ok What if I could get you a little script together, something that would take under a minute to perform for you.
You ask a person a series of questions then you ask another final question. The final question would be something like "what colour is grass" The person will 8/10 times answer wrong.
For me its more like 9/10
Let me know and i will post it. I dont really know if this is NLP as such
I'd be interested in seeing this script. If only to clarify what concept we are actually talking about.