> I bet a lot of people crack and admit to things they were hoping to hide.
I bet a lot of people also crack and admit to things they never did. You're essentially using the stress associated with the "magic" of the polygraph to coerce a confession.
I've told this story in more depth in other places on this site - The one time in my life I have ever been accused of a crime was when the greenhouse I was working at was robbed. I went to the side of the greenhouse to fix a hole, and while I was gone, a lovely gentlemen decided to empty the cash register.
Flash forward to three police statements and one polygraph later.
My experience with polygraph tests is they are a way for police to coerce a confession. I "failed" the polygraph test, and "should come clean now so they would go easy on me." The problem is, I didn't do it, I didn't know who did it, and I didn't want to know who did it. I was 17, and they had no leads. Just an absolute joke.
I think the use of a polygraph in a situation like that is disgusting, but I also think it's very different compared to making it a requirement to work for FBI/CIA/NSA.
I bet a lot of people also crack and admit to things they never did. You're essentially using the stress associated with the "magic" of the polygraph to coerce a confession.