David Grossman, a military psychologist, wrote a well researched and very knowledgeable study of what armies must do to alter a person's mindset so that he (the soldier) can actually kill in time of war or necessity ("On Killing"). In other words, killing does not come naturally to new soldiers. On the same topic, re hanging, I once read a book about English hangmen over a period of two/three centuries. I'm sorry, I can't recall the name of this volume but I do distinctly remember that the problems included not only selecting the right rope for the size of body to be hanged but also tying the noose properly while taking into consideration the length of the drop. Serious mishaps occurred. Most of all, it became very difficult to find hangmen because the job, over a period of time, became dreadful and, as a result, more than a few hangmen became alcoholics, outcasts and some committed suicide. I do not know if this situation and behaviour are culture specific, however. I do not know, for instance, if the same holds true in Iran where the the "guilty" party's neck is tied to a huge crane and moved gradually upwards (with his family forced to look on) so that he strangles slowly to death. I have viewed this on YouTube in illustrations of articles by the Gatestone Institute. Gruesome. I have also read that in Saudi Arabia the normal means of death is by the sword. I have seen photos of the swordsmen. One swordsman was quoted as saying that he had no problem returning home after a beheading and then enjoying a good dinner with his family. He was quite proud of his work.