Gaius I strongly disagree.
I make a lot of jokes, and I mean a lot. The thing though is that I don't purposely make jokes to make people laugh, infact I can argue that I'm not actually trying to make jokes at all, but what I say may come out like that. Anyway, I make people laugh all the time, and people tell me how funny I am all the time. It happens to be that I'm able to find something funny in every conversation I have with someone/people, even when having a serious conversation. I don't do it on purpose, something funny just pops up in my mind while I'm talking to someone and I say it, and we both laugh. Then again what is funny to you is not funny to everyone. I never seem to find comedians funny at all. I've watched countless comedic shows and till this day I can't find one that makes me giggle, so "being funny" is subjective.
Being funny/making jokes in my opinion has nothing to do with type, but rather with character.