I once had to take a polygraph to be considered for a security clearance. For various reason I didn't want it - I didn't want to join the group of social misfits I knew who worked on classified projects, I didn't want project security telling me where I could go on vacation and with whom I could associate (no foreigners), plus I had a few ethical objections. But at the time I liked my job (lots of great unclassified tech work), wanted to keep it, and needed to go along with my bosses' desires to get me cleared.

The polygraph was administered by a strange guy from a three letter agency. I did the sphincter squeeze for every question. He said the test showed I was being deceptive. I thought that was the end of it and hoped my boss would leave me alone about it. But they called me back to do another one. This time I didn't do the sphincter squeeze. He said the test showed I was being deceptive. I don't know. I think the test just showed I didn't want to get a clearance.