how does mccllelland 's theory affect syudy skills?

Answer 1

Your question is touched upon in the site below:
http://dennislearningcenter.osu.edu/references/stACH%20paper%20-JCSD%20new%20data-r.htm

This paper cites two publications by D. C. McClelland. You might want to take a look at them.

McClelland, D. C. (1965). Toward a theory of motive acquisition. American Psychologist, 20(5), 321-333.

McClelland, D. C. (1979). Increasing achievement motivation. Boston: McBer.