The Bouba-Kiki Phenomenon Tested via Schematic Drawings of Facial Expressions: Further Validation of the Internal Simulation Hypothesis.

Sound-shape associations involving consistent matching of nonsense words such as 'bouba' and 'kiki' with curved and angular shapes, respectively, have been replicated in several studies. The purpose of the current study was to examine the robustness of previously noted sound-shape associations when shape variations (angular and curvy) are embedded in schematic expressions of emotions (sad and happy). Results revealed consistent matching tendencies based on sound-emotion expression mapping irrespective of the particular shape of the expressions. We suggest that internally simulating the facial expressions/oral gestures may have played a significant role in driving the matching preferences.