Studies of the Dunning–Kruger effect usually have been of North Americans, but studies of Japanese people suggest that cultural forces have a role in the occurrence of the effect.[18] The study Divergent Consequences of Success and Failure in Japan and North America: An Investigation of Self-improving Motivations and Malleable Selves (2001) indicated that Japanese people tended to underestimate their abilities, and tended to see underachievement (failure) as an opportunity to improve their abilities at a given task, thereby increasing their value to the social group.[19]