In addition to polygraph "testing," some agencies may require a psychological evaluation, part of which may be yet another pseudoscientific technique: the Rorschach test, also known as an ink blot test.

You'll find a detailed description of the Rorschach test, including outline traces of the ink blot charts used, and responses that psychologists consider indicative of normality or abnormality, at:

http://www.deltabravo.net/custody/rorschach.htm

and additional commentary at:

http://www.deltabravo.net/custody/rorschach2.htm

I find the parallels between these two pseudoscientific techniques (polygraphy and the Rorschach "test") to be striking.

I am a psychology lecturer covering lie detection for a module on Investigative Psychology, part of a Criminology degree. I have 3 weeks for this topic and I want to get over the utter lack of validity of all biological 'magic key' methods. The polygraph is easy (thanks to your work), I can work up the voice stress methods, but I can't find good info on the other methods (eg 'truth drugs'; the latest eye muscle monitoring; etc). Does anyone have some advice?
We expect our students to become police officers, prison & probation, support workers for people in trouble with the law, etc. I want to give them enough confidence, based on sound evidence and argument, to stand up for the just position when they are part of the team making decisions about using polygraphs, etc.
The block will end with a session on behavioural indications of stress, how these might be interpreted reasonably and a little on the psychology of deception.
If anyone has any ideas for practical exercises to bring home the key points, these would also be welcome.
(I always credit anyone who contributes ideas, etc, and I'll be glad to tell you how it goes. This module first runs in 2003, they will start careers in late 2004 so the most important test - how this changes their practice - will be some time coming.
The concentration on the legal side is because this sort of testing is not widespread in the UK, let's keep it that way!
I am considering a similar small block aimed at voodoo testing in business but that will probably emphasise rubbish like graphology.)
Thanks for reading to end,
Keith (not sure how to use smileys so played safe)

Keith,

I'm not sure where to find information on "truth drugs" (the term "truth serum" is sometimes heard in the U.S.) or eye muscle monitoring, but I think The Skeptic's Dictionary will be a useful resource. See especially the section on Junk science & Pseudoscience."

In the United States, one sometimes hears of law enforcement officers consulting with self-professed "psychics" or clairvoyants for assistance in solving crimes. Perhaps some in the U.K. have indulged in the same idiocy. With regard to supernatural claims, in addition to the aforementioned site, see also the James Randi Educational Foundation and the Committee for the Scientific Investigation of Claims of the Paranormal. Now, claimed supernatural powers may seem a bit beyond the purview you described, but you did express an interest in the psychology of deception, and I think material on these sites such as Randi's short article, The Art of Cold Reading will be of interest. (With regard to polygraphy, is it not, at its core, a purported exercise in mind reading?)