I noticed something interesting. Latin doesn't have a direct word for yes.
Sic - as follows
in another way
in such a way
etiam- and also,
in addition/as well
truly, to be sure
And so on.
These words for "yes" seems to be like something people adopted in later years. While in the beginning there was no word for "yes".
This implies that the people who spoke latin in that time did not need the word "yes". Which in turn implies that they could discern whether someone agreed, without it.
I assume that this is something we have forgotten, and we are remembering slowly,