The meanings, or implications of “boy,” “girl,” and “man” have shifted over the last several hundred years. “Man” used to mean human; so you’d see a sentence like, “There were two men of London: a woman and her son.”* But it came more and more to mean males only, so that “fisherman,” which might once have been as generic as “farmer” or “pioneer,” now brings to mind only males. The whole mankind = man = men way of writing encourages us to think only of males. So we get blinkered communications such as, “The pioneers went west with their possessions, wives, and children” because the writer thinks of pioneers as men and forgets that women and children were pioneers, too. We have to include women again if we want girls to grow up using the full scope of their abilities.
*Source, Words and Women by Casey Miller and Kate Swift
See also A Handbook of Non-sexist Writing and its reviews.
The Anglo-Saxon Chronicle described Ercongota, daughter of a seventh-century English king, as “a wonderful man.” No, she didn’t have a sex change. In her day, “man” was a true generic term meaning “person” or “human being.” Many older English writings do indeed use “man” in this sense. But, as this book explains, our language has changed, and this generic usage is no longer appropriate.
I grew up on “man = humankind” rhetoric so I can adjust to it but I now notice that it’s exclusionary.