Jung's Duality Analysis

Jung’s (1923) idea about extroversion-introversion was the starting point for more scientific investigation in the personality traits domain in the early twentieth century. Jung proposed the “duality” in human personality. He distinguished two schools of thought in philosophy, namely idealists and realists and claimed that idealist consider the subject of perception as a base for knowledge while realists believe that the object of perception is the base of knowledge. Having studied the background of these schools of thought, Jung claimed that a comprise exists between philosophy and psychology in which realists are more extroverts while idealists are more introverts. He further differentiated these two distinctions by characteristics that identify

Factor analysis of the data led him to conclude that people can be divided into two groups of neurotic and normal. Later, Eysenck (1970) expended these two factors into five: extroversion-introversion, neuroticism, and psychoticism. With regard to his model, Griffiths (1991) claims that Eysenck’s model is favored amongst other possible models because it includes a well-defined classification in an unambiguous framework. In addition, it entails a theory that has produced an ample amount of research most of which have been supportive. Moreover, the instrument that is used to measure the model’s factors has been standardized in 35 different countries, some of which are located in Asia such as Singapore, Japan, Hong Kong, and India. He considers the hierarchic arrangement of behavior as the essence of Eysenck’s model that result in concepts of extroversion-introversion, psychotism-normality, and neuroticism-stability. Eysenck and Eysenck (1985) have claimed sufficient validity for Eysenck’s model; high test-retest reliability has been reported for this model (Griffiths,1991) that lends itself to the appropriateness of this model. On the other hand, Plomin (1976) criticized Eysenck’s theory and considered impulsivity and sociability as traits in their own

Thus, it is possible to anticipate an individual’s behavior in a given situation by knowledge of his/her personality. However, some psychologists like Mischel (1969) questioned the consistency of personality traits. He claimed that personality traits are not sufficient predictors of behavior in different situations. In spite of some disagreements on the consistency of behaviors and the capability of personality traits to determine them, it is generally accepted that traits are indicators of behavior. Farahani (1998) believes that four principles make up the cornerstones of trait theory of personality: 1) certain definite attributes or traits make up personality. 2) These trace are general to all people with a difference in their degree and extent. 3) Traits can be measured by identifying and examining the behavior that indicates them. 4) Personality is mainly determined biologically. According to Brunas-Wagstaff (1998), trait approach to personality assumes that personality traits are