If,during a test conducted by your lawyer,you're asked "did you kill your wife?" (and you did) you don't care in the least if the polygraph indicates you're lying or not.Your lawyer isn't going to tell anyone.
Conversely,if the polygraph is being done at police headquarters you're going to be nervous.But when asked "did you kill your wife?" and the truth is that you didn't,neither your heart rate nor your respiration rate will be any higher than it was when you were asked "were you born in this country?"...whereas it would jump if you *did* kill her.
I'm certainly not sure if either of them did it.However,I strongly suspect that at least one of them know something about the crime.
And you watch...the story that the guy in Thailand is telling will collapse like a house of cards with a few weeks.
Wrong. A polygraph conducted in a stressful situation can absolutely be inaccurate, so there's NO reason in the world to think that the Ramseys not agreeing to one given by the police is a sign that they are guilty of anything.
Polygraphs are lousy lie detectors. Their main purpose is to intimidate people that think they work into confessing. I guarantee that anyone who is asked "Did you kill your wife?" will show a response whether they did it or not. Whether you are guilty or not, you know it is the "money" question and will respond as such. There are plenty of studies that show they are inaccurate when used in that manner, which is the most common type of polygraph testing.