Have any of these brain studies you mentioned RE scanning the brain as it reacts to the word "no" (and to other negative words and images) been tried with psychopathic subjects? I'm willing to bet that the brains of those with psychopathy react differently: probably there is a neutral response. I am fascinated with studies that can help tease apart the mechanisms, neural pathways or organic brain structure that may be inherent to psychopathy and distinct from the non-psychopathic brain.

I think my most dangerous (or perhaps sad) word is "senility."