Many prominent scientists and authors have on various occasions stated that in the future, the common people would be manipulated through chemicals in their food, water and injections, to suit the needs of the people that govern them.
http://www.corbettreport.com/articles/20090816_biochemical_manipulation.htm
One of the most famous examples of the idea of biochemical manipulation of the underclass was raised in Brave New World by Aldous Huxley in 1932. In Brave New World, the lower classes are exposed to a variety of chemicals before they are “born” that reduce their intelligence and adult height, and prepare them for the role they will fullfil when they grow up. Alcohol is used, lower castes receive less oxygen, and they are exposed to x-rays. The lower castes are also exposed to certain hormones to make them infertile. 70% of women are exposed in the womb to male hormones, and turned into so called “freemartins”, sterilized women who exhibit masculine behavior.