
How to Beat a Polygraph Test - andrewl
http://www.nytimes.com/2015/04/12/magazine/how-to-beat-a-polygraph-test.html
======
geomark
I once had to take a polygraph to be considered for a security clearance. For
various reason I didn't want it - I didn't want to join the group of social
misfits I knew who worked on classified projects, I didn't want project
security telling me where I could go on vacation and with whom I could
associate (no foreigners), plus I had a few ethical objections. But at the
time I liked my job (lots of great unclassified tech work), wanted to keep it,
and needed to go along with my bosses' desires to get me cleared.

The polygraph was administered by a strange guy from a three letter agency. I
did the sphincter squeeze for every question. He said the test showed I was
being deceptive. I thought that was the end of it and hoped my boss would
leave me alone about it. But they called me back to do another one. This time
I didn't do the sphincter squeeze. He said the test showed I was being
deceptive. I don't know. I think the test just showed I didn't want to get a
clearance.

~~~
BorisMelnik
Many times they will make comments to get a reaction from you, such as:

"Looks like you are telling the truth.." (even if it shows otherwise)

If you look relieved or surprised, this might be something that they can use
at a later date or further along in the interview. Polygraphs are 100%
interpretation, they are not binary by any means.

~~~
pakled_engineer
Exactly, it's just an interrogation prop like when the East German police
would have the fake telephone where they pretended to make calls to
family/friends and verify your story, and had a button under their desk to
make the phone ring so they could pretend to get just in time information to
refute your story. Modern police will go into an interrogation with a decoy
file folder full of random papers and then go through it claiming the contents
refute your entire story and you'd better confess too.

A standard polygraph trick is to switch it off, and then have a casual
interview during the middle of the test. Then they claim they never switched
it off and you've been lying the whole time as your casual results differ on
the magic box. Props tend to work to get people to trip up on their replies
even if the prop is just a box that randomly scribbles on paper with
absolutely zero scientific credibility.

------
justincormack
The US is pretty much the only country that uses polygraphs with any
frequency. In Europe [1] they are not used. The US needs to stop using the
bogus devices.

[1]
[http://en.wikipedia.org/wiki/Polygraph#Europe](http://en.wikipedia.org/wiki/Polygraph#Europe)

~~~
tptacek
They're mostly discredited here as well. Criminal defendants can't be forced
to take them. In virtually all states, defendants can suppress polygraph
evidence. In some of the states where polygraph evidence is allowed (by
consent of defendants), the defendants apparently also get a civil cause of
action against the polygraph vendor.

Unfortunately, we still use them as part of a hazing ritual to get clearance
for national defense projects. But the poster upthread is probably right that
those kinds of projects aren't the ones you want to be working on anyways.

~~~
learc83
The interesting thing about polygraphs is that they can be an effective
interrogation tool as long as the subject believes they work. (but then again
so Santa Claus if the subject believes in him)

For instance the interrogator says, "the polygraph says you're hiding
something from me, are you sure there isn't something you want to get off your
chest."

The should however, be banned completely because the false positives are so
high that we are crippling many of the agencies that rely on them. We're
forcing them to drastically reduce their potential talent pool based on pseudo
science.

~~~
rdtsc
> the false positives are so high that we are crippling many of the agencies
> that rely on them.

Even worse than that, it selects for people who lie with impunity without any
visible or emotionals qualms about it -- basically it selects for psychopaths.

~~~
sukilot
It _doesn 't_ do that, because it doesn't work at all. Regular interrogation
does that

~~~
learc83
It does have an effect on subjects who believe it works, it's causes them to
believe that the interview knows they are lying. I would expect this to select
for good liars among people who believe the lie detector works.

------
DougWilliams
It may be informative and entertaining to look at some of these videos on my
website:

[http://www.polygraph.com/media](http://www.polygraph.com/media)

And, if you are interested in more, read these essays:

[http://www.polygraph.com/index.php?i-don-t-teach-
countermeas...](http://www.polygraph.com/index.php?i-don-t-teach-
countermeasures)

[http://www.polygraph.com/index.php?the-lie-detector-is-
bulls...](http://www.polygraph.com/index.php?the-lie-detector-is-bullshit-and-
i-have-proved-it)

And yes, I am the Doug Williams who is the subject of this article...

------
USNetizen
These are often used as part of required policy for the US federal government
in certain types of security clearances. They seem to be used more as a
psychological influence on the person undergoing the clearance than actually
working to detect their deception, so I agree with that point in the article.

Case in point, Snowden would have most likely had to undergo at least one of
these polygraph tests for the cleared work he did and that didn't exactly
prevent anything. Plus, people that are pathological liars can essentially
convince themselves that something is the truth which these tests would
rarely, if ever, pick up on as deception.

~~~
a8da6b0c91d
I think the tests do in fact "work" in two senses. First, tons of people with
"compromised" histories unsuitable for cleared work freak out and fail or even
outright confess things they were concealing. That there's no real lie
detection going on is irrelevant. As an interrogation tactic it still
functions to some extent.

Secondly, _a lot_ of nervous nellies fail, even though they're squeaky clean.
For a lot of the work where the tests are used you really do want to exclude
people who can't keep their cool under a bit of pressure. If you freak out
under the kind of questioning done, you're probably going to freak out in a
way that reveals information if somebody starts asking about your work.

~~~
fnordfnordfnord
I disagree, and I think that polygraph tests filter out good people in favor
of deceptive people and convincing liars.

>For a lot of the work

For a tiny fraction of the work. Maybe you underestimate the number of jobs
that use this quackery.

~~~
aschampion
The polygraph acts like the pot use question for many US law enforcement
positions. People rightly recognize that it's absurd, but for the wrong
reasons. It's not there to select for straight edge people who have never
smoked up, but to select for people willing to bend the truth for the sake of
making procedures have the expected outcomes. Law enforcement doesn't want the
guy who feels compelled to cost himself a job by being honest about a roach
when he was 14, not because he did something illegal, but because when asked
on the stand whether he's confident evidence bag #14 never left his sight he's
likely to let the truth get in the way of the legal machine.

The polygraph foremost is a way to arbitrarily filter people for reasons that
interviewer would rather not reveal, and secondly to select for people willing
to put up with the theatrics of procedures while being indifferent to their
supposed purpose.

~~~
sukilot
That's a fine theory but it isn't the reality at all. The people using
polygraphs don't have that level of conspiracy cleverness.

~~~
aschampion
Systemic bias doesn't require that everyone in the system (or even anyone in
the system) be cognizant of the bias, only that the bias selects for qualities
that will reinforce the same systemic processes. People that consent to
polygraphs despite their obvious flaws and interact well with people willing
to conduct them despite those same flaws are more likely to continue or
encourage the use of polygraphs than others. It doesn't require conspiracy. At
the same time, the continued use of polygraphs for so long given how public
and documented their flaws are allows us to ask what actual selective function
they are serving in the system. Besides institutional inertia, the only two
compelling explanations are as a proxy for biases of the polygraph operators
(which must play a part given that polygraphs are not deterministic, robust
detection mechanisms) and as a selective pressure for people who don't have
qualms with these types of systemic dysfunction.

------
loteck
Never been polygraphed but I always wondered about an alternative to the
"emotional control" approach to beating it that is discussed in the article.

My alternative would be to trick my mind into not lying despite the question
asked. So if I was asked "do you live in Chicago?" (i don't) and I wanted to
answer yes, I would simply internally ask myself "is your name loteck?" and
then respond "yes."

I would ignore the actual question asked by the interviewer except to the
extent I need to pick which internal question I would ask myself, of which I
would only have 2. One for yes responses and one for no.

Anybody have any idea if this would work?

~~~
superuser2
Lying on control questions is not advisable. A polygraph would be conducted
inside of a larger investigation which would, among other things, fact-check
your claims by other means. These data would be considered in the
interpretation of your polygraph results. Whether or not you live in Chicago
is very easy to check; when they see that you are lying on control questions
they will consider everything else suspect.

In the contexts in which polygraphs are applied (i.e. security clearance,
witch hunts within security services), simply being suspicious in this way is
enough to cause the negative outcome (i.e. not getting the clearance, getting
fired), so even if it might muddy the evaluation of your response to, i.e.
"Are you a Russian spy?" it would still cause the negative outcome.

It has no bearing on criminal prosecution, because polygraphs are already
inadmissible.

~~~
dean
If you lie on a question that is easily fact-checked, and the polygraph shows
that you told the truth, doesn't that just prove that the polygraph doesn't
work?

To my mind that is a simple test that disproves the effectiveness of the tool.
It should cause a reasonable person to conclude that the tool doesn't work and
should not be used.

~~~
superuser2
>It should cause a reasonable person to conclude that the tool doesn't work
and should not be used.

But it is likely to cause an FBI-drone to conclude that you are attempting to
beat the polygraph and therefore untrustworthy.

~~~
dean
Yes, what a strange situation. I lie to prove that the machine can't tell that
I'm lying and am branded a liar for revealing the truth.

Maybe the machine isn't meant to do anything, and it's the examiner judging
whether you are lying based on how your react to its presence.

------
mml
When I was a kid, the polygrapher for the local maximum security prison was a
member of the family church. He came in to school one day and did a demo for
the kids. One memorable thing he said was that during an examination, there is
only one lie detector in the room, and it isn't the machine.

~~~
sukilot
And there is at least one liar in the room, but it isn't always the
interrogatee.

------
tptacek
I've never taken one. Question: if you're fundamentally convinced that
polygraphs are hokum (as I am), do you actually need any tactics to "beat"
them? Or can you just ignore them and handle the interview the same as you'd
handle any other interview, and just sort of smile and shrug when the
"operator" tells you the machine spat out some significant result? ("Huh,
maybe I just had to burp.")

~~~
fnordfnordfnord
>do you actually need any tactics to "beat" them?

Maybe. Tactics aimed at fooling the machine are really only to bolster the
confidence of the person being tested. It's not the case that you're playing
against a machine though, the machine doesn't "do" anything; it's a game that
you're playing against the examiner.

~~~
tptacek
Right. But polygraphs really are hokum. If you don't doubt that fact, what
advantage does the examiner have? Is it that I'd have to account for the fact
that they might irrationally believe in the machine, and adjust my performance
to fit that irrational belief?

I think what I'm getting at is that the notion of "cheating" or "beating" a
polygraph seems like it dignifies the procedure. It's a little like "beating"
a psychic medium, isn't it?

~~~
fnordfnordfnord
What makes you think that the polygraph examiners "believe" in the machine.
I'm pretty sure most of them don't. I wouldn't always assume good faith on the
part of the examiner, either. In the common use case of culling the herd of
police job applicants, polygraph examiners are there to provide a way to
arbitrarily reject certain applicants. So, in that case, the applicant
basically has to make the examiner "like" him.

It's better than "beating" a psychic medium because there is often a real,
valuable prize to be gained (ie: a job).

As far as I am concerned, even submitting to examination dignifies the
procedure too much.

~~~
tptacek
If the polygraph examiner doesn't believe in the machine and the candidate
doesn't believe in the machine, I'm a little lost as to how the examiner has
any advantage, or why you would need any special techniques to "beat" the
process.

To be clear: I don't think you _do_ need those tactics, but I'm asking, not
asserting; I've never taken a polygraph.

~~~
rdtsc
The advantage is in them hoping you don't know that machine doesn't work.

In fact they try to check for it. Like they might say things like "it looks
like you pizza-ed on this one when you should-a frenchfried, ... hmm that's
interesting'. Where say "pizza" and "frenchfry" are polygraph specific
terminilogy. If you don't ask "hey what does that mean?" they might assume
your read up on and research about how to beat polygraphs.

And on your point of "what if I really don't believe in polygraphs". The
problem is the polygraph measures involuntary emotional response. You might
rationally not believe in efficacy of polygraphs. But emotionally you'd start
breathing faster anyway. Maybe because you are afried the polygraph examiner
will figure out that you really know how polygraphs work.

~~~
tptacek
So if that's the only advantage, I can ignore all sphincter-related advice,
and the polygraph itself as well. I'm happy about that outcome, by the way!

------
faster
When I was in high school I applied for a job in a VW performance shop a
couple miles from my school. They sent me to the owner's neighbor for a
polygraph, which surprised me but didn't seem like a big deal at the time. The
guy was playing 'bad cop' from the second he answered the door, and said he
was disappointed that I hadn't smoked pot on my way over because that makes
reactions more visible on the polygraph.

We went through his questions 3 times. The first time I just answered his
questions, no games. The second time I tried to change my anxiety level sort
of randomly (I had some experience with pretty high-end biofeedback equipment
and knew how to affect the readings somewhat). The third time I used a
breathing exercise that I was taught by a zen master to minimize my anxiety as
much as possible.

The polygraph operator was pissed, I decided that I had no desire to work for
people who thought that was a good use of 45 minutes, and I didn't get the
job.

Everybody won, I guess.

------
jpmattia
I would love to see polygraphs calibrated with a simple game of hi-lo. Pretty
simple metric: Pick a number 1-1024, the questioner gets it right or wrong.

------
S_A_P
To get security clearance you need to go through government sponsored
auditing. They don't want any thetans to get access to state secrets.

------
fnordfnordfnord
The polygraph is quackery. They may as well just phone Miss Cleo and ask her
if someone is lying. But good on them for pointing out how they are still used
to coerce people.

------
rquantz
Given that the test is essentially measuring whether you respond to a question
with an adrenaline burst, I wonder if taking beta blockers prior to testing
can influence the results. That would be my first instinct.

~~~
troisx
Some places test for drugs in your system along with the polygraph test since
beta blockers are sometimes used to help beat the test.

------
zkhalique
Well, this is the first thing I would think of, if I wanted to cheat on a
polygraph test.

Obviously I would just try to be more nervous at the control questions, to
establish a baseline that wouldn't make the lies stand out. I'd imagine I'm
lying on the control questions.

------
jonathankoren
I always thought George Castanza had the best polygraph beating strategy.
"It's not a lie, if you believe it."

~~~
mhartl
"Jerry, just remember: it's not a lie, if you believe it."

[https://www.youtube.com/watch?v=vn_PSJsl0LQ](https://www.youtube.com/watch?v=vn_PSJsl0LQ)

------
mml
The ol' tack in the shoe trick was specifically noted as bunk by the examiner
I knew, and the sphincter clench is semi-widely known.

What I would find difficult with each of these tricks, is that you have to
execute them during control questions, and not during "real" questions.

Keeping track of when to clench or not while simultaneously trying to keep
reality, and one's deceptions straight seems like it would be extremely hard
to do under even mild pressure.

~~~
sukilot
Not to be too much of a truther, but a polygraph examiner has no interest in
admitting that their work is bunk.

~~~
mml
Perhaps he was a bit honest. These things happen sometimes.

------
doorhammer
If I recall correctly this book has an interesting section on polygraphs and a
lot of other inaccurate methods and folklore around detecting lies and deceit:

[http://www.amazon.com/Detecting-Lies-Deceit-Pitfalls-
Opportu...](http://www.amazon.com/Detecting-Lies-Deceit-Pitfalls-
Opportunities/dp/0470516259)

It was really interesting when I read it, though it's a bit old now, so I'm
not sure how much of the material needs to be updated.

------
logfromblammo
The only way to win is not to play. If you are ever in a position where you
have to take a polygraph test, you have already failed.

~~~
PhantomGremlin
_The only way to win is not to play_

This is often forgotten. In so many situations in life, people think they must
make a choice being forced on them, "yes or no" or something similar.

Quite often the best choice is not to not allow yourself to play that game.
Instead, learn to "think outside the box".

------
late2part
This is a great article! There's a reason that polygraph tests are not
normally allowable as evidence in court!

------
Liquix
It does seem much more similar to psychological torture than actual conclusive
detective work...

~~~
mellavora
you say that like there's a difference :)

------
caycep
this is another version of the "machine learning" prob isn't it? the machine
collects a bunch of basic physiological variables and makes a prediction, you
just have to figure out what those variables are, whether it's hr, bp, etc

------
jakeogh
Excellent resource on the pseudoscience of polygraphs:
[https://antipolygraph.org/](https://antipolygraph.org/)

------
snarfy
One of my high school students who was an ex detective taught my class how to
beat them.

He said put a thumb tack in your shoe, and when asked each question, step on
the tack slightly, enough to cause pain. A lie registers as a blip, but so
does pain. If every question has a blip, they cannot differentiate.

~~~
blumkvist
> One of my high school students who was an ex detective

I read this many times. Can you expand on how a detective ended up as a
highschool student? Sounds like a fun story.

~~~
snarfy
> One of my high school students who was an ex detective

Should be

"One of my high school teachers..."

------
beedogs
Polygraphs are about as useful and effective a tool as water-dowsing rods.

------
myhf
There's an incorrectly joined infinitive in the second sentence.

