Which of these shapes is a bouba, and which is a kiki? And what does this have to do with the evolution of language?
Imagine they were real-world objects and you had to give them a name – one has to be called ‘bouba’, and the other has to be called ‘kiki’. Which name would you assign to which object?
The bouba/kiki effect finds its origins in the work of the German psychologist Wolfgang Köhler in 1929. Köhler showed people shapes similar to the ones above, and asked them which was a ‘takete’ and which was a ‘malumba’.
The visual shape of the object – either round or spiky – is linked to the shape that our lips make when we say that corresponding word – either open and rounded, or narrow and wide. In turn, this is linked to the way that our tongue moves in order to generate the word itself; kiki requires you to make a ‘sharp’ movement of the tongue on your palate, where as bouba involves a more ‘rounded’ movement. These similarities all increase the likelihood that bouba will be linked to the rounded object, and kiki to the sharper, spikier object.