Previous studies on the association between numerical parity and gender have yielded conflicting results and discussions regarding its universality. Some research conducted in the United States suggested that individuals associate odd numbers with male and even numbers with female. In contrast, a study in the United Arab Emirates found that the pattern of association varied between male and female participants. Furthermore, earlier studies insisted that the association is a cross-cultural phenomenon, whereas later studies argued for its cultural specificity. However, the evidence remains inconclusive regarding both claims due to a lack of data from other cultural areas, including Japan and East Asia. Thus, the present study conducted the Implicit Association Test (IAT) with native Japanese participants to measure how they classify odd/even numbers and male/female face image stimuli. The results showed that neither male nor female participants associated numerical parity with gender, as indicated by the D-score. These findings are inconsistent with the claims of previous research. Methodological considerations and directions for future research are also discussed.
