The field of verbal lie detection has grown rapidly in the past decade. Derived by the assumption that lies have different content patterns than do truths, research in this area promotes searching for content criteria to detect them. One prime content-based indicator for deception detection, which stems from the Reality Monitoring (RM) theory ( 1 ), is richness in detail . According to RM, truthful memories of actual events originate in perceptual experience and are embedded in the context of time and space. As such, they are expected to include more spatial and temporal contextual attributes (i.e., locations, spatial arrangement of people and objects, times, duration and sequence of events) and perceptual attributes (i.e., what the individual felt, tasted, smelled, heard, or saw when the event took place) than do false memories, which originate in self-generated thought or imagination. Derived from this prediction, the traditional use of richness in detail as an indicator of deception is based on the number of perceptual and contextual details in the interviewee's accounts. However, as a memory source-monitoring theory, RM does not take into consideration the intention of liars to deceive and consequently cannot explain the full scope of richness in detail in the field of deception ( 2 ). In contrast to false memories, where the individual has no intention to deceive but wrongly believes that his/her memory of an event that never happened is truthful, fabricated memories are an outcome of manipulation [and have thus been labeled “self-manipulated memories”; ( 2 )]. Liars frequently attempt to manipulate their fabricated accounts to make them seem truthful ( 3 – 5 ), for example by intentionally adding false perceptual and contextual details ( 6 , 7 ). Affecting the quantity of the details in their fabricated accounts, such strategic manipulations reduce the diagnostic efficacy of the richness in detail indicator. Yet, in the current paper, we aim to show that the same strategies leave traces on the quality of details. Therefore, we propose that to maximize the potential utility of the richness in detail indicator, it is necessary to dig deeper into the speech of liars, particularly by looking for traces of deception strategies found in the quality of the details. In fact, the Verifiability Approach [VA; ( 4 , 8 )] applies this notion. The Verifiability Approach (VA) The VA ( 8 ) for lie detection was initiated based on the understanding that lies, by nature, are based on strategies. The first VA study ( 4 ) clearly demonstrated that lie detection benefits more from consideration of the quality of perceptual and contextual details than it does from consideration of their quantity alone. According to the VA, the strategy employed by liars is guided by the liars' dilemma hypothesis . Specifically, liars perceive richness in detail as an indicator of truthfulness ( 9 , 10 ) and are thus motivated to provide many details to make an impression of honesty ( 7 , 11 ). On the other hand, the provision of details also puts liars at risk, as the truthfulness of the details provided can be checked. Aware of this danger [see ( 6 , 7 )], liars are inclined to avoid mentioning false details, to minimize the chances of being caught. These two contradicting motivations—for and against the provision of details—put liars in a dilemma. A strategy that resolves the conflict involves the provision of details that cannot be checked and verified. When used by liars, this strategy of providing non-verifiable information affects the quantity and quality of the contextual and perceptual details that appear in their accounts. They “inflate” the quantity of detail by incorporating false, non-verifiable, details, and as a result provide accounts that appear closer to the RM prototype of truthful accounts (i.e., accounts rich in perceptual and contextual details). However, their strategy leaves traces in the quality of their accounts, in terms of verifiability. By assessing the quality (i.e., the verifiability of the contextual and perceptual details) rather than the quantity of details provided, it is possible to reveal the liars' strategy, and thereby indicate their lies. In the last years, the validity of the VA, which was originally developed and tested in police interview setting [e.g., ( 4 , 5 , 12 , 13 )] has been examined in other settings including insurance [e.g., ( 14 – 17 )], airport security [see ( 18 , 19 )], occupation [e.g., ( 20 )], and malingering [e.g., ( 21 , 22 )]. Some of these applications were more successful than others, but mostly the VA perspectives were confirmed [for a recent review see ( 23 )], thereby providing an empirical evidence to the profitability of looking for quality of details. Encouraged by the success of the VA, we propose that research in this field should dig further into the speech of liars, in an attempt to identify additional indications of strategies in the quality of details provided. A
展开▼
