Infants' mapping was based on the combination of consonants and vowels in the words and neither consonants nor vowels alone sufficed for mapping.
Infants looked longer at incongruent pairings than at congruent pairings. Infants are able to differentiate between congruent trials (pairing an angular shape with 'kiki' or a curvy shape with 'bubu') and incongruent trials (pairing a curvy shape with 'kiki' or an angular shape with 'bubu'). More recent work by Ozturk and colleagues (2013) showed that even 4-month-old infants have the same sound–shape mapping biases as adults and toddlers.
ĭaphne Maurer and colleagues showed that even children as young as 2½ years old may show this preference. 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 groups, 95% to 98% selected the curvy shape as "bouba" and the jagged one as "kiki", suggesting that the human brain somehow attaches abstract meanings to the shapes and sounds in a consistent way. Although not explicitly stated, Köhler implies that there was a strong preference to pair the jagged shape with "takete" and the rounded shape with "baluba". In psychological experiments first conducted on the island of Tenerife (where the primary language is Spanish), Köhler showed forms similar to those shown at the right and asked participants which shape was called "takete" and which was called "baluba" ("maluma" in the 1947 version).
The bouba/kiki effect was first observed by German American psychologist Wolfgang Köhler in 1929. 1.5 Implications for understanding language.1.3 Contexts where the effect is smaller or absent.