In 2001, Vilayanur S. Ramachandran and Edward Hubbard asked American college undergraduates and Tamil speakers in India the same question.
And, in both groups, 95% to 98% selected the curvy shape as "Bouba" and the jagged one as "Kiki".
This phenomenon is called "Bouba-Kiki Effect".
It's suggesting that the human brain somehow attaches abstract meanings to the shapes and sounds in a consistent way.
