Earlier this year the nation was transfixed by the trial of Casey Anthony, a young woman accused of murdering her two-year-old daughter Caylee. During the course of the investigation Casey was interviewed on several occasions and she told many confirmed lies. The recorded interviews showed an apparently distraught but credible woman who revealed no specific cues of deception while fabricating explanations to account for her missing daughter. She explained away incriminating circumstantial evidence and blatantly lied to specific questions concerning her daughter’s disappearance with ease and confidence.

Casey was described by experts as being “comfortable” lying. While her detached affect, inappropriate attitudes and uncorroborated explanations accounting for Caylee’s disappearance certainly raised suspicions, she exhibited minimal nonverbal or paralinguistic symptoms of anxiety, fear, guilt or decreased confidence normally observed when a person tells a significant lie. In detection of deception jargon, Casey would be described as a “good” liar.

The average person is not a good liar. Typically when someone tells an important lie they will reveal symptoms such as averting eye contact or altering their posture. They may engage in grooming gestures like dusting imaginary lint from their clothing or fidgeting with an article of jewelry. A person guilty of wrong-doing usually displays particular attitudes like being unconcerned (“This is not important to me), unhelpful (“I have no idea what happened and have no information to help you”), unrealistic (“I don’t think that fire was intentionally started”) or guarded: (Q: “Tell me everything you did last Friday night.” R: “Nothing at all.”). The bad liar may qualify his response (“to the best of my knowledge”) or delay his response when answering a direct question.

To understand why some individuals are able to fabricate convincing stories and tell lies seemingly at will without revealing any observable symptoms of fear, guilt or decreased confidence it is first necessary to understand what causes the various “behavior symptoms” normally associated with lying. It is important to realize that these behavior symptoms are not caused by lying.

Actors who read scripted lies such as, “I’m a doctor, you must not move him!” do not display any behavior symptoms of deception. To the contrary, on the big screen they look absolutely credible. Even a lay person, relying on common sense and instincts, is able to make many false statements without revealing any signs of deception, e.g., “Johnny, you really played well today.” (Johnny played awful;) “Honey, that dress makes you look so young.” (The wife still does not look “so young”;) “I did not steal that money.” (The student, participating in a laboratory study, was instructed to lie when asked if he stole any money from the professor’s desk.)

The observable behaviors associated with lying result from the liar experiencing some internal emotional or cognitive state caused by the lie. These fall into three categories:

• Fear from having to face the consequences they are trying to avoid by telling the lie;
• Guilt or shame experienced from violating social mores or disappointing others, and
• Affected cognitive processes such as having “mental blocks” or inconsistent recollections, offering irrational explanations for evidence, etc.

In short, a “good liar” does not experience these internal changes when they lie (or does so in a diminished capacity). Listed below are common factors that may decrease behavior symptoms of deception when a person lies:

1. The suspect’s level of social responsibility. Suspects with low levels of social responsibility may not exhibit typical symptoms of deception when they lie. Individuals who fall within this category include drug, alcohol or gambling addicts, suspects who are homeless or individuals who are largely dependent on social services, parents or others to provide food, shelter, health care and basic survival. The absence of social commitment or responsibility to others causes these individuals to essentially live in their own world where they act impulsively and only for their own needs.

Individuals with low social responsibility tend to live in the immediate “here and now”; they have learned that it is not necessary to plan for the future because their future will be taken care of (or they simply don’t care about their future). This explains why such individuals sometimes get caught telling lies that are easily proven to be untrue. As an example, a suspect while under the influence of cocaine, threw his children off a balcony of his apartment resulting in their death. Upon initial questioning the suspect told the police that he had no children. After the investigator pointed to a photograph depicting the suspect with his children, the suspect confessed. Blatant, obvious lies of this nature are typical of suspects with diminished social responsibility and yet, when the lie is being told, specific symptoms of deception may be absent.

2. The suspect’s intelligence. Individuals with a lower IQ (below 65) often do not appreciate potential consequences of committing a crime, e.g., what life is like in prison; how a false allegation affects the accused, etc. As a result, when they lie, their fear of detection is decreased. Very simply, they are not highly motivated to avoid detection, and therefore, may not display symptoms of deception when they lie. For the same reason, they do not develop typical attitudes associated with deceptive suspects, e.g., being unhelpful, unconcerned or unrealistic.

3. Immaturity. This factor includes both youthful suspects (under the age of 9) and older suspects with an arrested social development. These individuals have little awareness or concern of serious consequences of wrong-doing and intellectually operate only in the here and now. In their minds they believe that the worst thing that could happen to them is having some restriction placed on their life (being sent to their room, being placed on probation) or other minor inconvenience (a verbal reprimand, paying a fine) when in truth, they could be facing life in prison. As a result, these suspects often lie impulsively and they may not display specific behavior symptoms of deception. Fortunately, with a little investigation, these lies are frequently detected through contradictory evidence.

4. Success at lying. A suspect who has experienced prior success at telling a lie may experience greater confidence and less fear of detection when repeating the same lie. After a lie is initially told and has been accepted as the truth, the liar not only has greater confidence of being able to get away with the lie a second time, but also has had practice at presenting the lie in a convincing manner. With each re-telling of the lie, the liar experiences greater confidence in their ability to fool others.1

6. Interview environment and format. It is not an uncommon occurrence for a person to address an audience, at a media press release for example, and tell blatant lies without exhibiting any symptoms of deception. There are two reasons for this. First, the liar is in total control of their statements. Under this circumstance the liar can carefully craft statements that are comfortable and can be delivered in a convincing manner. It is a one-way communication which the liar totally controls – they experience no fear of having statements challenged, expanded upon or otherwise scrutinized – in other words, the liar feels comfortable, confident and in control.

Second, psychologically lying to a group of reporters or millions of viewers on camera generates much less fear of detection than having to lie to a single person, sitting four or five feet in front of the subject, in a private environment. In this private environment the liar recognizes that the investigator is actively assessing his credibility, has control of the content of the interview through the questions being asked and, most importantly, has the ability to ask follow-up questions. Each of these factors increases the liar’s fear of detection.

7. Mental illness. There is a wide spectrum of diagnoses involving mental illness ranging from personality disorders through anxiety and affect disorders and finally disorders that cause loss of touch with reality such as bi-polar or schizophrenia. Within personality disorders, the histrionic and anti-social personalities tend not to experience significant guilt or fear when they lie and, therefore, may come across as good liars. The intermediate anxiety and affect disorders are much more likely to cause false positive errors (not believing a truthful person). Finally, suspects who have delusions or experience hallucinations will not exhibit meaningful behavior symptoms because their mind has created a new reality, and they have accepted what they are saying as the truth.

In summary, behavior symptom analysis involves making inferences about another person’s credibility and will never be a perfect science. Because of this, opinions of truth or deception should never be based solely upon a person’s behavior. Behavior symptoms should be considered along with evidence and other investigative findings. Finally, training in behavior symptom analysis should include not only information regarding truthful or deceptive behavior symptoms but also emphasize the factors that may lead to a mis-diagnosis of a person’s credibility – both false positive and false negative errors. This tip has focused on factors that may cause a liar to appear as credible. While some of these factors can be controlled by the investigator, e.g., interviewing a person in a private environment using a structured interview format, many of them are intrinsic within the suspect. Suffice it to say that before rendering any opinion of another person’s credibility it is important to evaluate factors that may affect the validity of that assessment and, whenever possible, attempt to verify a suspect’s verbal statements through standard investigative procedures.