They're not useless, but yes, they are a form of trickery. It's a psychological technique that tries to make people who are lying or hiding things more likely to be nervous and more likely to confess (or be led down a line of questioning which eventually reveals new information).
The actual results from the machine are pretty much just a red herring, but that doesn't necessarily mean the machines have no valid uses. If use of a polygraph has helped tricked even one criminal into (truthfully) confessing or scared away even one person with malicious intent, then they're useful.
I wouldn't want a polygraph to be used for evidence in court, but I would want them to be used if I were interviewing for FBI/CIA/NSA. (But I definitely wouldn't want them to be used for firefighter and parademic positions.) I know it's a bit paradoxical that they can be both useful and a sham, but I think that's how law enforcement views them, too. This article presents a lot of issues with how they're used, but I wouldn't expect them to be phased out for a very long time (unless someone makes a version that actually has more scientific validity).
Polygraphs should nevern be used. An administrator can interpret the results any way they see fit. It's a perfect avenue for bigotry and other unfair hiring practices. It has no place in society.
Its not about the results and that lets the person running the test interpret things anyway they want. We have seen time, and time again that this leads to all sorts of discrimination that is both against our society's morals and not actually useful as filtering people as well the person doing the discriminating thinks.
> but I would want them to be used if I were interviewing for FBI/CIA/NSA
Why?
As well as being known to be a form of trickery it's also the case that it is easy to teach someone to manipulate the results at will.
All you achieve requiring it for those organisations is that there will be a) some who are rejected unjustly thanks to a false positive, and b) the people you really don't want in there have another bit of flim-flam to reinforce their apparent legitimacy.
Yes, undoubtedly there are good candidates who are weeded out due to false positives, but there are probably many bad candidates who are weeded out due to true positives (or don't apply at all because they fear the test). It will lead to bad actors who study the test and pass it, but that's why it's critical that law enforcement agencies do not use a passed test as indication of trustworthiness; merely an initial barrier to entry to be passed. The trustworthiness has to come from a thorough background check and normal interviewing.
As long as the examiners, recruiters, interviewers, and higher-ups fully understand polygraphs are a trick and nothing more, I still think they serve a useful purpose for three-letter agency hiring.
I don't support the use of homeopathy, but I don't think that's a great analogy. Polygraphs are used as an interrogation technique, where psychological tricks and deception on the part of law enforcement are "fair game" (we could enter a long discussion as to whether or not deception during interrogations/interviews should be permitted, but regardless, that's the status quo right now).
Trickery and deception when it comes to medicine and personal health are never fair game. I think there's definitely a difference between police telling a suspect "we know you did it" (when they don't actually know) and a doctor telling a patient "take this and you'll feel better" (when the drug actually does nothing).
Also, polygraphs are a little bit more functional than homeopathic medicine: a polygraph can not only induce nervousness, but can also notice it in some cases (even if the nervousness may not be concerned around a particular question and may not necessarily indicate deception and even if there are false positives). This helps create a feedback loop which makes it more powerful than a pure placebo (e.g. a "lie detector machine" you hook someone up to which isn't powered on at all and does literally nothing).
It's been shown that telling someone you're giving them a placebo can still bring benefit, in which case I'm okay with it. But giving someone a placebo or homeopathy pill (same thing) and failing to disclose it contains no active ingredient is pure deception, unless the patient has given consent that they may receive a placebo, like if they're in an experimental trial. Even if someone does show improvement after receiving the placebo, it's never justifiable to outright lie to them.
The actual results from the machine are pretty much just a red herring, but that doesn't necessarily mean the machines have no valid uses. If use of a polygraph has helped tricked even one criminal into (truthfully) confessing or scared away even one person with malicious intent, then they're useful.
I wouldn't want a polygraph to be used for evidence in court, but I would want them to be used if I were interviewing for FBI/CIA/NSA. (But I definitely wouldn't want them to be used for firefighter and parademic positions.) I know it's a bit paradoxical that they can be both useful and a sham, but I think that's how law enforcement views them, too. This article presents a lot of issues with how they're used, but I wouldn't expect them to be phased out for a very long time (unless someone makes a version that actually has more scientific validity).