How signs of fear can tell us everything and nothing.
Original excerpt published September 2009
Show no fear
Since the signs of fear look exactly the same for a liar afraid of being caught and a truthful person afraid of being disbelieved, signs of that emotion are useless unless there is reason to believe that only the liar will be afraid.
Fear increases the more that can be gained if the lie goes undetected. Similarly, fear increases with the severity of the punishment for being caught. The truthful person afraid of being mistakenly identified as a liar also will be more afraid when the threatened punishment for that mistaken judgment is severe.
“If you lie, I will catch you…”
In one of my research studies I gave the participants the opportunity to take money that wasn’t theirs and lie about it, or not take the money and truthfully proclaim their innocence.
When I began my interrogation I held up my book Telling Lies, saying, “I wrote this book. If you lie, I will catch you but if you tell the truth I will know it.” I was trying to increase the fear of being caught in those who were about to lie and decrease the fear of being mistakenly judged a liar, reassuring those about to be truthful.
Remembering the Scott Peterson Case
If a person has had successful lying experiences (especially with a particular lie) in the past – having multiple arrests but no convictions, carrying out affairs without ever being suspected, secretively partaking in drug use – generates confidence. Just as a target known to be suspicious increases fear, liars who have the opportunity to rehearse will be less afraid of being caught.
Studying Scott Peterson
Scott Peterson showed many examples of fear in his initial police interrogation. His wife Laci, eight months pregnant, was reported missing on December 24, 2002. After he changed his story about where he was when she disappeared, and his massage therapist girlfriend came forward revealing that he had told her two weeks before Laci’s disappearance that his wife was “lost,” the police became suspicious. A retired law enforcement officer and I reviewed a videotape of his first interrogation at the request of the local police. We did not then know the girlfriend’s story.
Peterson showed many micro expressions and some not-so-micro expressions of fear; still, we had to consider whether it might be an innocent husbands fear of being disbelieved. There were so many other forms of leakage that we were convinced he was the murderer. Peterson was sentenced to death. His case is on appeal to the Supreme Court of California. He maintains his innocence.