There’s a professor who’s done a study about the origins and use of the word “dude”: the interesting part?
Kiesling says in the fall edition of American Speech that the word derives its power from something he calls cool solidarity — an effortless kinship that’s not too intimate.
Cool solidarity is especially important to young men who are under social pressure to be close with other young men, but not enough to be suspected as gay.
Anecdotally, men were the predominant users of the word, but women sometimes call each other dudes.
Less frequently, men will call women dudes and vice versa. But that comes with some rules, according to self-reporting from students in a 2002 language and gender class included in the paper.
“Men report that they use dude with women with whom they are close friends, but not with women with whom they are intimate,” according to the study.
Huh. Not sure if I’d go with the universal “all guys” thing there.