White, W. A. (1916). Extroversion and introversion. In W. A. White, Mechanisms of character formation: An introduction to psychoanalysis (pp. 222-244). New York, NY, US: MacMillan Co.
http://dx.doi.org/10.1037/10656-010
Describes the classifications of extroversion and introversion in terms of libido and other psychoanalytic factors. The principle of the extroversion of the libido is that we project ourselves into the world and then rediscover ourselves in these projected symbols. Introversion is the opposite of extroversion. Instead of transferring the libido to an object without, the libido is turned within. After comparing these personality traits, the author concludes with a discussion of the concept of "individual" in psychology. (PsycINFO Database Record (c) 2016 APA, all rights reserved)