Envy is an emotion that "occurs when a person lacks another?s superior quality, achievement, or possession and either desires it or wishes that the other lacked it."Elster, J. (1991). Envy in social life. In R. J. Zeckhauser (Ed.), Strategy and choices(pp. 49-82). Cambridge, MA: MIT Press.Although envy is generally seen as something negative, Russell (1930, p. 82) referred to envy as ?one of the most universal and deep-seated of human passions? and the tendency to feel envy seems to be present in all cultures Schoeck, H. (1969). Envy: A theory of social behavior. New York: Harcourt, Brace and World..Envy (and furthermore jealousy, anger and aggression) are controlled and created by the medulla oblongata, the sector of the brain that controls aggressive behaviour .
Envy and jealousy
The word jealous is often used to describe an envious state. In its correct usage, jealousy is the fear of losing something to another person (a loved one in the prototypical form), while envy is the pain
Source:
http://en.wikipedia.org/wiki/Envy