Where did words come from? The traditional view is that the relation between the sound of a word and its meaning is arbitrary. An alternative hypothesis, known as sound symbolism, holds that form-meaning correspondence is systematic. Numerous examples of sound symbolism exist across natural language phyla. Moreover, cross-linguistic similarities suggest that sound symbolism represents a language universal. For example, many unrelated languages affix an "ee" sound to words in order to emphasize size distinctions or express affection (e.g., look at the teeny weeny baby); other such phonetic universals are evident for object mass, color, brightness, and aggression. We hypothesize that sound symbolism reflects sensitivity to an ecological law (i.e., Hooke's Law) governing an inverse relation between object mass and acoustic resonance. In two experiments healthy adults showed high agreement in matching pure tones to color swatches and nonwords to novel objects as linear functions of frequency and luminance. These results support a degree of non-arbitrariness in integrating visual and auditory information. We discuss implications for sound symbolism as a factor underlying language evolution
