U.S. English-speaking children and adults exhibit a “Gleam-Glum” sound symbolic effect linking phonemic vowel sounds with emotional valence

We tested a recently found sound symbolic effect, the gleam-glum effect, in which words with the [i]-phoneme (like “gleam”) are perceived as emotionally more positive than matched words with the [Ʌ]-phoneme (like “glum”). We extend prior work and verify this effect using a novel online pseudoword-to-scene matching task, testing U.S. English-speaking adults (n = 105) and 5- to 7-year-old children (n = 52). Participants heard pairs of matched [i]- versus [Ʌ]-monosyllabic pseudowords (e.g., “zeem” versus “zum”) and assigned them to cartoon scenes exhibiting contrasting emotional valence (positive versus negative). These results provide the first empirical evidence that the gleam-glum effect is robust across both young children and adults, with the effect magnitude somewhat less in children of this age compared to adults. Our findings confirm that the gleam-glum effect is already strong at an early age and holds promise of being an important mechanism for language comprehension, language use, and language learning.