Hacker News new | past | comments | ask | show | jobs | submit login
Accused spy Alexander Yuk Ching Ma evidently beat the polygraph (antipolygraph.org)
154 points by giles_corey on Aug 18, 2020 | hide | past | favorite | 186 comments



The polygraph is pseudoscience. Of course it can be beaten, it doesn't work to begin with.

Why the US still puts so much weight on them when they know they don't work is a mystery to me. Just get rid of the damn things and do your homework better.


I think its a way to get people to admit to things. Like even knowing they don't work, it's stressful to be strapped into that chair, and even knowing the technician is probably lying when they say they're detecting deception on a particular question, it's stressful when they accuse you of lying. I bet a lot of people crack and admit to things they were hoping to hide.

The trouble comes from the fact that in order for all of this to work, you need to say the polygraph works. If you admit it's fake, or even if your procedures imply it's fake, it loses its magic. And so you naturally develop procedures that put a lot of stock in the polygraph. People start to believe in it. You build up a culture that relies on the magic of the polygraph. And then things like this happen.


>I think its a way to get people to admit to things

This is the standard way human discourse happens when talking about something for which there is no evidence of efficacy. You back up and try to rationalize some other reason for it's use, even when it makes no sense. Like in this case, using it to get people to admit things, can lead to false confessions or false convictions, especially when some of the people you threaten to use it on know it doesn't work! Do you think the agent who knows it doesn't work, and just uses it as a threat, is going to drop the case when you take the polygraph and fail? Nope!

It remind me very much of when people discuss some supplement that doesn't have evidence: "Oh well those studies didn't use enough/too much/wrong schedule" or acupuncture : "oh well even if it doesn't work the placebo effect is valuable"

you just can't get through to people


Yeah, I bet it elicits a whole lot of false confessions. But I also suspect that intelligence agencies are perfectly happy to incorrectly reject a significant portion of applicants if they think it increases the number of malicious applicants they manage to reject. Like they only care about having high recall for detecting spies, even if they have terrible precision.

I'm not saying that makes for an actually effective system. I think it probably does more harm than good in that it leads to people thinking "well this guy passed the polygraph, so I can definitely trust him".

And of course, the calculus is totally different in criminal proceedings, where we absolutely should not be willing to make that recall-precision trade. I can at least understand why someone would think they're a helpful tool for counterintelligence screening, but any use in criminal investigations just strikes me as ludicrous.


But it is a placebo. That's the point of it. They know it's a placebo. If it works as a placebo, then they have no reason to stop using it. The question to ask is: does it work as a placebo? At all? Ever? If it has successfully worked as a placebo in even one instance, then it should probably be continued to be used as a hiring requirement for intelligence agencies (and for no other purpose by any other entity), in my opinion. As the other replier said, it's a deliberate trade-off of high sensitivity and low precision.

I think the parent poster is 100% right. The whole conceit of an intelligence agency is deceit. The placebo effect is probably responsible for a big portion of their overall power, in a lot of different ways, and it makes sense they'd utilize it when hiring people. The only danger is using it in any other setting, or if the examiners or people who rely on it somehow start believing the placebo isn't actually a placebo.


Polygraphs are not used in interrogation (where "interrogation" is "interaction done with a suspect with the goal of obtaining a confession", and "a confession" is "the suspect's own testimony, that gets written down and replayed in court.") All evidence obtained through a polygraph is inadmissible in court, so it's actively counterproductive to use a polygraph if you want a confession. (IIRC, if someone does confess under a polygraph, you need to take the polygraph away, let them calm down, and then ask them to confess again.)

Polygraphs are used for two investigative purposes:

1. To attain leads for investigation. This is basically tool-assisted https://en.wikipedia.org/wiki/Cold_reading. You take a person, add some probative questions, see what makes them nervous, and then dig in further on those topics. Nothing they say can be used as proof of anything, but it can sure guide you to go have a closer look in their bag/at their ID documents (TSA); or to ask the friend they mentioned to come in as a witness; or to try to get a warrant to search their vacation home. (The statements made under polygraph aren't admissible to get you the warrant, either, so you'd need to find some other probative evidence before doing that last one. Usually this is when police would start stalking someone to obtain a DNA sample from a gum wrapper.)

2. To eliminate potential suspects (or potential witnesses!) when your pool of People of Interest is huge (e.g. when a murder occurred in public in Times Square.) A polygraph is a very weak form of exculpatory evidence: it allows you to say that some people are just less suspicious than others, without letting stereotypes guide you in that judgement. If you have 400 PoI and you need to decide who to look into first, batching them through a five-minute polygraph session is an easy heuristic for ranking them (especially when combined with other ranking factors, e.g. a criminal-record check.) It's also pretty good at weeding out "witnesses" who didn't really see anything but just like attention.

Polygraph findings can't really be "wrong" in the #1 use-case. At worst, a polygraph-obtained lead will be zero-information noise, and you'll waste time investigating it. But a polygraph used this way will never cause the wrong person to be arrested/convicted.

Polygraphs can be wrong in the #2 use-case, but only in the sense that they might cause an investigation to be derailed for months/years because someone was eliminated early when they shouldn't have been. (This is why it's important to enforce the idea that it's weakly exculpatory: i.e. polygraph findings can be used to rank the "interest" of your Persons of Interest, but not to entirely eliminate them from the PoI pool.)

Where you see polygraphs really "go wrong" is not per se a failing of the polygraph itself at all, but rather it's the common failing of all police investigation: the wrong-headed thinking that you can convict someone by playing Guess Who, i.e. that if you eliminate all but one person, then that person has to be guilty (and then doing a bunch of motivated reasoning to build weak circumstantial evidence into a case against them.) Polygraphs are often used as one of the tools of this wrong-headed pursuit, allowing a biased investigator to justify a winnowing-down of a PoI pool to just the person or set of persons they personally believe are guilty.

But you don't fix that by taking the polygraph away. You fix that by firing those people.


> I bet a lot of people crack and admit to things they were hoping to hide.

I bet a lot of people also crack and admit to things they never did. You're essentially using the stress associated with the "magic" of the polygraph to coerce a confession.


I've told this story in more depth in other places on this site - The one time in my life I have ever been accused of a crime was when the greenhouse I was working at was robbed. I went to the side of the greenhouse to fix a hole, and while I was gone, a lovely gentlemen decided to empty the cash register.

Flash forward to three police statements and one polygraph later.

My experience with polygraph tests is they are a way for police to coerce a confession. I "failed" the polygraph test, and "should come clean now so they would go easy on me." The problem is, I didn't do it, I didn't know who did it, and I didn't want to know who did it. I was 17, and they had no leads. Just an absolute joke.


Sounds like they hit you with the Reid technique.

https://en.wikipedia.org/wiki/Reid_technique


I think the use of a polygraph in a situation like that is disgusting, but I also think it's very different compared to making it a requirement to work for FBI/CIA/NSA.


it's stressful to be strapped into that chair, and even knowing the technician is probably lying when they say they're detecting deception on a particular question, it's stressful when they accuse you of lying

This is a bug not a feature, if everyone strapped to it are stressed out there's nothing for even a trained interrogator to read. Everyone is going to look like they're lying.


I suspect it works on many different levels and that the general stress everyone feels from it is one of those levels.

But in terms of the base "object level" of the actual graphing of multiple biometrics, the theoretical idea is to construct a baseline within the confines of the test, not between you inside and outside of the test. They let you settle in, ask you questions they know the answer to, and compare measurements during known truthful responses to measurements during or near other responses. So they're (theoretically) accounting for the added stress in the baseline.

Obviously this object-level portion of detecting honesty vs. deceit via comparison with a baseline of physiological characteristics is pseudoscientific and extremely unreliable, but it's part of the overall mind game. And even though it's pseudoscientific, it's also not like it's palm reading or something. This sounds a bit ridiculous to say, but pseudoscience is a spectrum. (For example, astrology is more pseudoscientific than MBTI.) If someone has totally normal responses to every question but a bizarrely elevated response to one single seemingly harmless question which no one else has an unusual response to, then that's something to look into and prod. So the object level of it can offer some utility.


I remember seeing it used as an interrogation technique on the murderer Chris Watts. The investigators basically acted all friendly and helpful at first and said this polygraph is just standard procedure. Then afterwards they left the room to "check the results", and on returning accused him of lying. He confessed during the same interview. Hard to say whether the polygraph helped at all, but it shows that it is sometimes used as an interrogation tactic.


This is pretty accurate. There are a couple more interesting elements to it as well (at least in the security clearance side of things, and not "criminal proceedings" side):

1. there is a lot of stress around the fact that if you don't pass the poly, you don't have a clearance and so you don't have a career

2. you will "fail" at least one poly in each cycle so the stakes are raised in subsequent interviews RE: #1


Ahh... the placebo effect[1]

[1] https://en.wikipedia.org/wiki/Placebo


Let us never forget this infamous explosives 'detector':

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

Sold to law enforcement in military around the world for a while.


It actually makes sense for law enforcement even knowing the device does nothing because it can be used to give them probable cause to search somewhere they wouldn't otherwise legally be able to search. When the shit hits the fan the company that sold it takes the fall, which is part of what the police were paying for.

Perhaps a similar logic is at work for the military, but one would think they'd be more concerned with actual efficacy of such a device so it seems more likely it was just collusion between purchasers and sellers to siphon tax money.


Just like those dogs that indicate the presence of drugs. Except of course when there aren't any. I've had my car searched a couple of times at the Canadian/American border because a dog gave a signal. Given the number of times I've crossed that border the false positive rate must be ridiculously high.

Since you don't have much in terms of rights when crossing a border I wondered why they even bother with the pretext. I'm about as anti-drugs as you'll find and if those dogs are responding to my car then they'll respond to any car.


US LEOs are big on traffic stops + delay tactics to buy time to have the drug dog arrive and sniff a car. Back when the show "Live PD" was on it was used heavily and officer calling a "hit" on the dog in some areas sometimes seemed like a stretch.

Coworker of mine was a sheriff deputy in Indiana and he confirmed this was a common practice.


> Since you don't have much in terms of rights when crossing a border I wondered why they even bother with the pretext.

To find other "bycatch" - cash to confiscate, for example, or the gun that might be forgotten after the last hunting ride, or a pack of medicine without a prescription.

In the end it's a game of probability - assume that out of 1000 cars 1% (10 cars) have something that's not an illegal drug, but still illegal. Now, police are usually banned from warrant-less searches of vehicles for a good reason, so assuming they would follow their own rules, they would possibly only search the one car of the dude with red eyes, and the other potential hits would be missed.

Now, with a "trained dog", they have the legal authority to conduct a warrant-less search - which in turn enables more insidious stuff such as racial profiling the drivers, or simply do a rough check of all cars.

"Drug dogs" are nothing more than an instrument of abuse.


Can't they search for those anyway? It is the pretext that I don't get. You can't refuse the search. So just get it over with and leave the dog out of it.


No they actually can’t in most cases. Without probable cause or permission, an officer is not allowed to execute a search. The dog is used to provide probable cause.

Also, it’s the same with letting an officer into your dwelling: Without a warrant, probable cause, or permission, they cannot legally enter.


No, while crossing the boarder you can be searched without a warrant, permission, or probable cause


Also at the border? I thought customs had a full right to inspect whatever they want there.


Oh wow! I've never even considered that. I wonder if the dogs pick up on subtle behavior cues from their handlers, which the handler may not even be aware of. The dog ends up giving a seemingly legit outlet for some unconscious bias.



An officer can give the dog a subtle cue to alert. Happens all the time.


All they have to do is say “I smelled weed.”


I also think there's value in tools that allow our subconscious to override our conscious mind when it comes to making tricky decisions. (But never in support of probable cause.)

I'm reminded of the chick sexing story from a while back. About how no one can tell you what to look for to separate male from female chicks. But you can still learn how to do it through trial and error.

A device that basically tells your conscious mind to pause requires that you believe the device is working.

Even better would be training people to deliberately allow their subconscious to make certain decisions.


I don't think the subconscious mind is able to 'make certain decisions', it operates on a whole different level than the conscious mind. But that's a discussion for another time.


Here's the article:

https://psmag.com/magazine/the-lucrative-art-of-chicken-sexi...

Yeah, subconscious decision making is probably the wrong term. "Instinctual" decision making?


Someone I knew involved in defense procurement explained the proliferation of such devices. Basically these small companies who make these things will hound politicians saying they've got a device that can save soldiers/police lives but your bureaucrats who handle supply chain sourcing and testing are slowing us down - please help us accelerate this and we can save lives. They'll usually bring up that this is a small company who is competing with the military industrial complex keeping them out of the game. This usually results in one or multiple politicians pressuring the applicable agency, to the point where they'll threaten to withhold funding to consider a trial or small purchase. Fast forward a year and these devices are deployed and thrown away due to the fact they obviously don't work. It's worse in the law enforcement circles where they actually believe the stuff until a court gets involved and things get thrown out and guidance is given to drop the crap.


While I totally agree with you, I... have a theory.

It might be psychological warfare.

I would wager that a surprisingly large number of people think that polygraphs detect lies. An even larger number are probably open to the possibility.

If you hook up somebody in that group to a polygraph, you probably rocket their stress levels through the ceiling, which might push them to crack. Behavior under stress is a fascinating thing.

Honestly, I had a snarky comment ready for a comment lower-down about the rationale for polygraphs, but I thought about it a bit, and can't, off the top of my head, come up with a faster, cheaper, and safer way to put that kind of stress on a person.

Useless against somebody trained -- like, say, an intelligence operative -- but it might not be as stupid as it appears on the surface.


The Wire has a great scene where they use a photocopier as a fake polygraph to crack a suspect.



I thought this was quite well accepted. I can't speak to the FBI, but for CSIS, the Canadian Equivalent, the "polygraph tech" who pretends to just be working the machine, is actually a psychologist watching your responses.


What's Ironic is some of these agencies that require them for classified information, also teach field operators to evade them. The other fun part about them is when you're in an unclassified situation getting a poly and they're asking questions that if you answer you divulge secrets, if you don't you're lying.

I was once told that I was too calm for my poly and then asked why. My response was I didn't trust the science, or the fact that it was a couple week course. That didn't go over well, I ended up taking two more after that and they gave up.

I've seen the other-side of it though where good people failed their poly because they had too low a baseline like I did, caused by medications.

It's really a bunk science. I can get it as a scare tactic, but the fact the the Govt. still relies on it at a higher level is ridiculous.


> who pretends to just be working the machine, is actually a psychologist watching your responses.

Maybe that's true in Canada (don't know) but it doesn't matter because psychologists are no better at detecting lies than a typical person of similar education, intelligence and age.


The issue is accuracy. In terms of being able to infer lies from skin response, this is an effect that actually exists for many people. The net scientific conclusion is that can work but poorly, not that is is complete nonsense like ESP or something.

Being pseudoscience or not is not quite the same question. People claim acupuncture works for them (California is now forcing insurance to pay for it), but it is clearly based on pseudoscience.


What are the chances of an actual spy being able to beat a lie detector?

I'd put those at about 100%. So you will end up with nervous people who will increase the size of the haystack with zero chance of identifying the needles, which is a net negative.


> What are the chances of an actual spy being able to beat a lie detector?

I'd say not even remotely close to 100%. What is an "actual spy"? Those people are often regular employees with zero relevant training, that are simply recruited by a foreign intelligence agency via pressure, money, or manipulation, and are targeted based on their access to information. I'd say that a huge percentage of them won't be able to beat a lie detector.

Secondly, polygraph tests are used for a lot more than weeding out actual spies.


What you are referring to are embedded assets. Embedded assets are different than trained spies in intel or counter intel. A trained spy may be a handler of assets but they generally do intel work themselves and usually have some form of cover. A trained agency spy will undoubtedly be able to beat a poly and are trained to do so, on a regular basis. While the accuracy of a poly is too low to be usable for the discerning of truth, they do work to some degree. They are better at telling what you said was true than they are at telling what you said was a lie. So generally if a question is asked and you don't pop then it is fairly safe to assume that you told the truth. Where their completely fail, is sometimes they will pop when you are telling the truth and you can train yourself to not set off the machine when you lie. The problem is it works on the right kind of person in a clean room setting, but that is never the real world, there are just too many variables that are not handled for it to be anything other than a psychops tool, where it just becomes a loose guide on where to dig deeper.

Fun fact, lie detectors are completely ineffective on compulsive liars.


In everyday colloquial use, the term "spy" applies to what you are calling "embedded assets", whereas the term "trained spy" isn't used professionally at all. A "handler of assets" is a case officer. An intelligence agency employee who "does intel work" in the field might be a paramilitary officer, or some other name depending on the agency.

In the context of this thread, Alexander Yuk Chung is definitely not what you are calling "a trained spy", but an asset that was recruited by Chinese intelligence almost 20 years after joining the CIA. Like I said - there is no reason to believe that most of those would be have any sort of training relevant to passing polygraph tests.


I work in counter-intel, I am well versed on what we actually use, assets are not "spies" and to get technical about it nobody is actually called a spy. But generally a "Spy" as is commonly depicted, denotes someone with governmental or diplomatic cover, an asset is an independent citizen that provides Intel usually a national of the country in which Intel is being gathered on, and generally has no cover. A case office is not an handler, a field officer is, a case office is an analyst. There is no such thing as a paramilitary officer, their are field officers, special agents and military liaisons. <- all of the above mentioned with the exception of analyst and assets would have formal training in evasion, which would include how to flatten a lie detector.


As I said - assets are routinely called "spies" in colloquial use and in the media, as is evident even in the story that this post links to, as well as countless other media references.

> A case office is not an handler, a field officer is, a case office is an analyst.

This is incorrect, as is evident by a basic google search. An analyst is -- surprise -- called an analyst.

> There is no such thing as a paramilitary officer, their are field officers

This is also completely incorrect. CIA SAC/SAD operatives are called paramilitary officers. The official CIA designation is Paramilitary Operations Officer.

You might have encountered different definitions in your work or private life, but they are not representative of how those terms are commonly used, both colloquially and in common professional contexts.

Beyond that - your replies add nothing to the discussion. The precise definitions and terms change from agency to agency, and from country to country, and are irrelevant to the original point being made.


Can confirm. There certainly are paramil officers and in the roughly exact way you put them. Parent was apparently on some other program, or in some other compartment for whatever reason, but here's another voice who does confirm. If it didn't exist then wtf were we in on? It seems to have existed pretty great; i buy the same pairs of Keens i wore over there. I swear to the Keen shoe brand since they are basically 'worn in' from the start. Apart from that I look civil though. Not a protese in sight. Support your local decreeped person, either physically or mentally.


I'll say it again: they don't work.

You can't really use them for anything. A polygraph machine might have an application though: doorstop.


That's possible, but your previous comment is still incorrect.


I'm not advocating their use. Just arguing for a less politically-motivated description of a technology's accuracy.


Astrology, Tarot, and Fortune Telling are all pseudoscience, but a good practitioner is going to be very good at Cold Reading.

http://skepdic.com/coldread.html

It works as long as the "mark" is naive. As James Randi explained many times.

Which is why intelligence communities want to suppress information about polygraphs that would make people less naive.

Makes perfect sense.


Being good at cold reading does not mean you can actually predict the future, which is what they are claiming to do. But if they could do so with sufficiently high accuracy to accomplish something useful, then this would still be interesting.

And frankly I think the "pseudoscience" label for lie detectors is a stretch. It measures a genuine signal. The issue is the relation of this signal with lying. They do a lot of strategy in their question selection to try and make this relation hold. And to me (trained in actual science) it makes a decent degree of sense. If it fails to deliver due to there being way too many variables and noise, so be it. But it's not magic or something like psychics. There is legitimate research related to determining emotion with various types of sensors. https://scholar.google.com/scholar?q=review+wearables+emotio...


You're not wrong, but it's a little rich that a site full of programmers, of all professions, can't understand why an interview procedure exists even though everyone knows it's bullshit: done any whiteboard coding questions recently?

Even if everyone knows it's crap, it can persist because of institutional inertia and because no one has come up with anything better. That's what happened to us, so we shouldn't be surprised to see it elsewhere.


I agree it should never, ever be used in any capacity when it comes to criminal proceedings, but as an employment requirement, I think the 3-letter agencies should keep them, and I suspect they will unless/until they perhaps obtain some literal mind-reading technology.

It's a psychological tactic, and is all about pressure. It serves as a potential deterrent and mind game that works on multiple levels. Consider it like a scarecrow in a field. Yeah, some of the smart crows will figure out it's just some clothes on a pole, but it still deters and confuses the rest. The only silly thing would be calling a scarecrow a security guard or a polygraph a lie detector test. It doesn't mean it's silly to put a scarecrow in your field.

Obviously it's 99.9% pseudoscience, and obviously it's beatable and unreliable, but I don't think that's the point. I'm sure they're very much aware of that, and still use it because they see the value of it as a psychological tactic. It's one of many lines of defense: if you pass that line of defense, it definitely doesn't at all imply you're not a spy, but if you don't pass it (in any way), the security requirements dictate that the safest option is for them to not hire you.

Absolutely no positive value should be attributed to a passing result. The idea is exclusively to attribute negative value to a failing result. And then, not value in terms of some actual empirical finding ("was this person really being deceitful?"), but just value in terms of whether or not to hire them to handle the most sensitive of secrets.

The only abomination is using it as a consequential determination of truth or lie, or innocence or guilt, like in a police investigation or trial. It should never be permitted in such a circumstance for any reason.


Well, good luck with that. Any employer that wants me to submit to a polygraph test will have to do without me. It's beyond ridiculous that this is permitted at all.


I don't think any employer should require or request them besides the 3-letter agencies, to be clear. (I've edited my post to clarify that.) I agree it would be completely absurd for any other organization to require them, and I would never apply for a job with such a company or ever accept such a test; but I'm not someone who wants to work in intelligence or national security.

If you want to work in intelligence or national security, I think that's just one of the things you have to accept, along with being investigated and monitored and surveilled and all that. You know what you're getting into when you apply for such a job. I similarly wouldn't apply for any job that requires my employer to ask all my friends and family about my character and habits.


Yep, you can 'accidentally' beat it with decent probability.


Esp. w/ someone who has the constitution of a secret agent, who is literally trained to lead a secret life. If they can't fool a device like this how can they be expected to fool high-level operatives in their adversary's intelligence agencies for decades on end?


> Why the US still puts so much weight on them when they know they don't work is a mystery to me.

Because for a lot this lets you continue whatever spectre of activism they are pursuing. Remember the Justice Kavannaugh sage and his accusers taking polygraph tests?


Reminds me of this scene from The Wire

(NSFW) https://www.youtube.com/watch?v=AJ5aIvjNgao


It's a bit of a joke, really. I doubt there's anyone reading this on here who didn't already know polygraphs don't work. The only people who don't seem to know polygraphs don't work are the ones making national security decisions relating to polygraphs.


The polygraph process is not a technical one, but a psychological one. The point is not to detect a lie by "registering it" on the tool, its to create a situation where a person self-elects information because they believe the machine _could_ detect a lie. Its a huge dog-and-pony show, and the poly operators play it as a big game.

So, polys _do_ sort of work, but not in the way they are presented to the public.


My guess is that this works just like how it does in corporate security: It is vastly easier to add a new security policy than it is to remove it. Even when everyone knows something is useless or perhaps even harmful, nobody wants to be in a position to be held culpable on the off chance that retiring the policy is implicated in a future breach.


Polygraphs are a $2 billion industry, and Upton Sinclair said it best: "It is difficult to get a man to understand something, when his salary depends on his not understanding it."


Sure, but what about the people buying polygraphs?


Their jobs depend on the polygraph existing as a credible institution


The trope that they are meaningful continues on shows like "Dateline" where local cops drop "persons of interest" after "passing" one. And insinuate that someone that refuses one is guilty, etc. It's really odd to me that the general public has no idea that polygraphs are complete bullshit.


let's get real, polygraphs are a ruse in order to humiliate people and see how they react in torture situations. Using them is a power play. It lets the victim know who the boss is.


Polygraphs are there to create a high-stakes stress/interrogation situation to see if someone cracks or reacts. It's more of an art form than a science -- and that's why it's not admissible as evidence in a criminal investigation (and shouldn't be)

The rationale for continued use in clearance screenings is that it's not scientific, but it's better than nothing.


I don't think it is better than nothing at all. Passing a polygraph test is now potentially a false signal, giving a false sense of security to the parties concerned. Without a signal the situation would be better.


Partly its that. Partly its about tricking juries, "He failed/refused the polygraph" is a very nice way to discredit someone. At least 5 of the 12 people there will find that concerning and not know its BS.


Any lawyers in the house? I was under the impression that (in the US) refusing to take a polygraph was not considered an admission of guilt though could be grounds for dismissal from federal employment.


What's legal has nothing to do with swaying a jury.


If the opposing side brought up refusing to take a polygraph you would object and ask the judge to explain to the jury why that had to be disregarded, right?


I doubt that any judge would allow that to even be brought up in a trial. If it were, it would probably be an appealable issue that would get the case thrown out.


I thought polygraphs are prohibited in courts in most jurisdictions?


It's used in criminal courts 19 states and at the federal level by the disgression of the judge. Plus it's used in a bunch of "non-court but legal process" like for people on probation.

https://en.wikipedia.org/wiki/Polygraph#United_States

Interestingly (last paragraph of the link above) the US has indicted people for offering to teach other how to beat the test!?


This seems like a pretty adversarial way to look at it, using words like "power play" and "victim." From my understanding the CIA still regularly uses polygraphs. I have to wonder why that is, and it may have nothing to do with the polygraph itself. Maybe it's more just making sure someone has nothing to hide? I'm also not sure what "beating" the polygraph means in the context of them not working in the first place. How do you beat something that doesn't do what it purports to do?


I've talked to someone who administers polygraphs, and they said the machine is mostly theatre, but that there is normally someone watching you through a hidden camera or double sided mirror to see how you act when you think someone isn't looking. For example, when I had to take a polygraph for work, the polygrapher left the room a few times because they "needed to get a second opinion about abnormal results". That's when the hidden person would supposedly be watching to see if I acted differently when I thought I was alone.


That process sounds even more scientifically dubious than the demonstrably dubious machine.


Indeed, but no more so than any interview process. Perhaps they should use a whiteboard instead?


right, when left alone the subject started flipping a coin (one side of which was disfigured) manically, and seeming to have an argument with themselves, sometimes shouting "you're guilty, you know it" and other times growling "those coppers will never crack me".


Beating the polygraph means passing it when you're lying about the relevant issues. Although polygraphy has no scientific basis, the methodology employed makes effective countermeasures possible.


I'm not sure how stupid a spy would have to be for "are you a spy? Be honest!" questions to work. But if I were running an organisation I suppose I'd have people ask anyway because it'll catch some idiot sooner or later.

Polygraphs as a power play - well, I'm sure it happens but that probably isn't the reason it is in the room. Maybe the polygraph is a ruse to make people think FBI questioners are stupider than they really are? I can see value in having a distraction from the actual questions.


> I'm not sure how stupid a spy would have to be for "are you a spy? Be honest!" questions to work. But if I were running an organisation I suppose I'd have people ask anyway because it'll catch some idiot sooner or later.

Those are questions on the SF-86. Ditto for a lot of customs & immigration paperwork. "Idiot detector" questions.

But if you don't have them on there then they can claim "but you never asked".


Yep, it's also another line item when charges are brought. Kind of similar to how states like Tennessee that don't have legalized marijuana still have a tax stamp process. I doubt anyone ever applied for one, but if you get caught with some pot, boom pot and failure to present tax stamp. Two for one.


Ah yes, polygraphs, long proven nonsense and not used in virtually any other western country. I wonder how he beat that?


Aren't they essentially just glorified galvanometers like the Scientology e-meter?


Yes, and I built a very simple one in law school, to illustrate the concept (well to be honest I was an engineer who went to law school as a hobby, and then I took every excuse I could find to build technology things as a hobby within a hobby). Anyway it was just a multimeter, some washers soldered to copper wire and some tape to keep the washers in their place on the subject's hands. When people didn't try to game it, it actually sort of worked, although I have no proof of statistical significance; I just had a feeling of 'better than random'. (our experiments were more focused on how to ask questions to elicit the highest response, as questioning with a polygraph requires some skill at asking questions that are leading or not, and in just the right ways).

Conclusion is still that it's nowhere near reliable enough to be used for anything, but the principle that people show physiological responses when answering truthfully or not about things is sort of true (I don't think that was ever under debate, still was a fun experiment).


Just a guess, but I wonder if a polygraph is useful as an intimidation tactic? Maybe you can't detect lies with any sort of accuracy but you can intimidate people into making more mistake when answering questions and that can be used to figure out if someone is lying? OR perhaps they can pressure some people into revealing more information than they otherwise would?


Yes that's how it's used. That depends on people believing polygraphs work though, which is why polygraph companies for decades have been litigating against people who question polygraphs. Sometimes just the idea that there will be a polygraph test is enough to get people to be more truthful. It's like placebo drugs - if it works somehow, should we care about whether it actually works? By that reasoning, should we allow homeopathic drugs for healthcare insurance reimbursements? If Josie doesn't have a headache after taking pills, does it matter whether those pills are paracetamol or water with a story of it being very potent water? Fun discussions, not very productive, but still fun (for a while).


"That depends on people believing polygraphs work though"

Are you sure that's true? In medicine, apparently placebos have an effect even if you know that it's a placebo. I imagine that even if you know that it's theoretically useless, being hooked up to a machine that can read your vitals while lying would still be nerve wracking.


Having an effect is different from being able to sell a product based on that effect. For regulated fields like pharmacy, the FDA regulatory approval test requires proving efficacy against a placebo. A doctor may (under certain specific circumstances) treat a patient using a placebo (because medicine's aim is to do whatever that is necessary to alleviate the problem or reduce suffering, it is different from pure biological natural sciences/pharmacy where inferences must be backed up by scientific theory and validated by empirical evidence) but it does not necessarily mean that a placebo can be sold/marketed as a cure.


To a degree of course, just 'but it might work' would be enough I guess, the same way someone needs to at least not be told something is a placebo for a double blind study to be "valid" ("methodologically sound" would a better term I think?). I did read quite a lot on the topic and much has been written about it over the years, but this was 10+ years ago for me, I don't remember enough to really make a coherent argument that addresses the details.


Pretty much. They also do heart beat and a bunch of other things. Then (like a scientologist) the operator "interprets" that you're lying or not.


There was a tv show in the uk where they used them to prove/disprove infidelity - I think it caused people to actually break up.


On the Jeremy Kyle show, the lie detector drove one guest to suicide (which led to the show's cancellation):

https://www.telegraph.co.uk/news/2019/05/22/jeremy-kyle-gues...


The show (Jeremy kyle) was taken off air because someone who failed the polygraph committed suicide.

https://www.telegraph.co.uk/news/2019/05/13/jeremy-kyle-take...


I'd guess that polygraph tests need belief into them working, thus making it work. Polygraphs should be able to (at least) measure nervousness correctly (e.g. due to transpiration), so if you believe polygraphs may work you're probably someone on which they will work (1).

In other words, long proven nonsense as long as you don't believe in it.

(1) https://antipolygraph.org/lie-behind-the-lie-detector.pdf (Chapter 3)


You're wrong, they do not magically start working if you believe in them. If you're nervous for ANY reason it will give off a false positive. Not only if you're nervous of the machine itself.

It is insane it's still being used in the US.


In former CIA officer Valery Plame's book Fair Game, she describes how an old hand at CIA told her that the best way to get through the polygraph is to be as detailed and honest as possible. Even on subjects that would be embarrassing, merely focussing on describing the truth and knowing that the interviewers appreciate candor can often alleviate nervousness.

I've never been polygraphed and I have conflicting views on it, but I suspect if I were ever in the same situation I'd do the same thing. They may not work perfectly, but they are a forcing function to the interviewee. Are you going to tell the whole truth in all its messy detail or not?

That said, I don't think they belong in the justice system. Someone who is already accused of a crime has to choose between either doing a polygraph and being potentially being nervous because their freedom is at stake, or denying the polygraph and looking guilty.


If I remember correctly, note this is contrary to the advice the antipolygraph sites gives. They state anything the person interviewed admits, no matter how trivial, will be used against them (e.g. "have you ever smoked pot in college?"). That the "good cop" of the interrogation is always a ruse; and that since polygraphs don't actually work, small "admissions" are a big part of the actual information gathering... including the questions that are allegedly for "calibration".


No, they don't belong anywhere. They are still useless.


One of Obama's staff, maybe press secretary said something similar. On NPR she said when they pressed about marijuana use in the screenings, she told them flatly she used it 500+ times.

But like you said, in a legal proceeding they are terrible to use.


Polygraphs are not used in US courts and the results are not admissible at trial, so I'm not sure what you're referring to in the last paragraph.


I think there is confusion/conflation with defendants offering to take a polygraph to prove innocence. Sometimes it’s a naive offer sometimes it’s someone who wants to “show proof” they “didn’t do it”.


Which is part of why they're inadmissible regardless of who wants to use them.


Sure but it’s usually a PR stunt by the defense “see my client is willing (therefore innocent as no liar would take the test the CIA uses to expose moles)”

“We took a privately administered test by a certified polygraph administrator and my client passed with flying colors!!!”


> If you're nervous for ANY reason

Agree, and also agree, it's insane. Still that's the presumed thinking behind it.

The (anti-polygraph-myth) site I linked comes to a similar conclusion.


> You're wrong, they do not magically start working if you believe in them. If you're nervous for ANY reason it will give off a false positive. Not only if you're nervous of the machine itself.

If you're just as nervous during control questions as lies then it would be a false negative. The "tack in shoe" tactic is supposed to make yourself uncomfortable during control questions by stepping on the tack and raising the baseline.


Per the article:

>It is to be noted that around the time Ma applied for employment with the FBI, the Bureau had a roughly 50% polygraph failure rate for special agent applicants, with many honest persons being wrongly branded as liars and barred for life from FBI employment

So either 50% of FBI Applicants were actually foreign agents AND believed in polygraphs (why would they if they were trained foreign agents?) OR it's just total bullshit. I think the "it works if you believe in it and some people do" myth is just that...

It's a very attractive idea that we can tell (even partially) whether someone is lying. We actually might be able to with an fMRI setup I think. But polygraphs should be long gone as rubbish. I have no idea why anyone in the USA takes them seriously.


> So either 50% of FBI Applicants were actually foreign agents AND believed in polygraphs (why would they if they were trained foreign agents?) OR it's just total bullshit. I think the "it works if you believe in it and some people do" myth is just that...

It's even dumber than that. From what I've heard, the big failure rate is often with respect to drugs. You're allowed to have experimented with marijuana a specific, small number of times.


Hypnosis comes to mind :-)


My understanding is polygraphs are used as a tool to have people trip over themselves by using it as a prop when the administrator thinks they have something to catch them on.

Now that makes me wonder, if they don’t use fMRI is it because it’s also just a prop but with more studies behind it?


Exactly. It's just an interrogation technique but you need one less body on the payroll because you don't need a "good cop".

Pretty much every manipulation technique used in negotiation, sales and interrogation is useless if the person it's being applied to realizes it. Polygraphs are about the lowest quality because the machine is right f-ing there for the world to see whereas with other techniques there's at least a non-zero chance that the person using them is being earnest and it's not just a technique.


>Pretty much every manipulation technique used in negotiation, sales and interrogation is useless if the person it's being applied to realizes it.

That is just wholly incorrect. The whole point of marketing is that it works even if you know it's happening to you. Anchoring, a common sales tactic, works even if you know they're doing it to you. You can absolutely respond to it with your own tactics if you know about it, but it still effects you. We really aren't better than our animal brains.


>The whole point of marketing is that it works even if you know it's happening to you.

The point of most advertising is selling an emotion. (Advertising is a subset of marketing) Convincing the buyer to buy a product based on projecting a feeling on or drawing an emotion from that person. This is inherently a lie and thus manipulation. Most people don't realize what's going on.

Let's use Harley Davidson as an example, there are many. Their entire pitch is being a rebel, getting away, being cool, salvaging your youth. It's not, "this is a great machine and good bargain." If most people were wholly objective about purchasing a motorcycle based on utilitarian use and cost, they probably wouldn't purchase a Harley. Advertising to the rescue. It's a brain hack.


What would they buy a 150cc dirt bike?


There are many places where people do buy motorcycles based on utility and cost -- underbones, standards, and scooters between 49 and 250cc are popular. The most popular vehicle in history is the Honda Super Cub.


>You can absolutely respond to it with your own tactics if you know about it, but it still effects you.

Of which ways that it effects a person have you learned?


anecdata: i just rented a house. the listing said x. when i saw the property, the realtor said "rent is ${x+200}". I still felt like i expended my negotiations after clarifying that the rent was actually x. I knew he was fucking with me, but i needed a place to live, and i wanted to negotiate more, but it was hard to muster a negotiation after i felt like I already negotiated.


This is absolutely incorrect. On day one of one of my university courses on negotiation, we did a group exercise that demonstrated anchoring. For those unaware of the concept it's that a final negotiated agreement tends to be strongly influenced by the first position (e.g. price) that is put forward.

After the exercise, we dived into how it worked and how to prepare and counter anchoring. Then we ran a slightly different, but similar, exercise. Even when highly educated students were fully aware of how anchoring worked, and that they were susceptible to it, and knowing ways to ways to counter it, deals still tended to be closer to the initial reference point.

It certainly helps to know ways in which you may be manipulated, but knowledge does not make you immune by any stretch of the imagination.


I read an article somewhere in which a cop told the story of conducting an interrogation using an ersatz lie detector. If he thought the suspect was lying, he'd push a button, and out would come a piece of paper saying "He's lying."

It was a Xerox machine.


That's a scene from The Wire.

https://www.youtube.com/watch?v=DgrO_rAaiq0


The story was around before The Wire.


Yes, in David Simon’s book Homicide: A Year on the Killing Streets, as well as the David Simon series Homicide: Life on the Street.

David Simon also created The Wire.


Fine, it's been around since before David Simon cribbed it:

https://www.snopes.com/fact-check/next-case-on-the-court-col...



This is the opening scene of season 5 of The Wire.


fMRI machines are still quite expensive and require a technician to operate and calibrate. They also require the subject to be sitting/lying still inside the machine while it is being operated in order to get any kind of useful measurements.

Not really sure what the consensus among neuroscientists and psychologists is with regard to weather they are reliable lie detectors or not though.


50 percent chance an honest person barred for life.

50 percent chance a criminal gets let through.

If that’s true it’s a wonder the FBI managed to get this far and continues to function.


Most people applying are not spies. Bayes therom applies.


In a bit skeptical of the 50% number mentioned. I think the newspaper article might be misquoting the source. I know people who have failed lifestyle polygraphs and weren't banned for life, they just had to try again


This is what happens when you rely on junk pseudo-science as a screening mechanism


Many of the water companies in the UK still use divining rods to locate pipes, there's a lot of bollocks used in places that really ought to know better.

Source: https://www.theguardian.com/business/2017/nov/21/uk-water-fi...


What's next? the FBI does palm reading to solve their hardest cases?


No, what’s next is facial recognition and “the computer says with 98% certainty that the defendant’s face is a match, Your Honor.”


Or even "the computer says that the defendant's face is the face of a criminal!"


Taro cards, Runes, or crystal balls would be more apt as you don't need anyone else to be there.

Just call it "AI".



funny you say that https://en.wikipedia.org/wiki/Forensic_dentistry#:~:text=In February 2016%2C the Texas,analysis had no scientific validity.


Handwriting analysis.


Polygraphs are comic book technology. The first one was invented by the guy who created Wonder Woman and they were popularized by a commercial for Gillette razors. It's as ridiculous as determining guilt by batarang or kryptonite. It's amazing we still allow them in law enforcement.


The polygraph was largely invented by William Moulton Marston, the same guy who invented Wonder Woman. It was clearly a farce when he was selling this idea 100 years ago, and it's amazing that it's considered anything short of snake oil today.

There's a great book on the inventor called the Secret History of Wonder Woman: https://www.amazon.com/Secret-History-Wonder-Woman/dp/080417...


KGB did not use or believe in polygraphs. Always found that an interesting comparison to American intelligence.


Does anyone outside the US use or believe in polygraphs?


Yes, unfortunately. The governments of the following countries, among others, rely on polygraphy to varying extents: Canada, UK, Israel, Russia, Ukraine, and China.


China has recently abandoned the use of Polygraph (I read such a news recently).


Aren't there psychoactive meds which weaken control and should work better unless the person has developed resistance against that compound.


There are, the most well known being alcohol.

However, while it makes people more talkative, it doesn't make them more truthful. So it is not considered effective as an interrogation technique.


Alcohol



All the Reliability section of that page says is, there isn't a randomised study you can trust.


And yet in Russia it's used when applying for a job in police.


No private companies hustling polygraph consultants and gear in communist Soviet Union.


Did they use vodka instead?


No, they would just break your fingers or <insert torture> until you admitted to basically anything just to make them stop. They didin't need a polygraph for that, just a hammer, a drawer or a door.


The Panetta review (CIA-internal) and the SSCI torture report (one of those "S"'s are for United States Senate) concluded that torture is largely inefficient at extracting information from extremists. You can torture someone for years on end with them still keeping the things you ask from you. Someone who doesn't know anything, will tell you anything, while someone with deep faith will feed you shit.


It's true, however that didn't matter much in the USSR. What mattered is that somebody got punished, paperwork was taken care of and the agents were doing their jobs. All of this is nicely illustrated in the Citizen X movie, although in a different context.


Citizen X is an American drama. If it depicts what you're saying (I've seen it but can't remember it) then it's just another Western dramatization depicting post-Stalin Soviet Union in cliches from the 1930s.

In the real life case Citizen X is inspired by[0], nobody was tortured for a conviction, even the guilty man, who was simply put into a cell with a police informer to gather information and questioned normally by investigators who only had ten days under Soviet law to release or charge him.

[0] https://en.wikipedia.org/wiki/Andrei_Chikatilo


Post-Stalin Soviet Union clichés, of course. How do you think the wrongly arrested people confessed to the murders in the first place?

"At his trial, Kravchenko retracted his confession and maintained his innocence, stating his confession had been obtained under extreme duress."


> How do you think the wrongly arrested people confessed to the murders in the first place?

As in that example with Kravchenko, the same way false confessions occur in every country, pressure in some form from the police who want to convict their prime suspect / clear up a case.

It's indefensible but it's nothing unique to the Soviet Union and it's not uncommon.

https://theconversation.com/suspects-confess-to-crimes-they-...


That does not make citizen-x documentary. These movies were made from imagination.


Ah, the Guantanamo tourist pack.


No, I think it was the archipelago tour where millions of people got to stay in remote islands but to their dismay never got to leave but they did get to write birthday cards to the steel man.


Plenty of pseudoscience rubbish in law enforcement in the US (and elsewhere):

* lie detectors/polygraphs

* blood splatter patterns

* hair analysis

* bite mark analysis

* criminal profiling



Why doesn’t the CIA just come out and tell all their recruits, we trust you and most of you truly believe in the mission and will never compromise but there are always a group of turncoats who will sell secrets or have other affiliations. Due to this we will monitor your credit and you will not know if the persons you are working with are internal investigators and we will have randomized investigations as matter of course up to the director.

In other words don’t ignore the possibility but work with that limitation.

Maybe they do this and people still do it, if so they’re doing a poor job of it.


From Wikipedia: "A comprehensive 2003 review by the National Academy of Sciences of existing research concluded that there was "little basis for the expectation that a polygraph test could have extremely high accuracy." The cited article: The Polygraph and Lie Detection. National Research Council. 2003. ISBN 978-0-309-26392-4. (https://www.nap.edu/catalog/10420/the-polygraph-and-lie-dete...)


I know we all know that polygraphs don't work, but: is that true in practice or in principle? I mean, there are papers out there about methods capable of extracting complete words from brainwaves. Does it really seem impossible for a machine with current tech to detect signals of lying with high certainty?


It works the other way around: polygraphs need to show that they work in replicated, controlled experiments.

That hasn't happened[1].

Lying is a complex behavior. Like, really complex. Even with all of modern technology, we've only just started to detect far more gross brain functions: pre-speech motor patterns, fear responses, etc.

It goes without saying that an MRI is at least slightly more complicated than something you could knock together in an afternoon after a shopping trip to Radio Shack in 1963.

Polygraphs are a $2 billion industry, and Upton Sinclair said it best: "It is difficult to get a man to understand something, when his salary depends on his not understanding it."

[1] https://en.wikipedia.org/wiki/Polygraph


"I mean, there are papers out there about methods capable of extracting complete words from brainwaves"

As far as I know, this is complete fiction right now. Same with images.

There are people currently working with AI interpreting brain signals to be reproducible, to say, move left and right in a game. It's far from working on "left" / "right", let alone anything more sophisticated than that.


There are researchers using functional MRI (and machine learning presumably) to try and detect lies. There may even be some trying to use it commercially.

I imagine it's about as reproducible as most fmri research, as in not.


I think at some point you might be able to detect lying with high accuracy given a DNA sample, a high resolution/high fps camera pointed at the person's face, and a vocoder-generated questioning regime.

However, it would be very expensive to develop the training data for such a system, and it might not work on rare ethnicities. Or other abnormal people, like autists and evil geniuses.


I think a good liar is just exceptionally good at convincing themselves that what they're saying is the truth. I think that even better liars are so narcissistic that they basically believe what they say as it's coming out of their mouth, on account of it being them that is the one saying it.

I say all of this as a horrible liar.


There are a lot of different ways to lie, and the method you point out is one of many.



Can't these just be beaten with some breath training and a short training in how to answer? All they measure is your physical reaction, right?


You clench you butt cheeks when they do the calibration when you want something to register as a lie. So you tell a truth and then clench your butt cheeks for calibrating a lie. Thus they get a strong response on a truth/lie and a less strong response on a lie. The other trick is to recall a traumatic event.

https://www.mirror.co.uk/news/weird-news/how-cheat-lie-detec...


TIL: my butt is could potentially blow my cover.


and I beat tiger repellent rock(1), and a bomb dousing rod (2)!

1/ https://www.youtube.com/watch?v=fm2W0sq9ddU

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


Are polygraphs still taken seriously?


Polygraphs are a joke for this reason among so many others: Psychopaths, sociopaths and narcissists can fool them because they are able to feel zero (or are incapable of feeling any) biological fear or anxiety (i.e. 'stress response'), while telling complete lies.


Which is a bit horrific when you realize they act as sieves promoting the hire of such people in a higher proportion than the general population. Polygraphs are worse than useless and mere jokes; they are selectors for a kakistocracy amongst the executive levels of American governance!


Realistically, people who have to take them regularly can also learn to do “better” at them, as you can with any “test.”


From my understanding of the article, he was first employed then he started spying, so not necessarily that he beat the polygraph.


He re-applied in 2003-2004, after giving information to MSS.




Guidelines | FAQ | Lists | API | Security | Legal | Apply to YC | Contact

Search: