Several cross-country examinations have found larger gender differences in Western countries. More lately, countries’ gender equality has been correlated with such gender differences, and it is sometimes argued that gender equality may paradoxically cause men and women to diverge. However, this gender-equality paradox has primarily been examined with this cross-country methodology, so it possible that other cultural differences, including differences in data quality, are more directly influential. Here, we reanalyze the results from multiple studies on the gender-equality paradox with country-level data available. We find that gender differences more strongly co-vary with cultural regions and data quality, and that controlling for cultural regions consistently causes the association with gender equality to drop to non-significance. Similarly, controlling for our data quality indicators strongly attenuates the paradox. Conversely, cultural regions and data quality explains gender differences beyond gender equality. Further, when controlling for language within Protestant Western countries, which are more culturally comparable, higher gender equality was associated with smaller gender differences in personality. These results challenge the claim that gender equality causes gender differences, suggests it is rather an example of a Simpson’s paradox, and indicates that the cross-cultural association is confounded with other cultural differences, and with data quality.