What is truth serum?

Indian officials plan to inject captured Mumbai terrorist with the "truth serum," sodium pentothal, but history tells us that the technique isn't up to the task















Share on Tumblr

During World War II, these drugs were used in a very different way. They were the first intravenous anesthetics and were used to treat traumatized soldiers who had lost their memories or had aphasia [loss of the ability to speak or process language due to brain injury]. Doctors found that using these drugs would make it easier for people to say what happened, and this helped them feel better.

As a result, a lot of doctors who had been in the military during the war were familiar with these drugs. Sodium amytal and pentothal were no longer just used as surgical anesthetics, although that was their most common use, but they were sometimes used for this psychiatric purpose of getting people to talk.  In most cases, the drugs were not used in interrogations, but to help people talk about their memories in psychiatric consultations.  However, some of these military doctors eventually became consultants for police forces or they did psychiatric research for the government and began exploring different ways of using these drugs for interrogation.

Do experts believe they really work?
The idea of a "truth serum" has never been widely accepted. Although there have been waves of enthusiasm for the idea of a drug that can extract information reliably, there has been even more skepticism. Ever since the 1920s, many judges, psychiatrists, and scientists have rejected the idea that there is a drug that can get memories out intact. They have claimed, instead, that it makes people feel like talking, but it also puts them in a state of extreme suggestibility: people will pick up on cues about what questioners want to hear and repeat that back. This is one of the reasons that statements made under the influence of these drugs have never, as far as I know, been accepted in an American court.

After 9/11, there were discussions in the national papers about whether it's a good idea to interrogate suspects using these drugs. Every time there is a desperate need for information from people, you get speculation about whether these drugs are going to get that information. But you also get consistent warnings that the information may be less reliable than what you would get without the drugs. That skepticism was there right from the start 80 years ago.



22 Comments

Add Comment
View
  1. 1. jinchoung 06:14 PM 12/6/08

    why is it STILL so unclear? if it is not a toxic or overtly harmful drug, why don't they just TEST IT? do an experiment with a control and get people to remember an answer to a non yes or no question (that wouldn't be subject to common knowledge - e.g. what color underwear did you wear tuesday?) and instruct them to do their level best NOT to reveal it. give the experiment group (of 100 people say...) the drug and then see if they reveal the info more times than a group given a placebo. SOOOOoooooo easy to test. WTF?

    Reply | Report Abuse | Link to this
  2. 2. piedpiper in reply to Scientz 09:27 PM 12/6/08

    There's a spelling mistake in the last commant.

    Reply | Report Abuse | Link to this
  3. 3. jgrosay 09:17 AM 12/7/08

    A technique used for obtaining unwanted confessions is REM sleep deprivation. After a few days on it, you tell the whole story in exchange of a candy or a nap

    Reply | Report Abuse | Link to this
  4. 4. ZenaV 08:18 PM 12/7/08

    I have a list of people I'd like to see on these drugs...

    Reply | Report Abuse | Link to this
  5. 5. jstepp590 11:50 AM 12/8/08

    There is a new form of lie detector test called a fMRI lie detector that is highly accurate. It is based on watching brain activity in real time. In the brain, a persons imagination and memory are in two different places so if someone is lying it is immediately obvious because of where the activity is taking place. Some reports place the accuracy at over 99%, with the only false reading happening when the data is read incorrectly by the operator. This technology, imho, should be in widespread use by law enforcement around the world and should be mandatory when peoples lives are at stake. It would also do wonders for filtering out prisoners who have been falsely convicted.

    Reply | Report Abuse | Link to this
  6. 6. inboulder 12:29 PM 12/8/08

    This article didn't present any clear opinion or information whatsoever. Where are the studies?

    Reply | Report Abuse | Link to this
  7. 7. redfoxone 01:58 PM 12/8/08

    I dunno but rest assured the US Government uses it.

    hess
    www.online-privacy.se.tc

    Reply | Report Abuse | Link to this
  8. 8. pinginfan in reply to jstepp590 05:10 PM 12/8/08

    Doing that would be a clear violation of the fifth amendment.

    Reply | Report Abuse | Link to this
  9. 9. science+music=cool in reply to jgrosay 02:38 PM 12/9/08

    under geneva convention isnt getting somebody to admit to something well forcing a confession whatever. isnt that a violation of human rights. now agree or disagree but its still in there. so even if you had a magic potion that would make you tell people everything then its still a violation of basic human rights. now im english but its still in the america constitution like that guy/ girl says. fifth amendment. magic potion or not you cant use it by the very definition of unaliable rights. having said that i would so love to do research into this kind of thing, how it works on the brain ectect. isnt that what they were originally tying to do with LSD?

    Reply | Report Abuse | Link to this
  10. 10. science+music=cool 02:41 PM 12/9/08

    yeah id like to see the studies. and the stuff on the new lie detector. how does it work if you actually believe what you are saying. i mean if you are lying on the spot then yes i can see it working but how if its prefabricated?

    Reply | Report Abuse | Link to this
  11. 11. ajhil in reply to jinchoung 03:34 PM 12/10/08

    This is NOT unclear! Work with pychoactive drugs in numerous different contexts have demonstrated beyond any shadow of a doubt that none of them specifically promotes truth-telling. Most of these drugs are depressants, which can reduce inhibitions by depressing those brain functions first. In doing so they make (some) people (some of the time) more talkative than they ordinarily might be; however, these people are just as likely - in fact, sometimes more likely - to invent the things they say as to tell the truth.
    Case in point: do you consider the things that people say when they're drunk to be especilly truthful or reliable? Alcohol is no different in principle than scopalamine or barbiturates or benzodiazepines or anti-psychotic drugs like Thorazine. None of them is a genuine "truth serum."
    This is an urban myth that is long overdue for the scrap heap!

    Reply | Report Abuse | Link to this
  12. 12. ajhil in reply to jinchoung 03:36 PM 12/10/08

    This is NOT unclear! Work with pychoactive drugs in numerous different contexts have demonstrated beyond any shadow of a doubt that none of them specifically promotes truth-telling. Most of these drugs are depressants, which can reduce inhibitions by depressing those brain functions first. In doing so they make (some) people (some of the time) more talkative than they ordinarily might be; however, these people are just as likely - in fact, sometimes more likely - to invent the things they say as to tell the truth.
    Case in point: do you consider the things that people say when they're drunk to be especilly truthful or reliable? Alcohol is no different in principle than scopalamine or barbiturates or benzodiazepines or anti-psychotic drugs like Thorazine. None of them is a genuine "truth serum."
    This is an urban myth that is long overdue for the scrap heap!

    Reply | Report Abuse | Link to this
  13. 13. ajhil 03:36 PM 12/10/08

    This is NOT unclear! Work with pychoactive drugs in numerous different contexts have demonstrated beyond any shadow of a doubt that none of them specifically promotes truth-telling. Most of these drugs are depressants, which can reduce inhibitions by depressing those brain functions first. In doing so they make (some) people (some of the time) more talkative than they ordinarily might be; however, these people are just as likely - in fact, sometimes more likely - to invent the things they say as to tell the truth.
    Case in point: do you consider the things that people say when they're drunk to be especilly truthful or reliable? Alcohol is no different in principle than scopalamine or barbiturates or benzodiazepines or anti-psychotic drugs like Thorazine. None of them is a genuine "truth serum."
    This is an urban myth that is long overdue for the scrap heap!

    Reply | Report Abuse | Link to this
  14. 14. ajhil 03:42 PM 12/10/08

    Sorry about the multiple posts. My mistake!

    Reply | Report Abuse | Link to this
  15. 15. monkeyrave in reply to science+music=cool 03:18 PM 12/11/08

    Yes I believe that they were trying to do this with LCD and with any type of spychoactive or hallucinogen drug; just because you cannot control what you do sno how can you lie or tell the truth.For this reason;under the influence of these drugs you are inclined to talk when asked something but the answer wont always be right.Althought there might be alot of answers that a person might give the truth is bound to be in there obscured by all the other stuff the person might have said.And yes I love studying drugs and the effects they have on the human body.They are so interesting!

    Reply | Report Abuse | Link to this
  16. 16. Chithra KarunaKaran 06:31 PM 12/12/08

    What troubles me is that the police in India, a democracy, is being reported as planning to use a so-called "truth serum" drug sodium pentathol to elicit information from the captured terrorist.

    This is troubling. He certainly should be questioned but any form of coerced confession much less torture, should be completely unacceptable.

    The Indian media is not displaying its investigative responsibility by failing to provide any reports on the condition of this political prisoner.

    Chithra KarunaKaran
    Ethical Democracy As Lived Practice
    http://www.EthicalDemocracy.blogspot.com

    Reply | Report Abuse | Link to this
  17. 17. pratandon 05:28 PM 12/15/08

    Recently there was a case in India where a teeenage girl was murdered and her dentist father was being falsely implicated for this heinous crime. At the same time, three other persons were arrested for the same crime and were placed under this test. Now this test was administrated at different places/ time to these three persons. However all of them came up with a very similar narration of the sequence of events when placed under this so called truth serum test. Is there a likelihood that all three persons can come up with a similar story, just because of 'suggestibility' factor? Please enlighten me on this.

    Reply | Report Abuse | Link to this
  18. 18. verdai in reply to jstepp590 05:26 PM 1/23/09

    say!
    that must be wonderfull, we have waited so long to overcome this problem.
    I sure hope it is true.
    Seeing many articles about brain scanning, etc,...
    such use would be worth all the others,
    in this world-

    Reply | Report Abuse | Link to this
  19. 19. verdai in reply to verdai 05:35 PM 1/23/09

    The MRIs, or what ever, that is; not any drugs which as we all know cannot control the slimey human speech. or is that reflection true?

    Reply | Report Abuse | Link to this
  20. 20. verdai 05:37 PM 1/23/09

    to and re: jstepp

    Reply | Report Abuse | Link to this
  21. 21. verdai 05:42 PM 1/23/09

    to and re: jstepp
    the MRIs, whatever, that is; since we all know that drugs cannot control the slimey human spoken word.
    Any better reflection of truth would be a great advance.

    Reply | Report Abuse | Link to this
  22. 22. dorothymarie18 07:27 PM 7/6/09

    I would really like to know if it really works..and where would I go to get it done?

    Reply | Report Abuse | Link to this
Leave this field empty

Add a Comment

You must sign in or register as a ScientificAmerican.com member to submit a comment.
Click one of the buttons below to register using an existing Social Account.

More from Scientific American

Follow Us:

See what we're tweeting about

Scientific American MIND

Tweets could not be retrieved at this time

Free Newsletters


Get the best from Scientific American in your inbox

Solve Innovation Challenges

Powered By: Innocentive

  SA Digital
  SA Digital

Science Jobs of the Week

Email this Article

What is truth serum?

X
Scientific American MIND iPad

Tap into your MIND

Get Both Print & Tablet Editions for one low price!

Subscribe Now >>

X

Please Log In

Forgot: Password

X

Account Linking

Welcome, . Do you have an existing ScientificAmerican.com account?

Yes, please link my existing account with for quick, secure access.



Forgot Password?

No, I would like to create a new account with my profile information.

Create Account
X

Report Abuse

Are you sure?

X

Institutional Access

It has been identified that the institution you are trying to access this article from has institutional site license access to Scientific American on nature.com. To access this article in its entirety through site license access, click below.

Site license access
X

Error

X

Share this Article

X