Very interesting article, but to me it seems like there are other factors. At every job I have ever worked, there are people who either have or don't have what we call "work ethic". These employees in identical circumstances do tremendously different quality and quantity of work. How does science explain this? Also, can this be related to the classroom? What creates the desire to do well in school? Does that "A" or "100" really signify better work or better effort and motivate students, or is it just a meaningless letter and number?