I once took a class in college on argumentation and debate. Part of the course consisted of making debate cards. Debate cards were basically your evidence (by qualified authors of course..) to back up your argument. Well I had wondered what the debate cards would look like for somebody who frequently engages in ad hominem attacks during their arguments. Ad hominem is something you probably see a lot, for example:

Bob and Harry are at the gym. Bob is bench pressing and does so with a slight arch. Harry argues that arching is stupid and that benching is bad for his shoulders. Harry then explains to Bob that benching with an arch, while squeezing your shoulder blades in and keeping your elbows tucked takes pressure off the shoulders and engages the triceps more, allowing you to push more weight. Harry doesn’t like being wrong and has nothing to back up his “arching is stupid and bad for your shoulders” argument so he just tells Bob to shut up and that he smells like poop so who cares.

As you can see, instead of providing evidence to back up his “arching is stupid” argument, Harry just gets angry and attacks Bob personally.