At priceonomics, a discussion of a classic psychological experiment goes on to consider the social forces which encourage the work ethic:
…when South Korea and China were mired in poverty, Westerners described their people as hopelessly lazy, with a culture that did not value industriousness and taking initiative. As time has shown, however, this is not an innate inevitability but a reflection of economic realities. All these “lazy” people were perfectly willing to work hard, study long hours, and plan for the future, but only when opportunities existed and they trusted that hard work would pay off.
More at ‘What Marshmallows Tell Us About Silicon Valley’, and related material at ‘The Myth of the Lazy Poor’.