the concurrent verbal-linguistic message can be highly predictive of deception. Research has shown hat the usage of such an approach can often come quite naturally and is significantly predictive (Rotenberg, Simourd, & Moore, 1989).

Since it is suggested that all behaviors be compared to the concurrent verbal information, an examination of the non-linguistic verbal behavior is pertinent. It has been noted that speech has a function beyond the verbal conveyance of semantic information (Streeter, Krauss, Geller, Olson, & Apple, 1977). Non-Linguistic cues within verbalizations can display an individual’s affect and sympathetic arousal (stress) by variations in pitch, amplitude, and rate of articulation (Streeter, Krauss, Geller, Olson, & Apple, 1977). Variation in pitch frequency has been one of the most frequently and consistently observed behavioral variations of deception (Vrij, 1994; Zuckerman, DeFrank, Hall, Larrance, & Rosenthal, 1979). Streeter, Krauss, Geller, Olson, and Apple (1977) showed subjects an extremely unpleasant surgical film and required them to later describe the film to a confederate as either pleasant (deception condition) or unpleasant (truthful condition). Subjects in the deception condition, compared to their honest counterparts, had a significantly elevated pitch frequency when describing the film to the confederate. The increased frequency is thought to be the result of heightened physiological tension brought forth by the sympathetic arousal-deception reaction (Walters, 1996). An individual’s ability to ascertain pitch variation, and subsequently infer honesty or deception from such an observation has been empirically demonstrated (Streeter, Krauss, Geller, Olson, & Apple, 1977). Unfortunately, subjects did not appear to use this information unless directed to do so.

Further non-linguistic behavioral cue research has identified a number of additional speech disturbances predictive of probable deception. Variations such as decreased rate of articulation, speech hesitations, and response brevity have all proven to be predictive of deceptive behavior (Burgoon & Buller, 1994; Harrison, Hwalke, Raney, & Fritz, 1978; Kraut, 1978; Mehrabian, 1971; Vrij, 1994). These non-linguistic speech disturbances appear to be directly related to an individual’s mental processing status (Walters, 1996). When an individual is experiencing low levels of arousal and stress (i.e., while conveying honest information) their speech is characterized as having a consistent, repetitive, and almost rhythmic pattern. However, when an individual is experiencing increased arousal (i.e., while deceiving) their speech pattern becomes slowed, inconsistent, broken, and with increased speech errors due to a dramatically increased amount of cognitive processing that is occurring (Walters, 1996). Occasionally, a deceiver's speech rate may dramatically increase. This is believed to be the result of the presentation of a question or inquiry that the deceiver had anticipated and prepared for (Walters, 1996).

Horvath, Jayne, and Buckley (1993) presented a general behavioral profile of the truth-telling and deceptive subject. They stated that an honest (and innocent) suspect, when questioned, tends to be helpful, expects exoneration, displays resentment towards the guilty party, and appears both spontaneous and sincere. A deceptive (and guilty) suspect provides less helpful information, shows inappropriate concern about being a suspect, lacks response spontaneity and sincerity, and uses both guarded and clearly edited verbal responses. Horvath and colleagues proposed profile variation between truth-tellers and deceivers is consistent with a number of research findings (Burgoon & Buller, 1994; Kraut, 1978).

Deceivers and truth-tellers also appear to differ in their response to perceived suspiciousness from the interrogator. A truthful individual will typically respond in a means consistent with what they have already been reflecting. By maintaining what has already been established without embellishment the possibility of being caught putting up a false front is eliminated. The deceptive individual, however, tends to respond to suspiciousness with increased embellishment, often falsely, upon what has already been presented (Weiler & Weinstein, 1972).

Walters (1996) stated that human communication consists of 65% body language, 12% voice quality, 7% verbal content, and 16% of additional factors (i.e., chemical, and odor). People appear to be significantly more practiced and successful at controlling verbal behavior than non-verbal behavior (Walters, 1996). Therefor, it would seem most appropriate to explore the nature of non-verbal deception cues and their applicability to lie-detection.

One of the most salient, and consistent, non-verbal behavioral deception cues are the previously mentioned microexpressions. Negative microexpressions can be briefly "leaked" in a number of forms: unpleasant voice shifts, brief head shaking and most importantly as negative facial expressions (Burgoon & Buller, 1994; Mehrabian, 1971). Walters (1996) notes that individuals are typically cognizant of their own primary expressions. Additionally, he states that one may be equally aware of the ability of many others, particularly skilled investigators, to decipher such non-verbal behavior. As a result when in a deceptive situation one will typically try to disguise such behavior. However, as was previously mentioned it is highly unlikely that one can significantly control microexpressions. Therefor, the displaying of the controlled and stable expressions are inconsistent with any uncontrolled microexpressions that may be presented. Subsequently, non-verbal channel discrepancies are produced (Lubow & Fein, 1996). Frank and Ekman (1997) provided empirical evidence supporting the effectiveness of microexpressions as a deception leakage cue. In their study it was found that 90% of deceivers presented negative microexpressions during questioning, while only 30% of truth-tellers displayed any such behavior. Additionally, they found that microexpression leakage was relatively consistent across subjects and gender, thereby suggesting its applicability as one of the more universal behavioral deception cues. Aside from the mere variation of microexpressions between the two experimental groups (deceivers and truth-tellers) it was found that microexpressions did significantly aid in the deception judgements of naive evaluator subjects. Those individuals who consistently used microexpressions as their primary cue of deception were significantly better at predicting deception than those who did not.

Anecdotally, a great number of people will state that they can tell if an individual is being honest by looking into their eyes. As well, many are familiar with the expression "the eyes are the window to the soul." It would appear that deception research provides some evidence that these common beliefs hold true (Horvath, Jayne, & Buckley, 1993; Lubow & Fein, 1996). Walters (1996) states that any break in an individual’s normal level of eye contact, if occurring in an appropriately timely fashion, is a potential sign of stress regarding the immediate context or line of questioning. Deception cue studies that included polygraph analysis support the conclusion that eye contact variations occur concurrently with the stress related arousal present during deception (Horvath, Jayne, & Buckley, 1993).

The type of eye contact variation appears to be different depending on the nature of the deceiver. Introverted liars show a dramatic decrease in eye contact, while extroverted deceivers show an increase in eye contact (Walters, 1996). It is possible that the introverts response is a "flight" reaction attempting to disassociate themselves from the stress of the deceptive situation, while the extraverts bolstered their interpersonal presence via increased eye contact as a "fight" reaction either to challenge the interrogator or because they believed it increased their perceived sincerity.

Pupillary size variations have also been shown to be a relatively stable deception cue. Lubow and Fein (1996) examined the relationship between pupillary size and an individual’s performance on the guilty knowledge test. The guilty knowledge test presents an individual with non-crime related neutral information along with non-crime information that it is presumed only the guilty party would know. It is thought that a guilty individual will show a significantly greater autonomic reaction to the crime-based information than an innocent subject would. In the experiment subjects who had participated in a mock-crime were significantly more likely to display increased arousal when exposed to photographs of the crime scene. This arousal was clearly correlated with the increased mean pupillary size of deceptive subjects. While this cue appears to be a consistent and universal indicator of potential deception, the ability for individuals to consistently note pupillary variation has not been investigated and may very well be a difficult observation to regularly note.

A less salient and more complicated, yet still predictive, cluster of deception cue behavior are the signals provided by posture and body movements. Horvath, Jayne, and Buckley (1993) created a profile of postural and body movement variations of truth-tellers and deceptive individuals. According to their findings an honest individual typically displays a comfortable, open, and forward leaning posture. The deceptive individual is characterized by a more rigid, generally frozen, and defensive posture.

The rigid and frozen nature of postural shifts and body movements is a consistent finding (Mehrabian, 1971; Vrij, 1994). One could be surprised by this finding, expecting that the heightened autonomic arousal developed during deception would lead to an increase in nervous body movement. However, the body movement non-verbal cue channel is typically one of relatively high controllability. Consistent with previously mentioned illusion of transparency, it appears that individuals may be overcompensating the inhibition of body movements to an extent that is suspect to an evaluator of deception (Horvath, Jayne, & Buckley, 1993).

It does appear that the deceptive communicator will occasionally show evidence of increased movements. One particular example occurs when an individual is attempting to disguise a channel that they consider more revealing (Ekman & Friesen, 1974). Walters (1996) notes that some of the more common disguising movements include: the covering of ones mouth, or even briefly ones face, to disguise any revealing facial expressions; and secondly the breaking of eye contact during times of particular stress via the usage of an interfering body movement (i.e., adjusting ones glasses).

The typical deceiver also tends to present a posture defined by researchers as "defensive" (Horvath, Jayne, & Buckley, 1993). Typical of this posture is the backward lean, arm crossing, and leg crossing. When an individual is feeling threatened and stress increases, it appears that one often carries out a postural shift into a "defensive" position that acts as a proximal barrier for the individual. This in turn creates a more comfortable, and thereby less stressful, environment.

While there appears to be a number of behavioral cues regarding deception that are consistent and relatively universal across subjects, research has shown that there is a great deal of difference between the detectability of liars, and that these individual liars tend to be consistently good or bad at the act of deception (Kraut, 1978). One could thereby presume that if there is such variability between the effectiveness of deceivers, then these factors must exist regarding either the liar or the lie that contribute to detection success.

One would clearly expect that self-monitoring is an essential component of deception. The usage of self-monitoring acts as a method to increase impression management, and thereby decrease the potential of deception detection (Littlepage & Pineault, 1984). Since deception involves the manipulation of verbal and non-verbal information, one must carry out self-monitoring in order to evaluate which cues are being displayed. Additionally, one must assess the extent to which the individual’s manipulation of cues is creating the desired effect. Research has shown that individuals with high levels of self-monitoring ability, as compared to those with low self-monitoring ability, are significantly less likely to be detected when attempting to deceive (Miller & Stiff, 1993). It is thought that high self monitors are not only better able to evaluate and manipulate their behavior, because of a heightened cognitive awareness of their own presentation, but that they are also more practiced at impression management due to the increased usage of self-monitoring behaviors in their everyday lives (Miller & Stiff, 1993; Riggio & Friedman, 1983).

Rehearsal also appears to play a role in the effectiveness of deception. Miller and Stiff (1993) hypothesized that rehearsing would have the ability to enhance the credibility of ones deception. They presumed that the act of rehearsal prior to deception would allow an individual to "cognitively play out" the deceptive act, leading to lower levels of stress, arousal, and nervousness. Subsequently, this act would be expected to decrease the presence of verbal, non-verbal, and paralinguistic deception cues. Research upon rehearsal and the usage of planned versus spontaneous lies has created a complex picture regarding the effects of rehearsing ones deceptive act (Littlepage & Pineault, 1984; Vrij, 1994; Zuckerman, DeFrank, Hall, Larrance, & Rosenthal, 1979). Littlepage and Pineault, (1984) found that planned (rehearsed) lies did indeed appear to be more credible to evaluators than spontaneous ones. However, while the plausibility does appear to be increased it seems to be limited to verbal cues (Vrij, 1994). The number of non-verbal cues of deception were actually significantly higher with planned lies than with spontaneous ones (Littlepage & Pineault, 1984; Vrij, 1994). It appears that individuals who rehearsed their deceptive acts were limited to expressing deception cues on the verbal cue channels, while being unable to keep other deception cue behaviors stable (Zuckerman, DeFrank, Hall, Larrance, & Rosenthal, 1979). Untrained lie detectors tended to focus on the verbal cues when evaluating deception (Littlepage & Pineault, 1984). However, if there was a suspicion of potential deception, judges tended to use non-verbal cues, subsequently predicting deception at a more appropriate rate (Littlepage & Pineault, 1984). The effect of rehearsing on the deception judgements of professional lie-catchers, who often analyze non-verbal behavior, can be predicted to lead to higher rates of detection compared to spontaneous liars.

Some researchers have postulated that an individual’s expressiveness may play a key role in ones ability to be a successful deceiver. Expressiveness refers to an individual’s degree to which emotional reactions are apparent to others from that individual’s facial expressions, particularly when the individual is not purposefully conveying the emotion (DePaulo, Blank, Swaim, & Hairfield, 1992). DePaulo and colleagues (1992) identified deceivers and truth-tellers as being either low or high in expressiveness ability. Individuals who were low on measures of expressiveness were found to be bad deceivers. These individuals were significantly identified as being deceptive to a greater degree than their expressive counterparts. Expressive deceivers and truth-tellers could not be differentiated from each other by the judges. In this experiment high expressive individuals presented as more convincing. However, there is concern about the real world generalizability of the expressiveness findings. This particular design involved a deceptive act that evoked little emotion. Whether individuals of high expressiveness could disguise their true emotional reactions in a highly emotional context is a valid question. Further research in this area could very well find that in such a context the results would be reversed, with low expressive individuals better able to hide the negative emotions that would betray their deception.

Motivation has proven to be an important factor behind both the effectiveness of deception and the interpretation of the mixed and conflicting results within the lie detection literature. Ekman (1992) showed student nurses an extremely unpleasant film, asking them to later describe it to a second individual. Motivation was manipulated by informing the students that career success would be predicted by their ability to convey unpleasant information as being pleasant. Results showed that professional lie detectors were better able to identify motivated deceivers than their non-motivated counterparts. Additionally, it was found that these lie detectors needed only to consider the nursing student's non-verbal behavior to make effective deception judgements. Ekman (1992) later replicated the high-motivation non-verbal results, adding that individuals with low motivation were more readily detected via verbal cues. Gustafson and Orne (1963) claim that such results provide clear evidence that high motivation to lie is a key factor in lie detection, in that heightened arousal due to the emotionality of high stake lies is what leads to increased arousal and deception cue leakage. This is suggestive that the negative laboratory deception findings may not be externally valid, due to an inability to replicate the emotionality and arousal brought forth by real life interrogations. Larson (1922) investigated this idea outside of the laboratory, finding that when deception motivation was high "leakage" cues were present, but when motivation was low they were not. Interestingly, he also noted that following confession "leakage" cues ceased. One could presume that motivation to deceive had thereby dissipated. Supporters of the academic literature have argued that most lies in everyday life are of low arousal (DePaulo, Lanier, & Davis, 1983). However, while no one would argue this fact, the applicability of lie detection strategies is not primarily concerned with every day lies.

Professionals within occupations concerned with deception detection often believe that some individuals are better at detecting lies then others. Australian customs officers note that specific individuals always have the highest rate of contraband recovery, police organizations always use the same individuals to train officers in interrogation, and some professional poker players are clearly better at reading deception then others (Frank & Ekman, 1997).

Empirical research regarding the success of individual deception judgements have been mixed. A study by Kraut (1978) suggested that it is the situation, not the evaluator, that is predictive of deception judgements, stating that there was no relationship between a deception judges ability across different deceivers. However, Frank and Ekman (1997) question these findings reporting the presence of a number of methodological concerns within the study. Meanwhile, other studies have shown individual judges consistently obtaining deception judgements success rates as high as 80%, while other test subjects were consistently below rates expected by chance (Vrij, 1994). Frank and Ekman (1997) compared the predictive success of subjects with left-hemisphere brain damage to an undamaged control population. Left-hemisphere brain damage prevents the ability to process verbal information. The brain damaged subjects, who could only process non-verbal information, significantly outperformed, regarding deception judgements, the non-damaged controls. Overall, research appears to support the anecdotal beliefs that some individuals are better lie detectors than others.

Since some individuals clearly outperform others regarding deception evaluations, one could assume that an individual who acquires those characteristics or skills present in the successful evaluator will subsequently improve their deception evaluations. Zuckerman, Koestner, and Alton (1984) questions whether these skills are best acquired by practice or training. It has been stated that improvement requires advanced concept formation, and therefor behavioral cues must be consistently distinguished by both training and practice via application of the learned techniques (Rosenthal, Hall, DiMatteo, Rogers, & Archer, 1979).

Research on the success of lie detection training has been encouraging, with detection rates consistently above 70%, and even in one study of real world experts reaching a predictive success rate over 90% (DePaulo, 1992; deTurck & Miller, 1990; Horvath, Jayne, & Buckley, 1993; Zuckerman, Koestner, & Alton, 1984). One encouraging study noted that the effect of training on the detection of deception in subjects considered masterful deceivers was significantly improved (deTurck & Miller, 1990).

The practicing of learned lie detection techniques with feedback regarding success or failure of judgements, along with information regarding the nature of these success for failures, has been shown to increase predictive success beyond training alone (deTurck & Miller, 1990; Vrij, 1994). It is believed that feedback allows subjects to learn individually which cues from their training are the most salient to them (deTurck & Miller, 1990).

One concern with the reliance on approaches that teach universal cues of deception is the extreme variation in such behaviors naturally seen across different individuals. Some individuals are more lively and subsequently present with more body movements than others, others are more expressive and thereby more convincing, while another group of individuals with low social skills naturally come across as deceptive (Vrij, 1994). Vrij (1994) warns that these factors can create either an honest or dishonest demeanor bias, which can significantly effect any deception evaluations. Walters (1996) states that these biases can be avoided, and at the same time greatly improve the validity of deception judgements, via the formation of behavioral baselines. With baseline formation, behavioral cues of interest are first observed when the individual is not deceiving (i.e., during demographic or crime unrelated questioning) in order to create an individual normative profile. It is following this that any timely alterations in behavior that are considered possible deception cue "leakage" are investigated further. Studies incorporating baselines into their deception assessments have shown significant improvement on deception judgements, and have displayed the applicability of training across deceivers (deTurck & Miller, 1990; Horvath, Jayne, & Buckley, 1993).

Another concern that has been raised regarding lie-detection training is the possibility of artificially inflated confidence regarding ones ability to detect deception. Considering the only marginal success of naive evaluators, untrained judges have unwarranted and remarkably high levels of confidence in their deception judgements (Vrij, 1994). Research has found, however, that the difference between accuracy and confidence in individuals who have received lie-detection training is actually lower than in their untrained counterparts (Horvath, Jayne, & Buckley, 1993). Whether this is due to a more dramatic increase in accuracy than confidence, or that awareness of the difficulty of deception evaluations makes confidence judgements more realistic, is uncertain.

One training model and deception assessment instrument in common use today is J.E. Reid and Associates Behavioral Analysis Interview (BAI). The BAI is a 30-45 minute long empirically derived structured interview designed to elicit verbal and non-verbal behaviors and attitudinal characteristics of the suspect in a non-accusatory manner (Horvath, Jayne, & Buckley, 1993). Initially, questions concern only the suspect's background. This is done to establish a relationship with the suspect and to determine normative (baseline) information for the behavioral cues of interest. The second phase consists of investigative questions used to assess the individual’s opportunity, motivation, and involvement with the issue at hand. Finally, the investigator uses behavior-provoking questions to elicit differential verbal and non-verbal behaviors.

Validation studies of the BAI have been promising. Horvath, Jayne, and Buckley (1993) reported a 91% accuracy in assessing honest responses, and a 80% accuracy in predicting deception. The BAI allows one to evaluate substantially more information then is typically assessed without such an instrument or in laboratory research. Its high rates of success in validation studies, along with its ease of application and training, have made it a very popular instrument and in increasing demand.

The ability to detect deception is an area of particular interest to a number of unique environments. In criminal investigations competent interrogation techniques are often fundamental to the successful gathering of evidence for further scientific analysis. The failure of many popular deception detection techniques to provide a valid measure with limited false positives (false identification of deception), along with the ethical concerns surrounding other methods of deception analysis, has led to a great deal of interest in the assessment of deception via behavioral observations (Lubow & Fein, 1996).

Research has consistently shown that a combination of autonomic arousal and cognitive processing failures can create a number of identifiable non-verbal cues of deception (Horvath, Jayne, & Buckley, 1994). Factors such as, non-linguistic voice characteristics, microexpressions, and body-movement are all predictive of a deceptive individual. Walters (1996) notes, however, that there is no single universal cue of deception. He postulates that one must examine an individual's non-aroused behavior prior to any emotionally stressful and arousing interrogation is undertaken, so that a baseline of normative behavioral responses can be formulated for comparison with any observed behavioral cues.

The usage of deception detection training programs and structured interviews, most notably the BAI, have shown a dramatic increase in the ability to detect detection, particularly when applied to real world interrogations (Horvath, Jayne, & Buckley, 1994). The applicability of lie-detection research to real world contexts is currently in high demand and appears to be a possible avenue of significant contribution to many forensic contexts.

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