The Art & Science of Lie Detection

1. The Art & Scienceof Lie Detection Laura Freberg, Ph.D. Professor of Psychology California Polytechnic State University, San Luis Obispo laura@laurafreberg.com

2. Today’s Agenda • What is a lie? • Why do people lie? • When are they easy or hard to “catch?” • How do people telegraph their truthfulness? • What are the emerging technologies in lie detection? • A quick video of body language during a lie

3. What Is a Lie? According to the American Heritage Dictionary, a lie is: 1. A false statement deliberately presented as being true; a falsehood. 2. Something meant to deceive or give a wrong impression. Note the emphasis on the person’s intent.

4. Types of Lies • “Protective” lies: Telling children that the stork brought them because you don’t think they’re old enough to talk about sex, or reassuring your relative that he/she is not really terminally ill • White lies: Lies that do no harm, and may do good, such as complimenting your hostess’ meal even if you didn’t enjoy it much (social tact) • Lying by omission: Failing to reveal one’s belief in order to deceive. • Bluffing: Usually considered more of a tactic than a lie, as it occurs in the well-understood context of a game.

5. More Types of Lies…. • Jest: When we use sarcasm or tell tall tales, we assume others understand we are deliberately not telling the truth. • Careful Speaking: Avoiding the telling of an outright lie with carefully chosen words; a half-answer that is accurate but does not fully answer a question.

6. The Morality of Lying • Many philosophers (e.g. Kant, Thomas Aquinas) prohibited ALL lying, even if it meant death. • Lying is a misuse of the human faculty of speech. • Lying undermines trust, which is essential to the community. • Lying undermines others; Lying makes a decision for the other person, rather than letting him/her decide based on facts. • Others defend lying, such as telling a Nazi soldier that one has no Jewish children in the house.

7. Why Do We Lie? We are not alone. Deception is common in the animal kingdom. All animals (including us) deceive others to obtain benefits or avoid costs.

8. Lying in Animals • Koko, the female gorilla who uses American Sign Language, signed “cat did it,” when confronted with a sink she had damaged during a tantrum. It is not clear whether or not Koko was making a joke or lying. • Wolves often “bluff” during ritual fighting that maintains the hierarchy within the pack.

9. The Development of Lying • The ability is universal. • Children demonstrate “Theory of Mind” at about the age of 4 years. Simultaneously, they are capable of lying effectively. • The ability to lie precedes a moral understanding about the importance of honesty. Consequently, children lie frequently until they learn that this results in negative consequences. • Adults probably lie as frequently as children, but about different things.

10. Even Robots Will Learn to Deceive • Laurent Keller’s robots react to theenvironment with a computerized “genome.” • Bots that find food “mate” with other successful bots and send their “genome” into the next generation. Bots can turn blue lights on and off. • Bots “evolved” the ability to communicate with lights. Some flashed their lights near food, while others flashed their lights near poison. • Bots gave correct information to “relatives,” but flashed their lights far away from food when surrounded by “strangers.”

11. “Catching” a Liar Liars will look different ONLY when the following two conditions are fully met: • The person is deliberately and knowingly telling a lie. • The person thinks lying is wrong.

12. Reconstructive Memory • When we retrieve information from memory to use it, the data are at risk for change. The person retrieving changed, inaccurate information will believe that he/she is telling the truth. • Elizabeth Loftus and Eyewitness Testimony • Loftus (1975) • N=150 • Video of an automobile accident • IV “How fast was the white sports car going when it passed the barn while traveling along the country road?” “How fast was the white sports car going while traveling along the country road?” • DV – measured one week later “Did you see a barn?”

13. Loftus’ Results

14. When People Don’t Care…. • People who do not believe that lying is wrong will show few, if any, detectable signs of arousal. • Psychopaths, criminal or not, are incapable of empathy or guilt. Therefore, they do not perceive that harming others is a problem, and will be effective liars.

15. Signs That a Person Is Lying Detecting lies in people you know is FAR easier than detecting lies in a stranger. When dealing with strangers, use baseline questions that nobody would lie about to establish “normal” behavior. Assuming a person is deliberately lying AND recognizes lying as negative, you may observe some/all of the following: • Reduced articulation • Facial and body responses that do not “match” • Facial and body responses that pass quickly are are replaced by more “conscious” responses

16. More Signs of Lying • Reduced upper body movement • Increased lower body movement • Nervous smiling or laughter that is inappropriate given the topic under discussion (smiling is a submissive signal—I’m okay, don’t hurt me) • Eye contact (works in the generic American culture, but few others) • Timing: Emotions are spontaneous, instantaneous reactions to our environment. Any delay in reaction should be suspect.

17. Traditional Lie Detector Tests Polygraph tests are reliable about 65% of the time, even when conducted by experts. Consequently, they are not admissible in court.

18. Other Tech Efforts • “Truth serum” • Brain fingerprinting • fMRI • Brain activity during the processing of real memories and imagined events is identical. • fMRI requires cooperation (no moving) • Cannot detect lies by omission • CAN detect if a person is thinking about a place versus a face • CAN detect extra brain activity required by lying

19. Other Challenges for fMRI • Small number of participants • Generally typical, law-abiding participants without psychopathology • Can we generalize from the laboratory (no risk) to the courtroom (huge risk)? Lying Truth

20. Ethics of New Technologies • Technology generally moves much faster than corresponding discussions of ethics. • What if we can “read” the brain? How should that be used? What protections should we have for participants?

21. Thank you! Any Questions? Feel free to email me laura@laurafreberg.com Or visit me on the web at: http://www.laurafreberg.com