I doubt many posters here have the experience I have regarding polygraphs. Albeit – my experience is from 30 years ago, when I was in law enforcement. I gained a level of respect for that technology then, and know it has only improved since.
Yes, they aren’t generally admissible in Criminal Court (some allow if both parties agree to it – seeing as how the defense can always argue their unreliability, and the prosecution can’t use the same argument if the defendant passes, they never are…). They are allowed in some Civil Courts, but again only with both parties’ acceptance, again the same reason they seldom are as in criminal courts).
Law enforcement would never present a case on the result of a poly, knowing it would be thrown out. But if allowed a poly could support a case. It’s main use was to help focus and prioritize an investigation. Like… If I was in a team investigating a rape and there were 5 suspects that stood out, all claiming innocence, I would ask them to take a poly. The focus of the team might then be on those that refused. Passing a poly didn’t automatically eliminate someone as a suspect, but very often lowered them down the "he-did-it" list.
Can you cheat on a poly? Well… yes… There are people that can repeatedly pass a polygraph test. Of course there are the sociopaths that don’t discern between right and wrong and therefore don’t show physical reaction to lying. But there are also people that learn how to cheat simply for the fun of it – or out of necessity. Keep in mind that in most test on reliability a random group of volunteers is selected and asked questions. The answers really have no consequences other than maybe shame. Like asking a college student if he has done drugs (as part of a survey) and requiring he lies… Its not as if he will get kicked out of school, his parents sent a note or whatever.
Now – replace that with a man who knows his marriage depends on passing the test… Put that completely different level of stress on him.
He can google all the tricks – place a tic in your shoe and press on it before answering, take a sedative, hum a tune, hold your breath… whatever… Only… the only person in that room that knows ALL the tricks is the operator.
Perhaps the biggest misconception about poly’s is thinking they are truth-tests. They aren’t… They don’t reveal the truth… What they can strongly indicate (so strongly that I would believe them…) is if the person being answered is being HONEST.
Although honesty and truth tend to go hand-in-hand this does not always apply.
Like if the person questioned truly believed the world was flat he would pass when replying with a no when asked if Earth was a sphere. He would be giving the wrong answer, but passing a lie-detector.
The wording of the questions is key. Like if there was financial and other evidence strongly supporting that he had visited five sex-workers he could pass with a "no" if asked "have you visited five sex-workers" because he truthfully met one of them twice. Or maybe because he met seven.
With that in mind you want an operator that is capable. The operator is IMHO even more important than whatever tools he uses. That operator will then define a few (you usually get 3-5) questions that are based on a yes or no factual answers. It won’t be "did you love her" because love is an emotion and relative, but rather "since xx.xx.xx [like the date of your marriage] have you had sex (as we defined sex before proceeding with this test] with any other person than your wife?"
Chances are one issue will be asked in two different questions, chances are there are several questions to establish a baseline.
Now… Since the test won’t give you the truth you need to appreciate what it will give you: Is your husband being honest.
To me this is even more important than the truth. With honesty the truth will eventually come out. If he isn’t honest that is telling you a lot more… It tells you that he is hiding something, that he’s still trying to get away with something and most of all – that he doesn’t TRUST you with the truth.
He doesn’t TRUST you with the truth…
THIS is the key factor if he fails. Not that he’s lysing, but that he doesn’t trust you with the truth.
I think poly’s can do so much good, but they need to have a purpose. That purpose is IMHO to establish where you are in reconciliation. If he passes then all that does is tell you that he’s been honest up to that point. What he has shared is therefore believable, and we have a higher expectation that he will be telling the truth as time goes on. He needs some credit for that.
If however he fails, it’s showing that he doesn’t trust you with the truth and/or that he doesn’t realize the seriousness of what he did. That in turn means that anything and everything he has already shared is tainted, and that anything he does share going on needs to be taken with extreme caution. That basically makes reconciling – an already hard task – near impossible.
Get that message across. That he NOW has the opportunity to be truthful and honest, and that honesty will pay dividends despite whatever pain the truth causes. At the very least, honesty opens up reconciliation.
But… ALSO make him realize that a failure will make it clear to you that he doesn’t trust you, and that in turn will make you think reconciling won’t happen, and will point you more towards divorce as your safe path out of infidelity.
And finally: Way too many times I have seen people drag their spouse to a poly and then doubt the result. Equally if they pass or fail.
Do not spend the time or money on a poly if you aren’t going to take note of the result. Make it clear both to yourself and especially to him what the consequences of a pass or fail would be.
IMHO this is a one-time chance for both of you to determine if he’s capable of reconciling or not.