# Why is lie detector technology not considered viable in a USA court of law? **URL:** \ **Category:** Factual Questions\ **Created:** [July 29, 2022, 8:11am UTC](https://boards.straightdope.com/t/why-is-lie-detector-technology-not-considered-viable-in-a-usa-court-of-law/968764 "2022-07-29T08:11:34Z")\ **Posts on this page:** 20\ **Page:** 6
**Author:** ![SmartBulbInc](https://avatars.discourse-cdn.com/v4/letter/s/7cd45c/32.png) [@SmartBulbInc](https://boards.straightdope.com/u/SmartBulbInc)\ **Post date:** [August 2, 2022, 10:58pm UTC](https://boards.straightdope.com/t/why-is-lie-detector-technology-not-considered-viable-in-a-usa-court-of-law/968764/101 "2022-08-02T22:58:00Z")
> [@Great\_Antibob](#): > > but the interviewer seemed a lot more concerned about potential foreign ties and kept coming back to that (I have no close family overseas and had only personally been to my parents’ homeland 2 or 3 times at that point and never for more than 2 weeks). What the heck kind of a job were you applying for that required you to disclose if you had “foreign ties?” The CIA? ---
**Author:** ![Yllaria](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/yllaria/32/3452_2.png) [@Yllaria](https://boards.straightdope.com/u/Yllaria)\ **Post date:** [August 2, 2022, 11:41pm UTC](https://boards.straightdope.com/t/why-is-lie-detector-technology-not-considered-viable-in-a-usa-court-of-law/968764/102 "2022-08-02T23:41:02Z")
I was supposed to have a polygraph test as intake for a temporary Christmas job, back in 1974. The operator went over the questions ahead of time and the first few seemed to be about petty office theft. He got to a question about seeing a doctor and found out that I was pregnant. He called off the test. Said that being pregnant would throw off the results. Did not say why. ---
**Author:** ![TriPolar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tripolar/32/3008_2.png) [@TriPolar](https://boards.straightdope.com/u/TriPolar)\ **Post date:** [August 2, 2022, 11:46pm UTC](https://boards.straightdope.com/t/why-is-lie-detector-technology-not-considered-viable-in-a-usa-court-of-law/968764/103 "2022-08-02T23:46:58Z")
> [@SmartBulbInc](#): > > What the heck kind of a job were you applying for that required you to disclose if you had “foreign ties?” The CIA? Or the State Department and plenty of other government agencies and individual security clearances for contractors. Not that they go with the lie detector every time. ---
**Author:** ![Great\_Antibob](https://avatars.discourse-cdn.com/v4/letter/g/e47c2d/32.png) [@Great\_Antibob](https://boards.straightdope.com/u/Great_Antibob)\ **Post date:** [August 2, 2022, 11:51pm UTC](https://boards.straightdope.com/t/why-is-lie-detector-technology-not-considered-viable-in-a-usa-court-of-law/968764/104 "2022-08-02T23:51:42Z")
I’m sure No Such Agency exists. I did end up getting an offer but declined in favor of a career in oil and gas. This was not only more lucrative but also somehow less ethically troubling, especially in the long run. ---
**Author:** ![DrDeth](https://avatars.discourse-cdn.com/v4/letter/d/b487fb/32.png) [@DrDeth](https://boards.straightdope.com/u/DrDeth)\ **Post date:** [August 3, 2022, 3:04am UTC](https://boards.straightdope.com/t/why-is-lie-detector-technology-not-considered-viable-in-a-usa-court-of-law/968764/105 "2022-08-03T03:04:02Z")
Yeah, and the stress of knowing that the wrong answer will cost you your career, and maybe your freedom. And maybe they might ask about your proclivities for sheep sex or a whole host of not that illegal but super embarrassing things if they get out. ---
**Author:** ![WhyKickAMooCow](https://avatars.discourse-cdn.com/v4/letter/w/9fc29f/32.png) [@WhyKickAMooCow](https://boards.straightdope.com/u/WhyKickAMooCow)\ **Post date:** [August 3, 2022, 9:55am UTC](https://boards.straightdope.com/t/why-is-lie-detector-technology-not-considered-viable-in-a-usa-court-of-law/968764/106 "2022-08-03T09:55:28Z")
This video [The Case of Chris Watts - Part 2 - The Polygraph - YouTube](https://www.youtube.com/watch?v=nVZhV7M3mNE) has a useful insight into the use of lie detectors. The polygraph test is done on a suspect (Chris Watts suspected of murder) and immediately afterwards the interrogating officer says “You obviously are a really bad liar” (see 20:15 in the video) when pretending to analyze the results. So the suspect is put on the back foot because he believes the lie detector is a genuinely functional device and that it has caught him out ie. technology succeeds where the previous interviewers have not. So the strength of the device is the mystique and suggestibility that it works, the fact that it can not actually detect lies does not even come into it. One comment on the video puts it best: “The polygraph is useless as evidence, but is ultimately an incredible interrogation tool. She made great use of her time, and wreaked havoc on his psyche.” ---
**Author:** ![Digital\_is\_the\_new\_Analog](https://avatars.discourse-cdn.com/v4/letter/d/a88e4f/32.png) [@Digital\_is\_the\_new\_Analog](https://boards.straightdope.com/u/Digital_is_the_new_Analog)\ **Post date:** [August 3, 2022, 1:28pm UTC](https://boards.straightdope.com/t/why-is-lie-detector-technology-not-considered-viable-in-a-usa-court-of-law/968764/107 "2022-08-03T13:28:44Z")
> [@SmartBulbInc](#): > > What the heck kind of a job were you applying for that required you to disclose if you had “foreign ties?” The CIA? A good number of private sector engineering jobs have security clearance requirements, due to government contracts. I know my current company has a division for that. I didn’t have direct visibility to it, but I’d be shocked if the major cell phone manufacturers I used to work for didn’t also have some. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [August 3, 2022, 5:06pm UTC](https://boards.straightdope.com/t/why-is-lie-detector-technology-not-considered-viable-in-a-usa-court-of-law/968764/108 "2022-08-03T17:06:24Z")
> [@Yllaria](#): > > I was supposed to have a polygraph test as intake for a temporary Christmas job, back in 1974. The operator went over the questions ahead of time and the first few seemed to be about petty office theft. He got to a question about seeing a doctor and found out that I was pregnant. He called off the test. Said that being pregnant would throw off the results. Did not say why. Did you get the job? If not, that sounds like the company had a policy against hiring pregnant women, and possibly other protected classes, and was using the polygraph as cover. ---
**Author:** ![doreen](https://avatars.discourse-cdn.com/v4/letter/d/858c86/32.png) [@doreen](https://boards.straightdope.com/u/doreen)\ **Post date:** [August 3, 2022, 5:19pm UTC](https://boards.straightdope.com/t/why-is-lie-detector-technology-not-considered-viable-in-a-usa-court-of-law/968764/109 "2022-08-03T17:19:42Z")
They didn’t need cover in 1974 - the Pregnancy Discrimination Act didn’t become law until 1978 , after a couple of Supreme Court decisions that found that pregnancy discrimination was not a form of sex discrimination ---
**Author:** ![CookingWithGas](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cookingwithgas/32/485_2.png) [@CookingWithGas](https://boards.straightdope.com/u/CookingWithGas)\ **Post date:** [August 3, 2022, 5:54pm UTC](https://boards.straightdope.com/t/why-is-lie-detector-technology-not-considered-viable-in-a-usa-court-of-law/968764/110 "2022-08-03T17:54:20Z")
> [@SmartBulbInc](#): > > What the heck kind of a job were you applying for that required you to disclose if you had “foreign ties?” The CIA? I’ve never heard about a polygraph for a job interview. But this is a very standard line of questioning for any federal background investigation, even when there is no polygraph, even for a fairly low-level clearance. ---
**Author:** ![kenobi\_65](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kenobi_65/32/13178_2.png) [@kenobi\_65](https://boards.straightdope.com/u/kenobi_65)\ **Post date:** [August 3, 2022, 5:59pm UTC](https://boards.straightdope.com/t/why-is-lie-detector-technology-not-considered-viable-in-a-usa-court-of-law/968764/111 "2022-08-03T17:59:32Z")
> [@CookingWithGas](#): > > I’ve never heard about a polygraph for a job interview. In 1983, my then-girlfriend had to take a polygraph test in order to be hired as an assistant manager at a Radio Shack. There was nothing related to security clearances or background checks for such a job; my guess is that Radio Shack insisted on polygraph tests, in an effort to weed out potential employees who might engage in theft. (Not that it would have actually done that, but that may have been the thinking.) ---
**Author:** ![Mighty\_Mouse](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mighty_mouse/32/7776_2.png) [@Mighty\_Mouse](https://boards.straightdope.com/u/Mighty_Mouse)\ **Post date:** [August 3, 2022, 6:25pm UTC](https://boards.straightdope.com/t/why-is-lie-detector-technology-not-considered-viable-in-a-usa-court-of-law/968764/112 "2022-08-03T18:25:58Z")
Yes, I had to take a polygraph to work at a retail management job c1988. He seemed to be having fun with it more than anything else. Asked more questions about my sexual history than anything relating to financial integrity. ---
**Author:** ![kayaker](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kayaker/32/441_2.png) [@kayaker](https://boards.straightdope.com/u/kayaker)\ **Post date:** [August 3, 2022, 6:29pm UTC](https://boards.straightdope.com/t/why-is-lie-detector-technology-not-considered-viable-in-a-usa-court-of-law/968764/113 "2022-08-03T18:29:08Z")
> [@kenobi\_65](#): > > In 1983, my then-girlfriend had to take a polygraph test in order to be hired as an assistant manager at a Radio Shack. Was the polygraph a RadioShack/Tandy kit sold at the store? 😆 ---
**Author:** ![Yllaria](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/yllaria/32/3452_2.png) [@Yllaria](https://boards.straightdope.com/u/Yllaria)\ **Post date:** [August 3, 2022, 6:35pm UTC](https://boards.straightdope.com/t/why-is-lie-detector-technology-not-considered-viable-in-a-usa-court-of-law/968764/114 "2022-08-03T18:35:36Z")
> [@Chronos](#): > > Did you get the job? If not, that sounds like the company had a policy against hiring pregnant women, and possibly other protected classes, and was using the polygraph as cover. There was no problem getting the job. Management treated scheduling the test as a box to be checked when hiring. Once I went to the appointment, the box was ticked. It was only for the Christmas season and required no lifting, so the pregnancy didn’t matter to them. ---
**Author:** ![kenobi\_65](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kenobi_65/32/13178_2.png) [@kenobi\_65](https://boards.straightdope.com/u/kenobi_65)\ **Post date:** [August 3, 2022, 6:52pm UTC](https://boards.straightdope.com/t/why-is-lie-detector-technology-not-considered-viable-in-a-usa-court-of-law/968764/115 "2022-08-03T18:52:46Z")
> [@kayaker](#): > > Was the polygraph a RadioShack/Tandy kit sold at the store? Winner winner! 😃 (No; actually, they worked with an independent polygraph administrator, who was located about a half-hour away. So, not only did my girlfriend have to take a polygraph exam, she also had to drive an hour round-trip to take the thing.) ---
**Author:** ![needscoffee](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/needscoffee/32/1076_2.png) [@needscoffee](https://boards.straightdope.com/u/needscoffee)\ **Post date:** [August 3, 2022, 7:09pm UTC](https://boards.straightdope.com/t/why-is-lie-detector-technology-not-considered-viable-in-a-usa-court-of-law/968764/116 "2022-08-03T19:09:03Z")
> [@Yllaria](#): > > He got to a question about seeing a doctor and found out that I was pregnant. He called off the test. Said that being pregnant would throw off the results. Did not say why. Obviously - how would he know if it was you lying or the baby? 🙂 ---
**Author:** ![Yllaria](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/yllaria/32/3452_2.png) [@Yllaria](https://boards.straightdope.com/u/Yllaria)\ **Post date:** [August 3, 2022, 7:11pm UTC](https://boards.straightdope.com/t/why-is-lie-detector-technology-not-considered-viable-in-a-usa-court-of-law/968764/117 "2022-08-03T19:11:44Z")
Well, you never can trust babies. ---
**Author:** ![Dr\_Paprika](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dr_paprika/32/3042_2.png) [@Dr\_Paprika](https://boards.straightdope.com/u/Dr_Paprika)\ **Post date:** [August 3, 2022, 7:13pm UTC](https://boards.straightdope.com/t/why-is-lie-detector-technology-not-considered-viable-in-a-usa-court-of-law/968764/118 "2022-08-03T19:13:07Z")
Canada is a huge country. People often misrepresent distance or travel times (sometimes by ignoring traffic effects, sometimes unintentionally) to encourage visitors or make things sound more convenient. **We would be better served if everyone giving people directions had to take a lie detector test.** - So, how far is the new house from Big City? - It’s just _half an hour_(1) from Big City(2) and can be done quickly and easily(3). (1) Pretty sure hours are longer on Saturn. (2) Specifically, the outer edge of Big City Metropolitan Area. But c’mon, how long can it take to cross a city? (3) At 5 a.m. It takes longer from 7am to 7pm. This varies from directions being given in Eastern Canada. - How do I get to your place? - Go down the highway, three clicks past the coffee shop. Turn right at the big tree. Drive for twenty minutes and cross the bridge. Then drive for another twenty minutes. It’s the house with a fence. ---
**Author:** ![Saint\_Cad](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/saint_cad/32/18907_2.png) [@Saint\_Cad](https://boards.straightdope.com/u/Saint_Cad)\ **Post date:** [August 3, 2022, 7:33pm UTC](https://boards.straightdope.com/t/why-is-lie-detector-technology-not-considered-viable-in-a-usa-court-of-law/968764/119 "2022-08-03T19:33:55Z")
> [@Dr\_Paprika](#): > > Science may, however, show lies can be detected in other ways with more accuracy (possibly functional MRI or detailed facial muscle analysis - this is not my expertise). I saw one claim that furrowing of the forehead = lie is the most accurate lie detector and that the Secret Service uses that fact in their investigations. ---
**Author:** ![SmartBulbInc](https://avatars.discourse-cdn.com/v4/letter/s/7cd45c/32.png) [@SmartBulbInc](https://boards.straightdope.com/u/SmartBulbInc)\ **Post date:** [August 3, 2022, 7:48pm UTC](https://boards.straightdope.com/t/why-is-lie-detector-technology-not-considered-viable-in-a-usa-court-of-law/968764/120 "2022-08-03T19:48:47Z")
> [@CookingWithGas](#): > > I’ve never heard about a polygraph for a job interview. But this is a very standard line of questioning for any federal background investigation, even when there is no polygraph, even for a fairly low-level clearance. I mean… Sure, you are going to be asked those sorts of questions in any sort of hiring prosses that requires any security clearance. But, being strapped to a lie detector is still little much for the average position. [Previous page](https://boards.straightdope.com/t/why-is-lie-detector-technology-not-considered-viable-in-a-usa-court-of-law/968764.md?page=5) [Next page](https://boards.straightdope.com/t/why-is-lie-detector-technology-not-considered-viable-in-a-usa-court-of-law/968764.md?page=7)