and this is not good news. Fear is still one of our survival tools, we need fear to assess situations, to avoid dangerous situations and not take unnecessary risks. Fear is also one of the emotions on the palette of the complex human emotions. If it is not paralyzing, irrational fear, why would you want to reduce the scale of emotions you can experience. Not only that, but fear is very closely linked to motivation. Why would you want to switch that 'engine' off?
"Experiements in animals demonstrate that sympathectomy may retard averse conditioning. (DiGusto and King, 1972), most likely because sympathectomy reduces fear."
Clinical Neuropsychology 2003