I am a moderately experienced vim user, who is now beginning to use GNU emacs. At about the same time as I learned that Ctrl-p and Ctrl-n are the default for up and down in emacs, I also learned they are variants of k and j in normal mode in vim.
Does anyone know the origin of these shortcuts? I suppose that logically they come from p(revious) and n(ext), or maybe (u)p and (dow)n, but I am asking about what programme, system or standard they were part of. It seems unlikely that a couple of random emacs shortcuts were borrowed into vim, so their inclusion in both makes me think that they probably predate both emacs and vim.*
It's hard to find the answers to questions of keystrokes using Google, but interestingly they are not mentioned as "arrow keys" on the seemingly comprehensive Wikipedia article.
*Thanks to Thomas Dickey and Mark Plotnick who have pointed out in comments that the shortcuts in question are documented in 1984 vi (sic), and 1978 emacs reference works, but I think the question of common origin still stands.