Math items about real-world content lower test-scores of students from families with low socioeconomic status.

In many countries, standardized math tests are important for achieving academic success. Here, we examine whether content of items, the story that explains a mathematical question, biases performance of low-SES students. In a large-scale cohort study of Trends in International Mathematics and Science Studies (TIMSS)-including data from 58 countries from students in grades 4 and 8 (N = 5501,165)-we examine whether item content that is more likely related to challenges for low-SES students (money, food, social relationships) improves their performance, compared with their average math performance. Results show that low-SES students scored lower on items with this specific content than expected based on an individual's average performance. The effect sizes are substantial: on average, the chance to answer correctly is 18% lower. From a hidden talents approach, these results are unexpected. However, they align with other theoretical frameworks such as scarcity mindset, providing new insights for fair testing.