Desensitization from jokes is a common occurrence, one example would be how those in the military or other careers that train to take human life are almost always going to be more prone to dark humor involving death or killing, it makes those kind of ideas the normal so that when they need to cross that line it isn't as initially traumatic. Where as pedophiles joke about pedophilia so that normal people become used to hearing about it more as a joke rather than a serious issue. The problem is that makes it harder to tell who is actually joking and who will just claim its a joke when they get caught. I say we as all people should start publicly executing pedophiles immediately, and if you joke about that shit you're a suspect because it's not funny there is no reason a normal person would want to joke about something like that so you need to go get help from a licensed physician.