Envy is an emotion which occurs when a person lacks another's quality, skill, achievement, or possession and either desires it or wishes that the other lacked it.
Aristotle defined envy as pain at the sight of another's good fortune, stirred by "those who have what we ought to have". Bertrand Russell said that envy was one of the most potent causes of unhappiness. Recent research considered the conditions under which it occurs, how people deal with it, and whether it can inspire people to emulate those they envy.
Some languages, such as Dutch, distinguish between "benign envy" (benijden in Dutch) and "malicious envy" (afgunst), pointing to the possibility that there are two subtypes of envy. Research shows that malicious envy is an unpleasant emotion that causes the envious person to want to bring down the better-off even at their own cost, while benign envy involves recognition of others being better-off, but causes the person to aspire to be as good. Benign envy is still a negative emotion in the sense that it feels unpleasant. According to researchers, benign envy can provide emulation, improvement motivation, positive thoughts about the other person, and admiration. This type of envy, if dealt with correctly, can positively affect a person's future by motivating them to be a better person and to succeed.
There is some discussion on whether the subtypes should be seen as distinct forms of envy, as some argue that the action tendencies (to damage someone else's position for malicious envy and to improve one's own position for benign envy) are not part of how the emotion is defined, while others think action tendencies are an integral part of an emotion. Those that do not think subtypes of envy exist argue that the situation affects how envy leads to behavior; while those that do think subtypes exist think that the situation affects which subtype of envy is experienced.
Following Charles Darwin's 1859 book advancing the theory of evolution by natural selection, his 1872 work, The Expression of the Emotions in Man and Animals advanced the theory that there has been an evolution of emotion which developed in animals for the survival value emotions offer.