Why do we often associate “higher” sounding vowels (E, A, I) with sharp edges and “lower” sounding vowels (O, U) with round/dull/circular edges?

Question

A wiki on the topic https://en.m.wikipedia.org/wiki/Bouba/kiki_effect

In: Other

Answer 1

Does this really need an explanation? Just look at the shapes of the letters in your title lol.