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Polygraphs must not be used as they are completely unreliable and subject to many issues.

The government does a lot of security theater and campaigns to make you believe that they are competent.



It's interesting to note that the scandal going on in Israel wrt/ the chief prosecutor of the IDF leaking a prisoner abuse video was uncovered in a polygraph test.

"A routine Shin Bet polygraph test of a senior officer close to Military Advocate General reportedly exposed new clues about video leak, prompting Attorney General Gali Baharav-Miara to order a full criminal investigation"

https://www.ynetnews.com/article/bkbichbjbe

While polygraphs are not perfect they are widely used as part of a broader set of measures. I'm not sure "must not be used" is really the right way to approach this. This person would not have been caught if it wasn't for this polygraphs screening.


>This person would not have been caught if it wasn't for this polygraphs screening.

The organization whose crimes she exposed claims she would not have been caught if its wasn't for the polygraph screening. Corrupt law enforcement types love things like polygraph tests because they give them a ready avenue for parallel construction.


That was my own interpretation... but admittedly maybe too strong of a statement. Maybe she would have be caught. That said, the psychological setup in those periodic interviews with a "maybe lie detecting machine" create opportunity to find real issues.

In terms of the details here, the leak wasn't to expose the crimes, it was to resist political pressure [my speculation anyways]. The crimes were being investigated anyways and the video was available internally fairly broadly (and I think maybe externally as well). There was a political storm as a result of the investigation and the arrests made. Apparently leaking the video is was not illegal (though that's subject to some interpretations) because the role of the chief prosecutor is independent but this became more complicated when it required lying to the supreme court to cover the leak.

But yeah, it's possible the Shin Bet already had an idea but just used the polygraph as an excuse/opportunity. While it's understandable in the political climate why the chief prosecutor would leak the video it's also unethical and poor judgement for someone in her role to do so, and then to cover it up. The role of the Shin Bet is to find people in sensitive roles who are secretly doing things they should not be doing (typically spies but more generally people betraying the trust put in them). For those not following, the plot got thicker because she proceeded to throw her iPhone in the Mediterranean and it was found by a swimmer some days later. She also tried to harm herself. It's pretty crazy stuff. Now there are arguments about who should oversee the investigation with the supreme court set to decide today. It's a pretty small/tight legal community and everyone knows everyone, especially at the top. The legal system has been in a battle with the government for some while with the justice minister refusing to accept the last appointment of the chief justice of the supreme court.

Anyways, the polygraph angle is interesting. That this machine survives as a practice in many places tells us something about its usefulness (or at least people's belief in its usefulness).


About a decade ago, "magic wand" bomb detectors and similar products were pretty big among security services in places like Iraq. [1] Their various supposed methods of operation were transparent BS, in ways that make the EM drive proponents look rigorous.

What always struck me about reporting on them was how there was a great deal of coverage about how fraudulent they were, but seeming puzzlement on why security services would keep buying such obvious BS. What seemed clear to me, was that the BS was the point. Similar to polygraphs and drug-sniffing dogs, the purpose of the tool is to give the investigator a seemingly-objective excuse to follow their intuition (or engage in arbitrary targeting and abuse; take your pick).

1. https://en.wikipedia.org/wiki/ADE_651


I was once in an airport in some third world country and one of those dogs was pointed at my luggage. I was really worried their operator would give them some secret signal to find "drugs" in my luggage. Nothing happened but I can imagine that's a thing.

Those wands were completely fake. Dogs do have a keen sense of smell and can be trained to sniff certain substances.

The polygraph I think is more in the disputed category. It actually measures some physiological signals which in theory could correlate to stress.

That said I don't disagree. These tools can be abused. At the end of the day you need various checks and balances in all these systems (e.g. FBI's internal investigation or whatever body is involved in the security clearances in the US in this example). Applying psychological pressure in various ways is a legitimate tool in these domains.


> A routine Shin Bet polygraph test of a senior officer close to Military Advocate General reportedly exposed new clues about video leak...

It should probably read, "A senior officer exposed clues during a polygraph test..."

The polygraph is a McGuffin. The interviewer applies pressure by psychologically manipulating the suspect. That's all the polygraph is, psychological manipulation.


Maybe. The same can be said for placebo. But if it works - it works.


There is really no evidence that it works, even in that way though.

The fact that the person is being asked to take the test is a pretty good indication that investigators think there's something there. The suspicion caused the interview and the interview caused the admission. There's no way to know what happens in an alternate universe with no polygraph. I worry a lot more about law enforcement that use it as justification for their erroneous suspicion.

It's a fine tool as long as the interviewer doesn't think it actually works. I've seen enough police interviews on TV shows to know that many of them are believers.


Police interviews on scripted TV copoganda dramas, or fly on the wall 'reality' police TV shows?

Either way a great many police are believers in the power of theatre. As they should be, staging power imbalnce, inserting faux sympathy, etc. are all powerful tools with strong potential for misuse which has prompted regulation in a number of countries demanding full recording of interactions with suspects.

Speaking of police interviews on TV shows:

  Opening scene to Season 5 of The Wire.
  Classic moment where a copy machine is used for a lie detector. 
https://www.youtube.com/watch?v=DgrO_rAaiq0


I'm not talking about fiction, I'm talking about interviews with detectives on a show like 20/20.

The way they talk about both people refusing to take the polygraph and whether they pass or fail belies a belif in their credibility. I also know some police personally who speak in the same way but that's a much smaller sample size.


This is still subjective feels.

I absolutely believe that some police detectives have real genuine faith in polygraphs being accurate. I strongly suspect a good many do not.

That's orthoganal to how detectives that don't have faith in polygraph results being "real" feel about people that refuse to take them.

Many may feel that people that refuse tests that supposedly tell truth telling from lying can be ranked with people that refuse a search or to unlock their phones ... ie. that's a sign that that they very probably have something to hide.

> I'm talking about interviews with detectives on a show like 20/20.

These are professionals being interviewed who are projecting all manner of things, if they don't actually trust that polygraphs work as scientifically accurate tests that reliably detect lies they are still motivated to not say so and to project belief, that's all part of the theatre of manipulating suspects.


> These are professionals being interviewed

They're detectives from the case. They aren't interviewing the same guy over and over, it's a different guy for every case. And, like I said, I've known a few personally who echo the same thing.

Never once have I seen it presented as an interview technique. They will "clear" people based on polygraph.

This could all be theater, as you're saying, but we're getting into 9/11 size conspiracies to keep all of this coordinated. It's much more likely they are telling the truth. If only there was a machine we could hook them up to to find out...

> Many may feel that people ... that's a sign that that they very probably have something to hide.

That's another can of worms.


That's a very peculiar non-sequitur to pick.

Plus, finding "clues" could mean anything, including false leads. If the Shin Bet is resorting to interviews under duress, they really must not have much physical evidence to work with.


This is standard procedure for everyone in certain roles. Presumably for the same reasons the FBI does this.


That is one of the most surprising aspect of the story for me, that a polygraph worked. (the revelation itself just confirmed what everyone already suspected).

My theory is that the new head of the Shin Bet who is pretty right wing and took a personal interest in the story was involved. They simply used the polygraph results as an excuse to direct the interview in the direction they wanted. The timing is certainly very interesting.

It's a very high profile case so i guess the truth of the matter will eventually emerge.


A polygraph test consists of two components: a bullshit machine, and an interview.

The interview is the part that exposed those clues.

The thing about pseudoscience is that it will sometimes appear to “work.” A dowser will sometimes find water. A horoscope will sometimes predict your day. My birthmark has successfully warded off tiger attacks for 40+ years.


No, polygraphs are bad lie detectors/truth detectors.

They are perfectly fine as detectors of areas of interest for investigators to probe deeper.


Yes or to pressure you into confessing, honestly good interrogators can do this without the machinery.


Good carpenters can build stuff without nail guns, doesn’t mean it makes sense to use hammers.


Carpenters use hammers all the time…


Uh yeah… just like investigators use tools other than polygraphs.

The point is that just because something can be done without a specific tool does not mean you should never use the tool.

I guess I should’ve added “doesn’t mean it makes sense to use hammers exclusively" for the HN pedants.


No, because I would never talk to them.


Unless you just never talk to anyone, how can you be sure you'd know?


Nonetheless waiving the theater for Bongino et. al. implies that Patel thinks the theater works, or at least that these guys were likely to fail anyway regardless of "many issues". It smells corrupt, like everything else in this administration. And IMHO that's more important than a technical critique of a particular interrogation method.


The main point of the screening is to have a highly structured question and answer session that is recorded for posterity, and which can/will be referenced at the next screening 'n' number of years later.

One could even argue that the polygraph benefits the person being screened, as it provides some additional motivation for them to take it seriously.


The FBI and CIA have polygraphs.

The FBI and CIA still have moles and they often times operate out of the highest levels.

They're like door locks. They keep honest people honest. They provide zero security.


Door locks are a deterrent that increase the difficulty and cost of a crime. If your neighbor's house is locked and yours isn't, then you're going to be more of a target. In that sense they do provide security, but of course any lock might still be defeated.

Similarly, I can see how structured psychological interrogation, assisted by a polygraph, is a useful deterrent. The presence of moles doesn't negate all of its value. Just like having your house broken into once doesn't mean you'll stop using door locks.


The difference is that locks actually do work. They’re not merely a psychological trick, they actually do provide a barrier, even if one that might not be hard to defeat.

Considering polygraphs don’t work at all, I have to imagine that an equally effective interrogation could be constructed without them.




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