People Worldwide Instinctively Link Nonsense Sounds to Shapes They've Never Seen

More detail

One of the foundational principles of linguistics is that the sounds of a word have no inherent relationship to its meaning — a concept called the arbitrariness of the sign. The word "dog" sounds nothing like a dog; neither does "chien" or "Hund." But a striking and persistent exception keeps showing up in experiments. When people are shown a rounded blobby shape and a sharp spiky shape alongside the made-up words "bouba" and "kiki," the vast majority point to the blob for "bouba" and the spikes for "kiki." A 2021 study tested 917 speakers of 25 different languages using 10 distinct writing systems — including Georgian, Thai, Korean, and isiZulu — and found that 72 percent made the expected pairing. The effect even appears in children who have not yet learned to read, and in communities with limited exposure to Western culture. Researchers believe the link is driven by the shape of the mouth when pronouncing each word: "bouba" requires rounded lips and tongue movements, while "kiki" uses sharp, quick, high-pitched articulations. This cross-sensory association challenges the arbitrariness assumption and has implications for understanding how language may have first evolved from gesture and vocalization.