Let Their Words Do the Talking

Verbal cues to detect deception.

Poor Man's Polygraph Part 5

The Parallel Lie provides an additional indicator of veracity.

Poor Man's Polygraph Part 5

Parallel Lie


People tend to tell the truth except when the truth prevents them from achieving a desired outcome. The next time you purchase a product or service use the Poor Man's Polygraph to give yourself a degree of confidence that you are not being cheated. Likewise, parents use the Poor Man's Polygraph, more aptly described as the Parental Polygraph, to test the veracity of your kids. Kids, especially teenagers, tell their parents the truth when they know their parents will approve of their activities and become evasive or even outright lie when they know their parents will disapprove of their activities. The time to worry is when kids become evasive or deceptive because they know they have either done something they know their parents would not approve of or they are reluctant to discuss a sensitive topic. These are the precise times when parents should uncover the truth and provide direction and guidance for their children.

Find a Therapist

Search for a mental health professional near you.

The Poor Man's Polygraph provides indicators of deception, not proof of deception. No one verbal cue indicates deception, but the probability of deception increases when clusters of deceptive indicators are present. The Poor Man's Polygraph gives you the necessary tools to protect yourself in a deceptive world. The Poor Man's Polygraph and other verbal techniques to detect deception can be found in a booklet titled Catch a liar.

The Parallel Lie technique is the last part in the five part series presenting the Poor Man's Polygraph. The Parallel Lie is a stand-alone technique or can be used as a follow-on technique to the question "Why should I believe you?" The "Why should I believe you technique?" was discussed in Part 4 of this series. The Parallel Lie does not repeat the initial question but, rather, asks the person about the veracity of their initial response. As review the "Why should I believe you?" technique is demonstrated below:

INVESTIGATOR: Did you rob the bank?

SUSPECT: No.

INVESTIGATOR: Believe it or not people have lied to me in the past to get out of trouble. I don't know you very well and you don't know me very well, so why should I believe you?

SUSPECT: Because there was no way I could have been at the bank that day because I was at a friend's house.

INVESTIGATOR: I didn't ask you if you if you could have been at the bank that day. I asked you Why should I believe you. Tell me, Why should I believe you?

SUSPECT: You don't have to believe me. I don't care.

INVESTIGATOR: Well, I don't believe you.

The failure to respond "Because I'm telling the truth or some derivation thereof increases the probability of deception. Failing to provide the correct response to the question "Why should I believe you?" is only one indicator of deception, not proof of deception. No one verbal cue indicates deception, but the probability of deception increases when clusters of deceptive indicators are present.

The Parallel Lie provides an additional indicator of veracity. After some passage of time from asking the question "Why should I believe you?," the investigator introduces the Parallel Lie technique. The investigator does not ask the suspect the question, "Did you rob the bank" a second time but, rather, asks him about his response to that question. The Parallel Lie can either address the truthfulness of the person's response of the deceptiveness of the person's response. For example:

INVESTIGATOR: Sir, remember when I asked you if you robbed the bank and you said, ‘No.' Were you lying to me?

SUSPECT: Ah...no.

INVESTIGATOR: I knew you were lying to me.

SUSPECT: I don't care what you think.

Responding to the Parallel Lie requires additional cognitive processing. Truthful people do not experience cognitive overload; they simply convey facts. Liars, on the other hand, are operating at near-full or full cognitive capacity depending on the complexity of the lies. Liars have to remember what they said and did not say. They also have to monitor and control their verbal responses and nonverbal behaviors. Additionally, liars have to monitor their target's verbal responses and nonverbal behaviors to ensure that the target believes the lie. The mind of a liar is fully occupied. When people lie, especially in high stakes lies, they use all or most of their cognitive capacity to maintain the lie.

The Parallel Lie causes a person to think because rarely are people asked about the veracity of their response to a question. Truthful people have little difficulty processing new information because they have excess cognitive processing capacity. Conversely, liars use all or most of their cognitive processing capacity to maintain their deception and have little excess capacity to process new information. Since liars are operating at or near full cognitive capacity, they have trouble processing these types of questions and will often hesitate for a moment before answering.

When the suspected liar hesitates, a presumptive should be introduced. Presumptives challenge veracity. Persumptives such as "I knew you were lying" or "Don't lie to me directly challenge veracity. Persumptives can also be more benign. For example, "I didn't think you were being truthful." or "I thought there was more to the story." Indirectly, suspected liars are put on notice that their stories are not wholly believed. Honest people tend to protest to some degree after being called liars and in many cases display emphatic gestures. Dishonest people tend not to protest after being called liars or become defensive. Even if truthful people hesitate when answering the question, they will usually provide push back after being called a liar. Observing the interviewee's verbal and nonverbal reaction to the question is more important than the answer itself.

Additionally, the suspect's response, "I don't care what you think." is another deceptive indicator. Truthful people do care if they are believed or not and typically provide pushback. Truthful people rarely show indifference when they are not believed, especially when the stakes are high. The suspect displayed a cluster of three deceptive indicators, which further increases the probability of deception. Again, the Parallel Lie technique does not, in and of itself, indicate deception but it does add support to the hypothesis that a person is being deceptive, especially in conjunction with other deceptive indicators.

Parents can use these techniques on their children to test their veracity.

Example 1:

DAD: When you told me you weren't drinking at the party last night, were you telling me the truth?

Example 2:

MOM: When you told me you didn't hit Mary as school today, did you lie to me?

The Parental Polygraph and other techniques to detect deception and to identify sensitive topics kids, for various reasons, do not want to discuss can found in Fibs to Facts: A Parental Guide to Effective Communication.

John R. "Jack" Schafer, Ph.D., earned his degree in psychology from Fielding Graduate University, Santa Barbara, California and served as a behavioral analyst for the FBI.

more...

Subscribe to Let Their Words Do the Talking

Current Issue

Just Say It

When and how should we open up to loved ones?