Polygraph or Placebo?

[macgyver]

From Bob Parks' latest email:

LIES: REPLACING POLYGRAPHS WITH BRAIN IMAGING IS A BAD IDEA.
WN has long recommended that the polygraph be replaced by a coin
toss. It would catch half of the lies, which is a lot better
than the polygraph. There would be a little "collateral damage"
from false positives, but there's a lot of that anyway. However,
the Wash Post on Tuesday had a story about discrepancies between
polygraph results obtained by different federal agencies. Who
could be surprised? We are forced to admit that the coin toss
would suffer the same difficulty, presumably to the same extent.
According to an editorial in yesterday's Nature, however, there
are two start-up companies preparing to offer fMRI brain scanning
devices as lie detectors. Many neuroscientists think the claims
made for fMRI are overblown. Should company officials therefore
be asked to submit to brain scans? That's the real problem. If
it works, it would represent the ultimate invasion of privacy.

I've often thought that even if the polygraph doesn't work, it may have a useful place when used to interrogate a suspect. The problem is that the suspect has to believe that they work.

If the suspect is of the opinion that they can't lie without being detected, would they not be more likely to tell the truth?

In this way, you might be able to get more truthful answers, but the results of the actual polygraph are meaningless (just as they are now).

 

[This Guy]

From Bob Parks' latest email:



SNIP

If the suspect is of the opinion that they can't lie without being detected, would they not be more likely to tell the truth?

SNIP

There was a stupid crooks story that involved police using a copy machine, with a sheet of paper with the word LIE written on it, to get a crook to confess. They convinced him it was a lie detector. If that story was true (it was reported as truth, but I have no reference) it would tend to confirm your statement

 

[macgyver]

There was a stupid crooks story that involved police using a copy machine, with a sheet of paper with the word LIE written on it, to get a crook to confess. They convinced him it was a lie detector. If that story was true (it was reported as truth, but I have no reference) it would tend to confirm your statement

It looks like the jury is still out on whether that happened or not:

http://www.snopes.com/legal/colander.htm

good story though..

 

[SteveGrenard]

And then there is this if we are talking about alternatives to truth detection:

http://www.brainwavescience.com/

 

[This Guy]

It looks like the jury is still out on whether that happened or not:

http://www.snopes.com/legal/colander.htm

good story though..

How'd you find that so fast? hehe

Good job

Yea, true or false, I like it.

But I think if someone believed the detector truly worked, they would be more likely to tell the truth.

I do have misgivings about any form of lie detector though. If your forced to take the test, seems like a form of self incrimination. I think we're protected from that aren't we? The scary thing is that some companies (I think) and unless changed recently, our Government can force you to take the test, under some conditions. And since the test are not perfect, there is broad room for errors/problems. Kinda scary to me anyway!