This is really an anthropology question, but since there's no SE anthro forum and I already am a member of this forum, I'll ask it here.
What is the probability that a male is (I don't use "man" because the practice starts in high school) called by his first name or last name by his friends in given what generation he's in? How about women?
To make this question feasible, it's limited to baby boomers and later.
In my (Gen-X) experience, the first name/ last name classification doesn't change with age.
It's probably selection bias, but the only women I know who are often referred to by their last names are elite athletes.