The Bilingual Creative Metaphor Task: A Psychometric Assessment of Metaphor Production in English and Spanish

Metaphors are frequently used during communication, offering insight into creativity and cognition through figurative language. In bilingual individuals, metaphor production is influenced by language proficiency and cultural context. However, there is no psychometrically validated test measuring metaphor production ability beyond English. This study develops a tool to assess bilingual metaphor production using simple prompts (e.g., “The small dog is...”) that require original metaphors (e.g., “a tiny tornado”). Using automatic item generation with GPT-4, we generated 100 metaphor prompts, evenly split between English and Spanish. A sample of 160 Spanish-English bilinguals on Prolific provided responses. To evaluate metaphor originality, 100 Spanish-English bilingual raters scored responses using a planned missing data design. We applied a graded response model (GRM) to compute factor scores for each item and person, yielding sufficient rater agreement and measurement precision across both languages (Factor Determinacy Index = .77, ranging from .58 to .87). To further develop the assessment tool, additional factor analysis identified the most effective items, forming a short test of 10 items per language. This research provides a foundation for developing reliable and valid assessments of bilingual metaphor production, advancing the understanding of creative language use in multilingual populations and supporting linguistic assessment applications.