LIE DETECTORS

Once again, in what is becoming something of a ritual, I've had an argument with several of the local police (who are friends and "shooting buddies" as well), over Lie Detectors.

Why are people so mermerized by this pseudoscience? Isn't the problem with such a device all too apparent?

I put my case as follows:

All "Lie Detectors" are fraudulent because they do not, in fact, detect lies.
They detect anxiety (to use a simple term).

Whether the tested subject's anxiety is actual, inferred, assumed and to what degree it can be quantified are all irrelevent.

In order for Lie Detectors to actually work, there would have to be a distinct, quantifiable physical manifestation of conscious dishonesty that ONLY occurs when a person is lying and NEVER occurs for other reasons.

I suggest calling this non-extant phenomenon the "Pinocchio Response."

Being that there is no Pinocchio Response, the only way Lie Detectors could work would be for them to literally read the subject's mind.

Since they have no such capacity, they do not and cannot detect lying. They cannot distinguish an honest but nervous man from a smooth liar.

My cop friends remained unconvinced, so I tried a different approach.

Imagine, I told them, that someone tells you he has invented a machine that can detect whether or not you find something truly funny - a joke, a humorous song, anything.

This machine, the Mirthometer, measures various physical phenomena related to feelings of amusement, such as facial muscles (smiling) and breathing patterns (laughing).

As a good skeptic, what would be your first concern about this gadget?

The subject could be faking!

People can and do feign amusement all the time. Haven't you ever laughed at an unfunny joke out of courtesy? How can you know the reactions are genuine?

Short of telepathy, you can't know.

Same thing with lying.