We ought to know this by now, but the press still breathlessly reports it when people fail polygraph tests as if that meant something. (In the Annie Le murder investigation, I only wish it did, but the suspect's alleged defensive wounds mean more.)
The National Academy of Sciences has found that most studies purporting to investigate the polygraph are bad science ("the substantial majority of the studies most relevant for this purpose were below the quality level typically needed for funding by the National Science Foundation or the National Institutes of Health...Almost a century of research in scientific psychology and physiology provides little basis for the expectation that a polygraph test could have extremely high accuracy"). (Unfortunately, the federal government doesn't appear to have read the NAS report.)
The National Academy of Sciences has found that most studies purporting to investigate the polygraph are bad science ("the substantial majority of the studies most relevant for this purpose were below the quality level typically needed for funding by the National Science Foundation or the National Institutes of Health...Almost a century of research in scientific psychology and physiology provides little basis for the expectation that a polygraph test could have extremely high accuracy"). (Unfortunately, the federal government doesn't appear to have read the NAS report.)
Let the polygraph go the way of the wedding ring on the string, folks.
1 comment:
A few years ago, there was a significant push to reincarnate the polygraph using functional brain mapping. At the time, being a graduate student in a neuroimaging lab, I have introduced the idea to our PIs, who turned to polygraphic expertise of Nathan Gordon. He swore, in conversations with me, to 95% accuracy of the classic polygraph tests. In my opinion, the polygraph test was an inherently unstandartised procedure, with at best variable degree of accuracy. This is why I thought that fMRI might present a method to directly assess the state of lying. Eventually, Gordon published a paper with with my PIs -- http://bit.ly/4jK2aF, and the gang was consulted by the government. By then, however, I was turned off on the idea, because I felt that the fMRI was being abused as a "sixth needle," to validate the polygraph tests rather than establish markers of lying and to characterize the process of lying. The biggest problem with this idea is that even though we are pretty good at mapping brain activity in various tasks, we aren't as good at understanding and interpreting all the hot spots. So what if one's amygdala is lighting up? -- it lights every time one experiences the sense of fear, regardless of its cause. One scientist proposed that lying requires more mental work and memory processing. Therefore, we should expect to see more activation showing up in frontal and limbic pathways. However, is it really reflective of lying about being in the room where the alleged crime has been committed, or displaying a mental image of that because I work there? In other words, unique physiological substrates of lying are not known, and to find them, we should ask right questions, and not abuse fashionable technology.
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