How can you tell if someone is lying? • Hacker News Board

Re: How can you tell if someone is lying?

#51

Post by parsimo2010 » Sun, Mar 28, 2021, 4:52 AM UTC

clouddrover wrote: post #28

parsimo2010 wrote: post #17

Most of us can’t reliably tell when a romantic interest is actively signaling their mutual interest. If we can’t get cooperative activities right, most of us don’t have a chance to spot a liar through nonverbal cues. The fact is that random effects are huge when dealing with people. Is that person you’re interrogating not showing emotion because they’re a psychopath, or because they were taught not to display emotion…

> current polygraph techniques can allegedly be beaten with training No training is needed because polygraphs don't work. Polygraph testing is about as worthwhile as astrology: https://www.apa.org/research/action/polygraph https://www.salon.com/2000/03/02/polygraph/ And inadmissible in court in many places: http://www.austlii.edu.au/au/journals/MurUEJL/2000/6.html > if trained polygraph techs with special equipment T…

I’m not going to vigorously defend polygraphs, but I’ll play Devil’s advocate for a bit. From your the Salon piece you linked to, “In studies, polygraph diagnoses are often wrong, with rates hovering around 80 percent correct”

Which to some people sounds terrible. I certainly wouldn’t want to hang a murder conviction on something with a 20 percent error rate. But on the other hand, 80 percent is better than all but one of the cited results from the Atlantic article, and beats the results from all experiments using untrained people. These con artists are, at best, performing on par with specific lie detection training.

Maybe the equipment is just for show, but who’s to say that further biometric measurements, such as functional MRI, wouldn’t significantly increase the accuracy of biometric lie detection (still technically within the realm of nonverbal cues from the Atlantic article)? I don’t think it could be 100% accurate, but I can reasonably see future polygraphs being legitimate tools for lie detection.

I wouldn’t want my murder conviction to hang on the results of a current polygraph, but I would be satisfied using one to catch an office supply thief. Well, except it would probably be cheaper to just let someone keep stealing supplies than to pay $8k per employee to administer the tests.

Re: How can you tell if someone is lying?

#52

Post by [deleted] » Sun, Mar 28, 2021, 4:58 AM UTC

sushisource wrote: post #15

aidenn0 wrote: post #7

Any time I talk to someone about this evidence it's always "yeah, most people suck at telling liars, but I'm good at it." Lake Wobegon effect for people reading.

I think people probably immediately think about how they react to their spouse or other very close relationships, and I suspect (haven't looked it up) that people are actually pretty good at detecting lies in those situations because we have so much experience with how that person acts. Detecting the lies of strangers? Yeah... good luck.

[deleted]

Re: How can you tell if someone is lying?

#53

Post by clouddrover » Sun, Mar 28, 2021, 4:59 AM UTC

parsimo2010 wrote: post #51

clouddrover wrote: post #28

Earlier quoted context omitted.

> current polygraph techniques can allegedly be beaten with training No training is needed because polygraphs don't work. Polygraph testing is about as worthwhile as astrology: https://www.apa.org/research/action/polygraph https://www.salon.com/2000/03/02/polygraph/ And inadmissible in court in many places: http://www.austlii.edu.au/au/journals/MurUEJL/2000/6.html > if trained polygraph techs with special equipment T…

I’m not going to vigorously defend polygraphs, but I’ll play Devil’s advocate for a bit. From your the Salon piece you linked to, “In studies, polygraph diagnoses are often wrong, with rates hovering around 80 percent correct” Which to some people sounds terrible. I certainly wouldn’t want to hang a murder conviction on something with a 20 percent error rate. But on the other hand, 80 percent is better than all but o…

> Maybe the equipment is just for show

Yes, it's a con.

> but who’s to say that further biometric measurements, such as functional MRI, wouldn’t significantly increase the accuracy of biometric lie detection

That isn't what they're doing. The "who" that will say it is actual, statistically significant evidence that it works.

Re: How can you tell if someone is lying?

#54

Post by dllthomas » Sun, Mar 28, 2021, 4:59 AM UTC

jmcgough wrote: post #26

I played a ton of Among Us in 2020, which is a game where you have to figure out which of your friends are lying. I quickly learned that going off "well they're acting pretty guilty" was an easy way to lose. A friend of mine would immediately jump to accuse me whenever I cast suspicion on them, even if they were innocent. Way better to rely on actual evidence and not hunches, even more so when it comes to giving some…

One Night Ultimate Werewolf has the additional wrinkle that initially most (or all) players don't even know whether they should be lying or not.

Re: How can you tell if someone is lying?

#55

Post by parsimo2010 » Sun, Mar 28, 2021, 4:59 AM UTC

roenxi wrote: post #25

The article seems to have avoided mentioning the easy way of detecting a lie - go and collect some evidence then compare it to what the person is saying. Incentives count as weak evidence for detecting lies. While not foolproof, it is much more effective than looking for verbal cues. Detecting lies by assessing someone's demeanour is a symptom. The average person seem to have this unshakeable belief that they are psy…

Because that’s going beyond the idea of nonverbal cues. It’s easier to tell is someone is lying about a murder when you found the murder weapon with their fingerprints on it. If you have evidence you don’t really need to worry about spotting the lies.

Re: How can you tell if someone is lying?

#56

Post by carapace » Sun, Mar 28, 2021, 5:00 AM UTC

alexpc201 wrote: post #33

I recall reading about a patient with split-brain (severed corpus callosum) could tell when people were lying. It seems there are verbal and physical cues when we lie.

> It seems there are verbal and physical cues when we lie.

Yes. Not being able to detect lies is a social construction, part of culture. (And so the results reported in TFA are technically useless because everyone involved is operating as part of the unconscious "conspiracy" and so would naturally "discover" that it's hard to detect lies.)

You can tap into this with hypnosis, but it's unpleasant, like being an alien. Imagine being the only person in the room that can tell when someone, anyone, is lying. It would be pretty creepy, eh? Like Twilight Zone creepy. People would shun you. You'd have to hide the ability, eh? And so we come full circle: we all can tell but we're taught not to as children.

Re: How can you tell if someone is lying?

#57

Post by Godel_unicode » Sun, Mar 28, 2021, 5:01 AM UTC

dwighttk wrote: post #23

aidenn0 wrote: post #7

Any time I talk to someone about this evidence it's always "yeah, most people suck at telling liars, but I'm good at it." Lake Wobegon effect for people reading.

Lake Woebegon effect is such a terrible name. It is very easily possible that every student in a small town is above average compared to e.g. the national average.

I have to question whether you're trying to prove GPs point, as this is hilariously incorrect. Unless you're using very unlikely values for easy and/or small.

Re: How can you tell if someone is lying?

#58

Post by dathinab » Sun, Mar 28, 2021, 5:04 AM UTC

Yup, many of the "signs someone is lying".

Are actually signs someone is uncomfortable/insecure.

And while you might be such because you lie, you might also be such without lying and you might not be such when lying.

Re: How can you tell if someone is lying?

#59

Post by Godel_unicode » Sun, Mar 28, 2021, 5:06 AM UTC

easton wrote: post #19

mettamage wrote: post #4

Two thoughts: 1) If law enforcement ever has the time, they might want to play Maffia or Werewolf. Playing those games enough makes you realize how idiosyncratic lying can be. 2) I'm glad to know that my lecture on lying when I studied psychology basically had the same conclusions as this article.

Among Us is the most recent version of those games, and it made me realize how good my friends were at gaslighting me.

What if I told you that playing a low-stakes game and real life are not the same thing?

Re: How can you tell if someone is lying?

#60

Post by arp242 » Sun, Mar 28, 2021, 5:08 AM UTC

roenxi wrote: post #25

The article seems to have avoided mentioning the easy way of detecting a lie - go and collect some evidence then compare it to what the person is saying. Incentives count as weak evidence for detecting lies. While not foolproof, it is much more effective than looking for verbal cues. Detecting lies by assessing someone's demeanour is a symptom. The average person seem to have this unshakeable belief that they are psy…

Even this is hardly fool-proof, since human memory is far from perfect. Someone might say "I was at Tesco's at 4pm" and later video evidence shows they were actually at Tesco's at 2pm. Did they lie or misremember? Unfortunately, police are often very quick to assume that such a small mistake is done in bad faith and that they're lying. In reality, a lot of people just won't remember the exact time they were at Tesco's weeks or months ago; they may even get the day wrong, or the location.

This is why you just exercise your rights and not talk to the police. Let them figure it out instead of risk being branded a "liar" over a simple mistake.