In brief: Why the innocent confess
Why the innocent confess
About 20% of proven wrongful criminal convictions result from false confessions. Research based on psychological experiments and case records and summarized in a 2005 article in the journal American Psychologist suggests some reasons for this shocking situation.
Police investigators sometimes say they are not worried about false confessions because they do not interrogate innocent people. What they mean is that before starting an interrogation, they have already been persuaded — by preliminary interviews, witnesses, criminal profiling, or simply a hunch — that the suspect is guilty and lying. They judge the success of the interrogation by their ability to extract a confession.
Although the vast majority of people who undergo interrogation may be guilty, there is no reliable way to tell whether someone is lying. Shifty eyes, fidgeting, slouching, apparently rehearsed responses, signs of either high or suspiciously low anxiety — none of these are useful cues. Experiments show that police detectives and polygraph examiners are no better than anyone else at distinguishing truth from lies. In fact, several studies suggest that training and experience in the use of standard police interrogation techniques may raise the risk of error because it enhances confidence — almost always with a bias toward guilt — but does not improve accuracy. And there is some evidence that observers are better at detecting lies than the person conducting an interrogation.