"The Bouba/Kiki Effect was first observed by German-American psychologist Wolfgang Köhler in 1929. In psychological experiments, first conducted on the island of Tenerife (in which the primary language is Spanish), Köhler showed forms similar to those shown above and asked participants which shape was called "takete" and which was called "baluba". Data suggested a strong preference to pair the jagged shape with "takete" and the rounded shape with "baluba". In 2001, Vilayanur S. Ramachandran and Edward Hubbard repeated Köhler's experiment using the words "kiki" and "bouba" and asked American college undergraduates and Tamil speakers in India "Which of these shapes is bouba and which is kiki?" In both the English and the Tamil speakers, 95% to 98% selected the curvy shape as "bouba" and the jagged one as "kiki", suggesting that the human brain is somehow able to extract abstract properties from the shapes and sounds. Recent work by Daphne Maurer and colleagues has shown that even children as young as 2.5 (too young to read) show this effect." Link.