tourettes effects on polygraph test

I have a friend who had to take a polygraph test and he failed it by one point. He has tourettes and I was wondering if that could effect the results of a polygraph test. Please help.[/quote]

It could very much so, I believe. You have to remember too that polygraphs aren't conclusive and in court-cases, they are only taken as circumstantial evidence. Basically, if you're a nervous person, then you're more likely to fail one.