# Infallible lie detector **URL:** \ **Category:** Great Debates\ **Created:** [June 10, 2008, 5:35pm UTC](https://boards.straightdope.com/t/infallible-lie-detector/452469 "2008-06-10T17:35:11Z")\ **Posts on this page:** 8\ **Page:** 2
**Author:** ![BrainGlutton](https://avatars.discourse-cdn.com/v4/letter/b/82dd89/32.png) [@BrainGlutton](https://boards.straightdope.com/u/BrainGlutton)\ **Post date:** [June 11, 2008, 5:50am UTC](https://boards.straightdope.com/t/infallible-lie-detector/452469/21 "2008-06-11T05:50:12Z")
[QUOTE=gazpacho] Then the use of a lie detector does not find much in the way of useful information. [/QUOTE] **Yes, it does.** If you know I **think** I’m lying, that **is** extremely useful information, regardless of whether what I think is true is objectively true or false. And only someone utterly naive, ignorant or self-deluded about human social relations would think otherwise. We’re talking here about “truth” in the social, not in the scientific, sense. ---
**Author:** ![BrainGlutton](https://avatars.discourse-cdn.com/v4/letter/b/82dd89/32.png) [@BrainGlutton](https://boards.straightdope.com/u/BrainGlutton)\ **Post date:** [June 11, 2008, 5:51am UTC](https://boards.straightdope.com/t/infallible-lie-detector/452469/22 "2008-06-11T05:51:52Z")
[QUOTE=Polerius] It would be a bad thing if we could never tell a lie, especially “white lies”. Examples 1. You are throwing a surprise birthday party for someone, and they ask you “what are you doing at 3pm?” You could tell a white lie that you will be studying, while actually you will be preparing the surprise party for them. 2. Your friend/colleague just got a haircut that you don’t like too much, and he/she asks you if you like it. It would not help anyone if you couldn’t tell a white lie and say that it looks good. 3. In general any case where a white lie is best for the recipient of the lie. [/quote] Trivial. [QUOTE=Polerius] 4) On a more serious note, the classic “Jews in your basement, Nazis looking for them” example. [/QUOTE] Significant. ---
**Author:** ![Polerius](https://avatars.discourse-cdn.com/v4/letter/p/d78d45/32.png) [@Polerius](https://boards.straightdope.com/u/Polerius)\ **Post date:** [June 11, 2008, 6:02am UTC](https://boards.straightdope.com/t/infallible-lie-detector/452469/23 "2008-06-11T06:02:35Z")
[QUOTE=BrainGlutton] Trivial. [/QUOTE] Maybe trivial, but white lies in these situations are the grease that enables the machinery of social interaction to work smoothly. ---
**Author:** ![BrainGlutton](https://avatars.discourse-cdn.com/v4/letter/b/82dd89/32.png) [@BrainGlutton](https://boards.straightdope.com/u/BrainGlutton)\ **Post date:** [June 11, 2008, 6:06am UTC](https://boards.straightdope.com/t/infallible-lie-detector/452469/24 "2008-06-11T06:06:20Z")
[QUOTE=Polerius] Maybe trivial, but white lies in these situations are the grease that enables the machinery of social interaction to work smoothly. [/QUOTE] The “white lies” you refer to are part of **courtesy.** Any functional society wil have room for such, as part of the lubricant that allows humans-as-moving-parts to come into contact smoothly. The machine posited in the OP is designed to correct deceptions far less socially or spiritually useful, and far more seriously destructive. We’re not comparing apples and oranges, we’re comparing apples and money. ---
**Author:** ![Der\_Trihs](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/der_trihs/32/233_2.png) [@Der\_Trihs](https://boards.straightdope.com/u/Der_Trihs)\ **Post date:** [June 11, 2008, 10:26am UTC](https://boards.straightdope.com/t/infallible-lie-detector/452469/25 "2008-06-11T10:26:48Z")
[QUOTE=begbert2] “It’s not against the law to be gay in this country. What’s your problem with it? Are you some sort of bigot?” [/quote] “I am a warrior of God, sinner !” [QUOTE=begbert2] “Why do you care what I believe? What are you aiming to accoplish with prying into my private, personal beliefs about religion?” [/quote] “I intend to save you from the fires of **HELL**! !” [QUOTE=BrainGlutton] This is discussed in the Spider Robinson short story, “Satan’s Children,” featuring not a machine but a drug called TWT – “The Whole Truth” – which, in addition to a mild hallucinogenic/euphoric effect, fills the user with a compulsion to tell the truth – as in, seek out the nearest person you’ve been lying to and set things straight. In the story, this is a high in it’s own right. “It’s not the drug, it’s the truth that’s addictive!” Users soon discard the drug and simply become more honest. [/QUOTE] I recall that story; I the one that came to my mind was _Omnilingual_, in which a Trojan in a extremely popular program of that name used subliminal techniques to induce truthfulness in people, no doubt put there by some well intentioned type. The result : The collapse of civilization, or at least of any parts of civilization that had computers. Few and fewer people cooperated, because they couldn’t stand each other without lies; the birth rate crashed both because men and women couldn’t stand each other without lies, and people couldn’t delude themselves about how expensive and tedious raising children was. While a simple lie detector wouldn’t go that far, I do think it would be bad if it became ubiquitous. I also recall a novel called _Barking Dogs_, a sort of Dirty Harry-esque take on this with a rogue cop that goes after the bad guys who can’t be touched legally because society is so corrupt. The twist is that he has a “Barking Dog”, a wearable perfect lie detector, so that he can know for a fact if the people he goes after are guilty or not even without a trial. I found it interesting that when he suspected that his wife was having an affair, he turned the thing off, deciding that there were truths he didn’t want to know. ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [June 11, 2008, 10:58am UTC](https://boards.straightdope.com/t/infallible-lie-detector/452469/26 "2008-06-11T10:58:50Z")
[QUOTE=Der Trihs] If used sparingly it would probably be a good thing. Used too much, and it would be a disaster. “Little white lies” appear to be a necessary lubricant in human affairs. [/QUOTE] That’s the key failing of the idea, I think - and indeed many hypothetical scenarios such as this - the notion that if something is thus in some cases, it must be thus in _all cases_, or else it is not so in the first. Not everything can be shoehorned into a single category in all possible cases and variants - so I agree, it would work in some cases, but not by any means all. ---
**Author:** ![begbert2](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/begbert2/32/3357_2.png) [@begbert2](https://boards.straightdope.com/u/begbert2)\ **Post date:** [June 13, 2008, 12:23am UTC](https://boards.straightdope.com/t/infallible-lie-detector/452469/27 "2008-06-13T00:23:21Z")
[QUOTE=Polerius] It would be a bad thing if we could never tell a lie, especially “white lies”. Examples 1. You are throwing a surprise birthday party for someone, and they ask you “what are you doing at 3pm?” You could tell a white lie that you will be studying, while actually you will be preparing the surprise party for them. 2. Your friend/colleague just got a haircut that you don’t like too much, and he/she asks you if you like it. It would not help anyone if you couldn’t tell a white lie and say that it looks good. 3. In general any case where a white lie is best for the recipient of the lie. 4. On a more serious note, the classic “Jews in your basement, Nazis looking for them” example. [/QUOTE] To 1 I would answer “It’s a secret; I don’t want to tell you.” I’m not sure if that would tag me as being evasive or not; it really wouldn’t matter, since I’m being open that I don’t feel inclined to reveal my secrets. Remember, this isn’t a truth serum that compells you to talk; it’s a device that reveals if what you _do_ happen to say is a lie or an evasion. To 2 I would answer, “Nah.” If pressed I could go into more detail, depending on the offense of the hair: “I’m old-fashioned.” “I generally prefer long hair on women.” “I’m no fan of hair dye, you know that.” If the person’s life is crushed by this revelation about my lack of excitement about their hair, then they probably already have learned not to be interested in my opinion long ago. To 3…well, that’s rather inspecific. But as it happens, in my daily life I don’t white lie. (I _do_ lie, but only to deliberately decieve and manipulate.) It’s surprisingly easy not to waste your dishonesty on trivial matters. Occasionally some people have mild troubles with it (I have a co-worker who is not keen on getting unpeppy answers to “so how’re you doing?”), but for the most part it’s no biggie. And my opinion on clothes is worth something! (Or would be, if I had a lick of fashion sense.) 4 reminds me of **Der Trihs** ’s “interrogated by a frothing Christian” example - which raises the interesting point - this device would be a serious problem in a society run by or substantially populated by evil people. If people were hunting for you, or a specific class of people that included you, and if being found by these people would lead to suffering or misery, then you’d be screwed. Your only hope would be to get out of dodge, and fast. Fortunately for me, I don’t think the frothing extremist religionists have enough of a grip on the area where I live for this to be a problem for me. Nor do the Nazis, for that matter. So I think I’d be okay. ---
**Author:** ![Aquila\_Be](https://avatars.discourse-cdn.com/v4/letter/a/a698b9/32.png) [@Aquila\_Be](https://boards.straightdope.com/u/Aquila_Be)\ **Post date:** [June 13, 2008, 10:04am UTC](https://boards.straightdope.com/t/infallible-lie-detector/452469/28 "2008-06-13T10:04:58Z")
[QUOTE=Projammer] In the book [The Truth Machine](http://www.amazon.com/Truth-Machine-James-Halperin/dp/0345412885) an infallible lie detector has been invented. Basic summary, no spoilers. It starts out as a large non-portable device, hook a person up to it and ask questions. Green is truth, red indicates an attempt to decieve. Answering a question in a way that is technically or literally true to misdirect the questioner will still trigger a false response. The fifth amendment has been rescinded so you can be put on the witness stand and asked, “Did you participate in robbing xyzzy bank.” Honestly answering that you didn’t lets you walk out the door in five minutes. Refusal to answer is tantamount to a confession. Somewhere about here a policy is put in place where once a year you have to answer, “Have you commited a felony since 20xx (date of implementation of truth machine)?” to be allowed access to government programs and jobs. I believe that at this time all medicine is socialized and covered as a government service. Eventually technology allows it to be put in a briefcase available for purchase and use by the general public. There is a noticable spike in divorces at this point. Ultimately the whole thing is microminiaturized to the point of being a wearable accessory and finally a surgical implant with the indicator on the back of your hand. The question, would the world be a utopia if no one could successfully tell a lie? Or where and how would it fall apart? [/QUOTE] It looks like the infallible lie detector might be almost upon us now. It involves questioning a subject while he’s under a magnetic resonance imaging (MRI) machine and checking the on screen reactions of the suspected perp’s or traitor’s brain activity and identifying the responses that involve deceit. From the link: [Neuroscientist Uses Brain Scan to See Lies Form](http://www.npr.org/templates/story/story.php?storyId=15744871) From the article: > [@](#): > > It is by studying the fMRI pictures that Langleben has come to the conclusion that lying increases blood flow in key areas of the brain. As he sees it, lies aren’t created out of thin air. Instead, he believes your brain has to think of the truth and then make a decision, in a sense, to do the opposite. If you are instructed to say “the sky is green,” Langleben believes your brain first thinks about the sky’s true color, blue, before going with the falsehood. That process shows up on the fMRI scan. And even more exciting: > [@](#): > > It should come as no surprise that with all this talk of looking into the brain to see lies, government agencies are interested in this fMRI technology as well. Imagine if the FBI or the CIA had a test that could say definitively if someone were lying. Imagine not just how that could help uncover spies – the polygraph is still in use to do that — but also how it could be used with terrorists and common criminals. Why would you need coercive interrogation techniques if you could watch a lie forming in the brain? It looks like the system just needs a little tweaking to be made more sensitive, compact and portable and bingo. The truth shall make us free! [Previous page](https://boards.straightdope.com/t/infallible-lie-detector/452469.md?page=1)