Cultural influences on number preferences: Christmas and grading systems

People consistently prefer numbers associated with themselves (e.g., birth dates) over other numbers. We argue that such number preferences are also shaped by cultural influences, such as customs regarding the day on which Christmas is celebrated and customs regarding ranking of numerals used in national school's grading system. Across 6 different countries (N = 657), the day on which Christmas is celebrated had an influence on the preference for the numbers 24 vs. 25, and numbers used for better grades were uniformly rated better than numbers used for poorer grades. If grading did not involve numbers (e.g., letters A to F), then no effect appeared.