The words emic and etic were coined by Kenneth L. Pike in 1954 (cf. Pike 1971) by truncation of terms like phonemic vs. phonetic. The pair applies not only to the sound level of language, but equally to the other levels of language and even to other domains of culture. In all of these domains, the idea of the contrast is the same:

• A certain phenomenon occurring in a particular culture (incl. language) may be taken as a token of something that tends to occur in cultures/languages. It is reidentified in diverse contexts essentially on the basis of its substantive properties. Example: aspirated voiceless plosive.
• The same phenomenon may play very different roles in each of those contexts:
  1. It may fulfill a well-defined function in one language/culture, by being in opposition (vulgo ‘contrast’) with other phenomena of the same system. Example: In Korean, the aspirated plosive constitutes a phonemic opposition with the unaspirated plosive.
  2. Again, it may be just a functionless concomitant of some other phenomenon. Example: In English, certain voiceless stops are automatically aspirated in certain contexts. This, however, is just a concomitant feature of some other feature, in this case voicelessness. It has no particular function in the system.

This shows that the same phenomenon may be viewed in two perspectives:

• If one merely identifies a certain phenomenon, taking it as something that has a universal basis, one is taking the etic perspective.
• If one takes the phenomenon as a functioning component of a particular system, one is taking the emic perspective.

Non-linguistic examples may be found, e.g., in the colors. For instance:

• In the etic perspective, the color ‘white’ is perceived as equal presence of light of all wave-lengths by every human eye.
• In the emic perspective, it is the color of purity, festivity and joy in most occidental cultures. It is the color of mourning in Chinese culture.

Reference

Pike, Kenneth L. 1971, Language in relation to a unified theory of the structure of human behavior. The Hague & Paris: Mouton (Janua Linguarum Series Maior, 24).