Emotional sound symbolism: Languages rapidly signal valence via phonemes

Rapidly communicating the emotional valence of stimuli (i.e., negativity or positivity) is vital for averting dangers and acquiring rewards. We therefore hypothesized that human languages signal emotions via individual phonemes (emotional sound symbolism), and more specifically that the phonemes at the beginning of the word signal its valence, as this would maximize the receiver's time to respond adaptively. Analyzing approximately 37,000 words across five different languages (English, Spanish, Dutch, German, and Polish), we found emotional sound symbolism in all five languages, and within each language the first phoneme of a word predicted its valence better than subsequent phonemes. Moreover, given that averting danger is more urgent than acquiring rewards, we further hypothesized and demonstrated that phonemes that are uttered most rapidly tend to convey negativity rather than positivity. Thus, emotional sound symbolism is an adaptation providing an early warning system in human languages, analogous to other species' alarm calls.