This was the case even though the responses were done via an anonymous questionnaire. By contrast, the Americans (especially the men) showed a self-enhancing tendency when evaluating themselves when no reason for providing the evaluation was given. However, these cultural differences were eliminated when the participants were offered money for providing the correct self-evaluation. That is, the Japanese and the American groups both enhanced their self-evaluation ratings when offered a monetary awards. The findings show that the stereotypical differences in modesty between Japanese and American cultures were entirely dependent on context.
The authors believed that the results showed that modesty is a default reaction in the Japanese culture designed to avoid offending others. This default reaction was described as a social mandate that is advantageous to avoid being excluded from the group relations they encounter in everyday life. However, the study shows that default cultural behavior can be altered significantly with a monetary award because there is a strongly motivating factor present to override it.
Reference: Yamagishi, T., H. Hashimoto, Cook, K., Kiyonari, T., Shinada, M., Mifune, N., Inukai, K., Takagishi, H., Horita, Y., Li, Y. Modesty in self-presentation: A comparison between the USA and Japan. Asian Journal of Social Psychology, 15, 1, 60-68. The entire study can be read here.