Plausibility

A Subjective Cue

People usually depend on plausibility to distinguish lying from truth. However, plausibility is a subjective cue. Different lie detectors might interpret the same lie differently based on the plausibility of that lie. It is hard to draw the line between plausible and implausible. Perhaps the judging of plausibility could be more accurate when other objective factors are considered.

In addition, people not only use plausibility as a factor to determine whether others are lying, but they also use latency, a statement's vagueness and consistency, another party's smiling, as well as postural shifting and grooming to help them discriminate liars from truth-tellers. For example, when people give plausible answers, the hesitations before their answers are longer, and the answer itself is often overly long.

Plausibility of account is a verbal content behavior. Verbal content behaviors are easier to control than nonverbal behaviors. However, plausibility of content is associated with truthful contents most of the time, whereas other verbal content behaviors, such as contradictions and slips of the tongue, are indicators of lying and deception. Therefore, the verbal cues associated with truthfulness are more controllable, and liars can use many verbal content behaviors to create more credible and plausible accounts. Furthermore, liars also believe they are able to present greater plausibility, logical consistency, and response length than others when they try to provide a convincing account.

Especially when there is an opportunity for liars to develop a deceptive response, the planned lie is more plausible than spontaneous lies, and less likely to be detected. Time and opportunity are important for liars. They not only help liars develop a response with more plausible verbal content but also allow liars to inhibit nonverbal behavior cues, because nonverbal cues could be the main factor that distinguish planned lies from spontaneous lies. Planning increases the effectiveness and plausibility of lies, and makes planned deceptive responses more like spontaneous truthful responses.

A lie must have narrow plausibility to qualify as an assertion. Bald-faced lies do not need to have wide plausibility, which is the credibility relative to one's total evidence. But narrow plausibility is required by all assertions to at least make other people understand. When there is doubt about the plausibility of that assertion, liars might adopt sober tones and serious faces to evince sincerity.

...