In an earlier post I described how the Justice Department had been trying for decades to get police to learn and use effective questioning techniques. It seemed like the “TOP COPS” were not training their officers.
Here is some supplemental research which emphasizes that criminal justice system lie-catchers (embarrassingly even judges) are seriously flawed at detecting liars and explains why we read about innocent people being sent to prison and guilty people going free. It also explains why the jury system of laypersons is an essential source of justice. The source documents are referred to below; they have more detailed information, describe any limitations on their findings, including why some of the results may be understandable and where additional research might be needed.
In an article published in the journal Psychology Crime and Law 9(1):19-36, December 2001, the authors examined beliefs about deception held by three groups of legal professionals who we often expect to be expert lie-catchers: police officers, prosecutors, and judges.
Judging from self-ratings, THE PRESUMED EXPERTS ADMITTED KNOWING CLOSE TO NOTHING ABOUT SCIENTIFIC RESEARCH ON DECEPTION.
The majority of the police officers believed that liars are more gaze aversive than truth-tellers.
WRONG
The research shows that no relationship exists between gaze aversion and deception; some studies even show that liars are less gaze aversive than truth-tellers
Judges, prosecutors and police officers expressed a very strong belief that deceptive consecutive statements are less consistent than truthful consecutive statements.
WRONG
Research shows that deceptive statements are at least equally consistent over time as are truthful
statements.
The majority of the police officers believed that there is an increase in body movements during deception.
WRONG.
Importantly, both experimentally based research, and studies of real-life interrogations shows that liars often move less than truth-tellers.
Judges and prosecutors believed verbal cues to deception to be more reliable than nonverbal cues. Police officers believed nonverbal cues to be more reliable than verbal cues when attempting to detect deceit.
HERE, JUDGES AND PROSECUTORS WERE MORE ACCURATE THAN POLICE
Research shows that lie-catchers trusting verbal cues judges and prosecutors tend to achieve higher accuracy scores than do lie-catchers trusting nonverbal cues police officers.
PRISONERS, COMPARED TO PRESUMED EXPERT LIE-CATCHERS, SHOULD HAVE THE BEST NOTION OF NONVERBAL INDICATORS OF DECEPTION, DUE TO THEIR MORE ADEQUATE FEEDBACK HISTORY.
A doctoral dissertation examined similar issues and found similar results.
[I]ndividuals overwhelmingly believe that liars exhibit behaviors that indicate nervousness. These “nervous” behaviors, however, include fidgeting, stuttering, avoiding eye contact, etc., all of which are likely to be controlled by a competent liar. In high-stakes situations, such as police interviews, TRUTH-TELLERS SOMETIMES DEMONSTRATE MORE NERVOUS BEHAVIORS THAN LIARS.
A review of laboratory studies in 1991 found the ACCURACY RATE FOR LAYPERSONS who were attempting to detect deceit WAS 57%, NOT MUCH BETTER THAN RANDOM CHANCE. They then examined studies that included professionals such as local, state and federal LAW ENFORCEMENT OFFICERS and found that the ACCURACY RATE WAS 55%, not only not much better than chance but less accurate than laypersons.
In a 2016 presentation to TED Talks, a researcher reported that, again, professionals (lawyers, police officers, child protective services workers, even parents) were not much better at detecting lies than if they had simply flipped a coin.
The researchers showed many videos to adults to gauge how good they were at detecting children’s lies.
In half of the videos, the children lied. In the other half of the videos, the children told the truth. BECAUSE THERE ARE AS MANY LIARS AS TRUTH TELLERS, IF YOU GUESS RANDOMLY, THERE'S A 50 PERCENT CHANCE YOU'RE GOING TO GET IT RIGHT. So IF YOUR ACCURACY IS AROUND 50 PERCENT, IT MEANS YOU ARE A TERRIBLE DETECTOR OF CHILDREN'S LIES.
So let's start with undergrads and law school students, who typically have limited experience with children. No, they cannot detect children's lies. Their performance is around chance.
Now how about social workers and child-protection lawyers, who work with children on a daily basis? Can they detect children's lies? No, they cannot.
What about JUDGES, CUSTOMS OFFICERS AND POLICE OFFICERS, who deal with liars on a daily basis? CAN THEY DETECT CHILDREN'S LIES? NO, THEY CANNOT.
What about parents? Can parents detect other children's lies? No, they cannot.
Can parents detect their own children's lies? No, they cannot.
Sources:
How to Detect Deception? Arresting the Beliefs of Police Officers, Prosecutors and Judges
Article (PDF Available) in Psychology Crime and Law 9(1):19-36 · December 2001
LINK TO RESEARCHGATE
Abstract of the Dissertation: The Effect of Cognitive Load on Deception,
by Terri Patterson, Florida International University, 2009 - LINK
TED talk: Kang Lee: Can you really tell if a kid is lying? February 2016
LINK to TED TALK
Here is some supplemental research which emphasizes that criminal justice system lie-catchers (embarrassingly even judges) are seriously flawed at detecting liars and explains why we read about innocent people being sent to prison and guilty people going free. It also explains why the jury system of laypersons is an essential source of justice. The source documents are referred to below; they have more detailed information, describe any limitations on their findings, including why some of the results may be understandable and where additional research might be needed.
In an article published in the journal Psychology Crime and Law 9(1):19-36, December 2001, the authors examined beliefs about deception held by three groups of legal professionals who we often expect to be expert lie-catchers: police officers, prosecutors, and judges.
Judging from self-ratings, THE PRESUMED EXPERTS ADMITTED KNOWING CLOSE TO NOTHING ABOUT SCIENTIFIC RESEARCH ON DECEPTION.
The majority of the police officers believed that liars are more gaze aversive than truth-tellers.
WRONG
The research shows that no relationship exists between gaze aversion and deception; some studies even show that liars are less gaze aversive than truth-tellers
Judges, prosecutors and police officers expressed a very strong belief that deceptive consecutive statements are less consistent than truthful consecutive statements.
WRONG
Research shows that deceptive statements are at least equally consistent over time as are truthful
statements.
The majority of the police officers believed that there is an increase in body movements during deception.
WRONG.
Importantly, both experimentally based research, and studies of real-life interrogations shows that liars often move less than truth-tellers.
Judges and prosecutors believed verbal cues to deception to be more reliable than nonverbal cues. Police officers believed nonverbal cues to be more reliable than verbal cues when attempting to detect deceit.
HERE, JUDGES AND PROSECUTORS WERE MORE ACCURATE THAN POLICE
Research shows that lie-catchers trusting verbal cues judges and prosecutors tend to achieve higher accuracy scores than do lie-catchers trusting nonverbal cues police officers.
PRISONERS, COMPARED TO PRESUMED EXPERT LIE-CATCHERS, SHOULD HAVE THE BEST NOTION OF NONVERBAL INDICATORS OF DECEPTION, DUE TO THEIR MORE ADEQUATE FEEDBACK HISTORY.
A doctoral dissertation examined similar issues and found similar results.
[I]ndividuals overwhelmingly believe that liars exhibit behaviors that indicate nervousness. These “nervous” behaviors, however, include fidgeting, stuttering, avoiding eye contact, etc., all of which are likely to be controlled by a competent liar. In high-stakes situations, such as police interviews, TRUTH-TELLERS SOMETIMES DEMONSTRATE MORE NERVOUS BEHAVIORS THAN LIARS.
A review of laboratory studies in 1991 found the ACCURACY RATE FOR LAYPERSONS who were attempting to detect deceit WAS 57%, NOT MUCH BETTER THAN RANDOM CHANCE. They then examined studies that included professionals such as local, state and federal LAW ENFORCEMENT OFFICERS and found that the ACCURACY RATE WAS 55%, not only not much better than chance but less accurate than laypersons.
In a 2016 presentation to TED Talks, a researcher reported that, again, professionals (lawyers, police officers, child protective services workers, even parents) were not much better at detecting lies than if they had simply flipped a coin.
The researchers showed many videos to adults to gauge how good they were at detecting children’s lies.
In half of the videos, the children lied. In the other half of the videos, the children told the truth. BECAUSE THERE ARE AS MANY LIARS AS TRUTH TELLERS, IF YOU GUESS RANDOMLY, THERE'S A 50 PERCENT CHANCE YOU'RE GOING TO GET IT RIGHT. So IF YOUR ACCURACY IS AROUND 50 PERCENT, IT MEANS YOU ARE A TERRIBLE DETECTOR OF CHILDREN'S LIES.
So let's start with undergrads and law school students, who typically have limited experience with children. No, they cannot detect children's lies. Their performance is around chance.
Now how about social workers and child-protection lawyers, who work with children on a daily basis? Can they detect children's lies? No, they cannot.
What about JUDGES, CUSTOMS OFFICERS AND POLICE OFFICERS, who deal with liars on a daily basis? CAN THEY DETECT CHILDREN'S LIES? NO, THEY CANNOT.
What about parents? Can parents detect other children's lies? No, they cannot.
Can parents detect their own children's lies? No, they cannot.
Sources:
How to Detect Deception? Arresting the Beliefs of Police Officers, Prosecutors and Judges
Article (PDF Available) in Psychology Crime and Law 9(1):19-36 · December 2001
LINK TO RESEARCHGATE
Abstract of the Dissertation: The Effect of Cognitive Load on Deception,
by Terri Patterson, Florida International University, 2009 - LINK
TED talk: Kang Lee: Can you really tell if a kid is lying? February 2016
LINK to TED TALK