It’s Not Always Black and White: How Color Enhances L1 and L2 Idiom Processing

Idioms are non-compositional expressions whose meanings transcend the literal interpretation of their components (e.g., “break the ice”). They highlight the psycholinguistic tension between direct retrieval and compositional semantic analysis. Past research suggests L1 readers rely more on direct retrieval and idiom familiarity, while L2 readers depend more on word-by-word compositional processing. Supporting this, studies show that disrupting an idiom’s canonical form impacts L1 readers more than L2 readers. This study explored the reverse effect by strengthening an idiom’s canonical form through font color. L1 and L2 readers read English sentences containing idiomatic/literal phrases, presented in colored/standard font, and judged whether the phrases made sense. Accuracy and reaction times were recorded. In L1 readers, idiom superiority (i.e., better performance for idioms than literal phrases) was driven by familiarity, with color coding enhancing this effect for more familiar idioms. In L2 readers, idiom superiority was influenced by both familiarity and decomposability, with color coding amplifying both effects. These findings suggest that L1 readers primarily rely on direct retrieval, whereas L2 readers utilize both direct retrieval and compositional processing, with color coding aiding idiomatic processing for both groups.