How did uhn-uh come to mean “no” and uh-huh come to mean “yes” in English?

Question

Pretty much the title. Also curious if other languages have similar non-word sounds for negation/affirmation.

In: Other

Answer 1

Uh-huh! has an upward inflection which is positive (yes).

Uh-uh has a downward inflection which is negative (no).

Generally these are used to communicate yes or no while someone else is speaking without interrupting them, so they can continue speaking. It’s a signal that you’re listening and communicating but expecting/ allowing them to continue. Speaking words requires the other person to switch from speaking to listening, but body language and grunts allow them to remain in speaking mode.