How does the scientific study of individual variation benefit our understanding of normal gender and sexual development?

How does the scientific study of individual variation benefit our understanding of normal gender and sexual development?

Select one of these short articles on the guevodoces, eunuchs or castrati, respectively:

http://www.medicaldaily.com/guevedoces-dominican-republic-dont-grow-penises-until-age-12-what-we-learned-studying-353544

http://www.reuters.com/article/2009/03/16/us-china-eunuch-idUSTRE52E06H20090316

http://www.sciencedirect.com.ezproxy.uta.edu/science/article/pii/S0140673697101982

After consulting one of the articles given above, describe how the scientific study of the development of these particular individuals can further our knowledge of one of the following: gender identity; gender role behaviors; sexual orientation; sexual behaviors (and be sure to define your terms). How does the scientific study of individual variation benefit our understanding of normal gender and sexual development?