Personality Psychology covers all dimensions to describe people (differencing one from the other) beyond intelligence and other performance measures.
Development towards a common model - the Big Five!
MBTI: a furthermore relelvant predecessor
From 16pf and NEO-PI to IPIP
C.G. Jung’s theory of types represents an early theory of personality psychology, but has little significance outside of his ‘schools’ today. On the other hand, this theory was operationalized in the MBTI by Katherine Myers and Isabel Briggs Myers. I still find the identification of subjects’ preferences (not types!) relevant for coaching or personal counseling. Clearly, the MBTI is outdated from the perspective of factorial personality psychology. Firstly, objectivity is lacking: both the test administrator and the test person can influence the results. On the other hand, it does lead to personal conversations, which is exactly what you want in personal counseling!
With Cattell’s 16pf, profiles are first developed for vacant positions, or other requirements. Then personality profiles are then compared with these. The factor structure, reliability, and validity of the 16pf are established and have been repeatedly confirmed. The NEO-PI test and the Five-Factor Model represent the next stage of test development, practicallyd confirming the structure of the 16pf. As a more recent development in factorial personality psychology, increasingly shorter, compact versions of tests based on the IPIP item collection have emerged. These, however, are limited to the five factors and omit the facets. The not-quite-as-short BFI-2 test represents a practical alternative.
Additional instruments and theories
The FPI: Start to clinical diagnostics
The Freiburg Personality Inventory is clearly based on the Big Five, and consequently, the NEO-PI-R, but also on the authors’ theoretical concepts and areas of expertise. The test comprises 138 items that are easy to understand and devoid of clinical jargon. Its design is reminiscent of factorial personality psychology; particularly noteworthy is it is representative of the general population and is subject to constant standardization and linguistic revision.
However, it has been criticized in the literature that the authors of the FPI initially failed to convey a comprehensive concept of personality and did not establish an explicit connection between the Big Five inventories and the 16pf.
The FPI: Start to clinical diagnostics
However, extensive validation studies and careful test maintenance followed. Correlations with or predictions of clinical findings have been extensively documented, even by scientist outside the author circle; for example, in eating disorders or asthma, and furthermore in psychiatric-forensic topics.
Beyond Factorial Personality Psychology
However, differential and personality psychology do not necessarily require factorial psychology. Other models have emerged from other empirical studies, not necessarily based on the criteria of factorial personality psychology, yet they are also not solely theory-driven, but empirical nonetheless.
Abraham Maslow
actually presents a theory of motivation (“needs”); however, biographical studies and observation of “self-actualizing” individuals (Einstein…) form his (rather weak) empirical basis.
George A. Kelly:
His repertory grid was the most important “test” from which he derived constructs.
Carl Rogers:
Originally, he was searching for clearly defined and measurable conditions for constructive personality change. Later, his recordings and analyses of therapy sessions became his empirical basis.
Other Tests: the Clifton Strengthsfinder (C)
The Clifton Strengthsfinder (R) is widely used in industry, although it is viewed rather critically by academics. It remains unclear whether the strengths represent ability, motivation, or personality traits. Furthermore, it is an ipsative method that avoids standardization. I am also critical of the test—which doesn’t hinder me from getting further insights about myself. I would even recommend it as a self-test. But by no means as an aptitude test, and not even in the context of leadership seminars.
My Seminar Differential and Personality Psychologie
I’m currently working over my lecture (with virtual and classroom sessions) at Charlotte Fresenius University in Wiesbaden. For me, the goal of the seminar is less about building knowledge. Rather, I’m primarily concerned with raising awareness. Even widely used tests often do not meet traditional standards, and should therefore be applied very sparingly—to the point of being absolute no-gos! My topic is therefore, first, to understand the development of personality models through exploratory factor analysis, and second, the subsequent test construction. The administration of tests and the evaluation of results by the students will serve as illustrations and activation in the seminar.