Look at the two figures that appear in the images. One of them is called Booba and the other is called Kiki.
Could you tell me which is which?
It is a psychological experiment devised by Wolfgang Köhler in which the subject is asked to say which of these figures is called Booba and which Kiki. 95% of people name it Kiki to the orange angular figure and Booba to the violet rounded figure.
It is believed that this has implications for language development so that the mechanism for naming objects would not be totally arbitrary.