@Daniel Sumner is totally right. Polygraph is unreliable and spies are trained to beat it. It is based on stress level. It detects persons heartbeat and pulsereate. So, yeah If you are trained and have antisocial personality disorder, you can easily passed it with flying colors.
For anyone interested in these topics, a great author is Aldert Vrij. His book 'Detecting Lies and Deceit' is a really useful comparative look at some of the main ways that are used to detect deception. And which ways seem to offer more promise than others, and which have some scientific backing and research.
Most would assume the polygraph is the best way, but in fact isn't very useful at all. The polygraph relies on stress and that is what it detects not deception, so may fail since innocent people feel stress and many psychopaths who lie freely may lie freely without feeling the accompanying stress or fear of not being believed.
The work of Ekman is interesting, and relies on discrepancies between facial expressions, body language (manipulators, gestures) etc to detect deception.
One interesting finding is that seasoned investigators often perform no better at the detection of deception than laypeople, and so deception detection informed by the findings of psychology are absolutely crucial.
One of the mian problems of lie detection is the plethora of misinformation, for instance: 'that people who lie avoid eye contact'. This is completely false, in that there are a variety of conditions such as being on the autism spectrum which may cause you to avoid eye contact out of comfort rather than deception. Also, this myth has become so prevalent that now people tend to stare down interviewers in the hope of being believed.
Psychologists such as Ekman, emphasise the importance of establishing a baseline, or a pattern of behaviour that the individual normally exhibits. If this behaviour changes one has to figure out broadly why and what is motivating this change in posture, voice intonation, gaze, facial expression. Usually stress markers may point to a sensitive topic but does not outright indicate deception.
It's a rich subject and well worth the time investigating.
Thanks for sharing this post.
Recommended books:
Vrij. A 'Detecting lies and deceit'.
Ekman P. 'Telling Lies: Clues to Deceit in the Marketplace, Politics, and Marriage'.
@Daniel Sumner is totally right. Polygraph is unreliable and spies are trained to beat it. It is based on stress level. It detects persons heartbeat and pulsereate. So, yeah If you are trained and have antisocial personality disorder, you can easily passed it with flying colors.
For anyone interested in these topics, a great author is Aldert Vrij. His book 'Detecting Lies and Deceit' is a really useful comparative look at some of the main ways that are used to detect deception. And which ways seem to offer more promise than others, and which have some scientific backing and research.
Most would assume the polygraph is the best way, but in fact isn't very useful at all. The polygraph relies on stress and that is what it detects not deception, so may fail since innocent people feel stress and many psychopaths who lie freely may lie freely without feeling the accompanying stress or fear of not being believed.
The work of Ekman is interesting, and relies on discrepancies between facial expressions, body language (manipulators, gestures) etc to detect deception.
One interesting finding is that seasoned investigators often perform no better at the detection of deception than laypeople, and so deception detection informed by the findings of psychology are absolutely crucial.
One of the mian problems of lie detection is the plethora of misinformation, for instance: 'that people who lie avoid eye contact'. This is completely false, in that there are a variety of conditions such as being on the autism spectrum which may cause you to avoid eye contact out of comfort rather than deception. Also, this myth has become so prevalent that now people tend to stare down interviewers in the hope of being believed.
Psychologists such as Ekman, emphasise the importance of establishing a baseline, or a pattern of behaviour that the individual normally exhibits. If this behaviour changes one has to figure out broadly why and what is motivating this change in posture, voice intonation, gaze, facial expression. Usually stress markers may point to a sensitive topic but does not outright indicate deception.
It's a rich subject and well worth the time investigating.
Thanks for sharing this post.
Recommended books:
Vrij. A 'Detecting lies and deceit'.
Ekman P. 'Telling Lies: Clues to Deceit in the Marketplace, Politics, and Marriage'.