Children, as they develop, learn to repeat the skills that work. The thing with anger is that for most people, most of the time, it doesn't work. Eventually anger gets discarded along with all the other bad coping ideas. Or else maybe you just get tired and decide "Who cares anyway?"

I said "for most people, most of the time" because there are times when anger serves a purpose. I have known a lot of "Ned Flanders"-types (For those of you sans TV, it is a pop culture reference to a character from the popular Fox Show "The Simpsons") who really need to get angry, if even just once in their life, to get the "gall-diddly-arned" stick out of there rectum. Also, like humor, a burst of raw anger can be an incredibly powerful weapon when focused (can something be raw and focused? I dunno). It can really get a persons attention. It is definitely a tool that is most effective when used sparingly.