The thing I love best about lie detectors in their various forms is how the provide a fruitfull example of why "double blind" trials etc have limits.
Which in an example of circular reasoning of the best kind ;) becomes very obvious once you understand what the limits are...
A classic example is the story of a couple of police officers using a "fake" lie detector and got improved conviction rates, and it was the success that gave rise to people finding out what they were upto (nothing like success to make you enamies).
And although apparently an "urban legand" it appears based on a "hushed up" reality to protect the good name of the force involved... (anyone for a"conspiracy theory"?).
Whatever the truth it does bring out the why of the "placebo effect" of lie detectors, in that people belive what they want to belive.
Behind the story are some verifiable facts that appart from the actuall numbers appear to be fairly universal in WASP countries.
The story has a belivable asspect that hangs on the following points,
Police officers after using their considerable "experiance", "local knowledge" and "hinky detectors" usually have a very good idea of who was very probably behind a particular petty crime. It's just a matter of getting a conviction that is the real hard part of the job.
Theres nothing new here it's how something like 99% of petty crime enquiries start, and of the actual successfull conviction (which is very low and often below 5%) 99% of the convictions are due to "criminal stupidity" of which something like 85% are because the criminals talk about what they have done and others "grass them up" no hounour amongst "brotherhood" of theives then. (Coincidently there is growing evidence that women theives are less likley to be caught by "flapping their gums" than men and take simple and sensible precautions which work the system very much to their advantage).
The problem the police have is how to get a "stupid" "perp"/"scrote" to "fess up" in the shortest period of time.
With politicians demanding "lock them up" and "bad lawyers" getting 60% or more "perps to walk" out of court it's not an easy job in "target driven society" with the press claiming politicians are incompetent and cannot stop "little old ladies being betten in their homes" or "children being abused/abducted by sickos" etc.
Under such preasure some countries politicians have changed the age old "right of silence" rules others have allowed pre-trial hearings where a suspects supposed "bad charecter" can be brought up and then addmitted into the trial as evidence, not as would otherwise be "inadmissable hearsay".
Even with this the official "conviction rate" stays stubbonly low.
Police forces try other tricks such as down grading certain crimes, and under "officialy" reporting others then there is the age old "taken into consideration" tricks. So the real low conviction rate can be a lot less than a quater the "official conviction rate".
It is also why the likes of politicians and some ACPO members are "so enamered by DNA Databases".
So with such an example from on high it's not surprising that front line cops are looking for new methods where even a 1% increase in crimes to court would make them look good and get the seniors their target met bonus which is a sure way to get promotion...
But and it's a big but with criminals getting smarter, how do you do it? And in a way that would get past the court system (theres the old "Miranda might be right" but was not a "good girl for the boys").
Oh and of course Human rights, rubber hoses and wet blankets realy are "so old school" (1970's) as is "good cop bad cop" and the perps have started to wise up due to their TV watching.
Anyway with some of the background out of the way back to the story,
Therefore what where these two cops going to do. It had to be a new method and they wanted it to be "high tec" as courts still don't appear to understand low tec, but it had to be cheap and easy.
As always some one arround the water cooler or coffee machine stated the "bleeding obvious" and suggested "we need lie detectors" as these are consistantly seen to convince juries and get perps to fess up and are "advertised a lot" on TV in the slightly brighter perps viewing schedual so they belive it as do politicians and burecrats (we now call this the CSI effect, but it's older than Kojack's lollypop ;)
Then a bright idea occured to the cops, you very rarely get to see a real lie detector in use on TV because it looks like "Victorian health" or "1950's brain" research, and is realy realy slow viewing and no where near as entertaining as watching a full frontal lobotomy (lookup "Ice Pick" method to see why).
Supposadly these cops eventualy realised that it needed to be,
A) simple to use (they are cops after all ;)
B) had to have a nice easy to understand output (we are talking "stupid" "perps" here)
C) had to be high tec looking (remember the TV education)
D) not easily recognised by a perp.
E) easily and quietly available to the cops at no cost or real risk.
The last two points were the Achillies heal to the "water cooler" musings.
Then as the story has it one day the department got some new equipment and over the first coffee of the shift somebody said "hey did you see what got delivered yesterday it looks like the bridge of the USS Enterprise and it's only a photocopier, you recon the admin staff will be able to work it".
After a couple of more cups of coffe a light started dimly in one cops mind, and as he's a cop he just can not let it go.
So over a beer he says to his partner "I've had an idea about our perp problem". After a little discussion and a lot more libationary muscle relaxant (hey being a cop is stressfull the beer helps you calm down ;) they have worked out some basic details and it's such a funny idea they have a good laugh over it for the rest of the night.
A few days later they get called to a crime scene and one look tells them the MO and they know the perp, they've pulled him down town so many times he's getting enough frequent flyer miles to get to Auz. The trouble is he just acts dumb and there is never quite enough evidence to get past his "well suited n booted" ex "ambulance chaser" "shark", so the "13@5t4rd" (think illegitimate perp) keeps getting away with it.
So there they are the boss is giving them grief and the coffee tastes like the bottom of an ash tray that has not been cleaned in a year (yup they know the taste they remember it well from their "initiation hazzing"). They've only got a little time and they know the perp is going to be "walking" again.
They know that due to "cost effectivness" there will never be any real forensic work carried out it costs to much and there is no likelyhood of a conviction so why waste the money.
Then the idea comes back and the cops think what the heck lets give it a try, the usual is not working.
So one of them goes for a chat with the perp whilst the other gets some photocopy paper and puts TRUE and FALSE on a couple of sheets of it.
They then drag the perp down to the "bridge of the USS Enterprise" stick his hand under the cover and ask him a few questions they know the answers too. With each answer from the perp one cop presses the button there's a beep a whirl and out pops a bit of paper. The cop takes it off and appears to pass it to the one asking the questions in reality he's actually passing the TRUE or FALSE paper over which is then held up for the perp to see.
Very soon the perp is getting those "sure signs" the cops know and love he's taken the bait. Half an hour later the perp has fessed up to not just this crime but a whole load of others.
The cops shove the photo copy paper into the folder and take it and the perp back to the interview room they sit the perp down and start the formal interview which is being recorded. Each time the officer says "You know we know you did X on Yday do you want to tell us about it?" and if the perp starts hesitating the other cop just says "You know we know because we've got the evidence to prove it and who's the jury gon'er belive" and lifts the folder up to the perp.
A little while later the confession is written up and signed and they let the perp go before the Shark can spring him. They then show the conffession and the tape to the boss he's impressed they made it look so easy.
The perp knows that what he's said on tape is true because it is and so down he goes for a short stretch (the cops had a word with the judge especially as the perp dropped others in the net).
After this great success they try it again with those dropped in the net. And again it works like a charm. The Cops are on a roll, their conviction rate starts to rise and promotion is being hinted at.
And then the problem starts. soon these cops don't bother realy thinking about what they are doing, they just pull in "the usuall suspects" and one will "roll over" to the lie detector. Covering it up gets hard and that's when one of their "brother's in arms" colleagues finds out and grasssess them up (there's nothing meaner than "office politics" when promotions in short supply")
What does the boss do when he finds out?
Obviously it's got to stop but the perps have confessed in ways where the confession can be shown to be true, it's brought in other criminals where it's worked. And again it's true as the criminals stories contain details which hit with details in the crime file. So nobody has been hurt (well maybe not) so it's not done any harm the real danger is it's going to be politicaly embarising and those that promote have long memories...
Therefor the story has it he chews the cops out good and propper reads them the riot act and warns them if they ever do it again etc etc...
Things return to normal and the issue appears to have passed but the perps talks the word goes around and eventualy it becomes "street talk" with the likes of "Hey you hear about JoJo them cops got some new lie detector it read his mind his brief say it wern't legal but nuffing he can do cause the it's da truth". The story spreads and get interested
As all good stories go somebody as usuall finds out or suspects from what's said what the truth behind the lie detector is.
And when it getts down on the street that it's just a photo copy machine then the story realy realy get's around with "Hey man that JoJo he sure is a dumb ass he fessed up to a photo copier you'd think he was smarter than that and he went and grassed up "Billy-Bob as well".
The point of the story appart from it has it's funny points, is that when you mix facts in with what people think is true then it becomes true untill something quite major makes them change their mind.
In this it is just like the medical "placebo effect" where if a patient belives they are going to get better they start to show some measurable improvment, however if it's a serious illness then long term result is still the same they sucumbe to the pathogen...
Where ever humans are involved you get the same "short term" "confirmation of theory" simply because they want it to be true. So other factors make it happen. But as with things like CCTV and some drugs trials the long term results are the same or worse than before.
Anyway speaking of the medical fraternaty I've just got out of hospital, yet again I have had a very bad rapid onset (bacterial) infection at an "operation site" but with the bad fever and inability to get rational communication with first responders etc they started checking me out for a sombrero and a small curly tail, thankfull this "gringo pig" did not have the H1N1.
The trouble is though they put you and your stuff in infection control which usually means you get seperated from all your worldly goods (including the shirt off your back). And lets face it electronics and liquid infection control do not mix unless you have an urge to "walk on the wild side". Which sadly means no mobile phone aghh!! so no Internet or other contact with the outside world unless you pay a kings ransom to those Rip Off merchants who provide the combined "bedside services" phone (1USD/min making or receiving), TV (20USD/part day) and Internet (I didn't dare ask how much).
Oh and don't you dare ask why the electronics (cheap PC board etc) of the bedside service was excempt from infection control, the minute you show that you know what you are talking about Hospital Admin get a "cobb on" and become "jobs worths" and say "rules are rules" or other such nonsense to that effect...
Anyway after the blood vessel burning very painfull IV antibiotics the one they have given me to take away is Oral Clarithromycin.
So if you know me personnaly please do not visit or at least please do not stand behind me or down wind of me or you are putting yourself at grave risk and please do not be alarmed if at times I sound lika a bad plumbing system or appear to hover they realy do rip through your digestive tract 8(