Extraversion and Libido in Jung and Cattell

Jung's Work on psychological types is recognized as one of his greatest achievements. It is natural to try to bring this work within the scope of experimental psychology, and indeed many such attempts have been made. However, it cannot be said that any of them have met with overwhelming success. In particular, the concept of extraversion/introversion has been made the basis of numerous questionnaires claiming to measure it, but the agreement of these different questionnaires is low.

Early research consisted of selecting features from Jung's descriptions of the typical introvert or extravert and transforming these features into questionnaire questions. Which features were selected as the most important depended on the views of the researcher. In fact, as Carrigan observes (1960, p. 330), the average correlation of different questionnaires evolved by these methods was only ·35. Such work has shown that the different features that Jung described as typical of the extravert or introvert are indeed inter-correlated, but not very highly. This in turn has cast doubt on the view that extraversion/introversion is a unitary dimension of personality.

Empirical investigation of the question of whether extraversion-introversion is a single dimension or a number of overlapping dimensions can proceed only by the methods of multivariate research. Such research measures a large number of different variables on each of a population of individuals, intercorrelates the variables and extracts a number of factors. If the original variables cover the personality sphere sufficiently comprehensively, the trait or traits related to introversion and extraversion will be found among the extracted factors. The results should demonstrate whether extra-version/introversion is a single factor, a number of correlated factors, or a number of quite independent factors.

Carrigan (1960) reviews over thirty such multivariate investigations of