History of Personality Measurement

Psychometrics is primarily concerned with the study of differences between individuals and between groups of individuals. It involves two major research tasks, namely: (i) the construction of instruments and

procedures for measurement; and (ii) the development and refinement of theoretical approaches to measurement.

Personality has been defined as the “dynamic organisation within the individual of those psychophysical systems that determine his characteristic behaviour and thought” and throughout history has been a subject of intensive investigation and interest. Personality theory can trace its roots back to the days of the Greek physician Hippocrates (450 BC) rates who transferred thought away from the spiritual side of human behaviour and theorized that every body has four fluids or humors (blood, phlegm, yellow bile and black bile) that fundamentally affected behaviour or personality.

Galen (190 AD) added to this theory, believing that predominance of any one humor as outlined by Hippocrates would cause specific temperaments. He also believed that a healthy body was the direct result of a balance in the ratio of these four body temperaments.

While this school of thought proceeded to influence both psychology and medicine for centuries, it was Wilhelm Wundt (1879) who first made the clear distinction between human body and personality. Wundt stated that the four temperaments represented the four dimensions of the human personality, paving the way for the development of the numerous personality assessment methods that were to follow.
These included:

Name Approach Types
Adicke, 1879 four different view points to look at the world innovative traditional
doctrinaire sceptical
Eduard Spranger, 1905 four attitudes towards ethical values artistic religious
theoretic economic
Hugo Munsterberg, 1913
Devised survey for executives of different organizations, researching qualities they wanted to see in their employees. These were listed as the first personality test to help employers make the best hiring decisions
Henry C. Link, 1919 Defines ideal personality testing machine – data received and sorts candidates for suitable jobs

Ernst Kretchmer, 1920 Theory of four character styles hypomanic, depressive
hyperesthetic anaesthetic
Erich Fromm Four human orientations exploitative hoarding
receptive marketing
Carl Jung, 1922 Four personality types based on human preferences
Myers Briggs /Katherine Briggs, 1958 Application of Jung’s theory, based on four questions a. Preferred source of your energy? (Internal or external) b. Preferred source of perception? (Senses or Intuition)
c. Preferred decision making system? (On logics or feelings) d. Preferred life style? (ordered or adaptable)

Since the development of these initial personality theories much work has been undertaken by psychometricians to develop characteristic selection approaches that are used to explore the correlation between responses to questions about typical behaviours and statements concerning the trait or characteristic being examined. The methodology used to extract this information from the individual has inevitably led to the increase in popularity of the personality trait or psychometric questionnaire which is now in widespread use across various industries to support ongoing training and development as well as the initial recruitment and selection of staff.
The construction of personality trait questionnaires begins initially with the understanding that there are a pre-defined set of personality traits that can be measured and scored on a recognised scale. While Eysenck’s research identified three major underlying personality factors, the more recent studies agree that that Costa & McCrae’s “big five framework” are appropriate for describing the majority of human personality. By subdividing the big 5 into intermediary variables composed of differing personality traits it is possible to see how individual traits will produce commonality in responses to differing situations.
• Extroversion: the extent to which a person is outgoing
• Neuroticism: the extent to which a person is emotionally unstable
• Openness to experience: the extent to which a person is imaginative & flexible
• Conscientiousness: the extent to which a person is well-organised
• Agreeableness: the extent to which a person is good-natured

This trait theory measurement attempts to avoid all subjective measurement of personality and move towards and objective measurement based on a generalised response or behaviour to a certain situation, known as a nomothetic approach. This may involve single-trait or multiple trait scales within an individual questionnaire. Factor analysis is then used to determine the minimum number of factors that account for variance and could contribute to a higher level factor within the individual questionnaire.

Cattell’s personality type model developed in 1957 seeks to identify the relatively few dimensions that account for all differences in personality, reducing the trait list of over 4500 labels developed by Allport into 35 trait –name-clusters and eventually into 16 high order factors. These 16 source traits are deemed to be the origin or result in the interaction of all traits and habitual responses. Critics of Cattell state that the inter-correlation between the model’s dimensions would suggest that there are fewer than the minimum dimensions that Cattell stated.
The reliability (extent to which measurement procedure is free from unsystematic error) of any questionnaire will be based upon the process by which it was constructed and depends heavily upon the accurate selection of appropriate traits and factors. In addition, the validity (the extent to which the measurement tool actually assesses what it was designed to measure) of any personality profiling questionnaire will be highly dependent upon the accuracy of research and the quality of the administration of the assessment. There is also the business of defining what a trait or competency is
Further to this, there is criticism, captured by David McClellan that “’the trouble with psychometric tests is that they tell you what a person can do if asked to do it but they don’t tell you what he does do” This lack of practical application, coupled with the hugely negative impacts of a poorly designed or administered test have led to a number of critics voicing opinion around some of he major company, career and business decisions founded on the basis of a single assessment.
The psychological personality trait profile provides an overview of the preferred behaviour that comes almost unconsciously to most people. This is the behaviour that they are comfortable with and can sustain without consciously or actively applying it and it is key to understand this behaviour, especially when considering an individual for a senior position within an organisation. Behavioural flexibility and its measurement is equally important as the ability to be able to adapt to situations that the individual may not naturally be comfortable in may will be a frequent occurrence in a commercial environment.

The recruitment process in every organisation is a costly process – to fill a typical £30,000 position can take up to 16 weeks and cost in the region of £5000 , in addition, once in position ability to perform with a certain role can dramatically impact the profitability of an organisation. Personality profiling improves the efficiency of the recruitment process identifying the most suitable candidates early on in the recruitment process thereby reducing the time and money spent on unsuitable candidates. In addition, by having further, objective information about a candidate, the employer is able to make a more complete and informed decision regarding selection, benchmarking candidates consistently and objectively with a deeper knowledge of the individual’s general propensity to act in a particular way in a given situation.
Personality profiling and the use of trait-based questionnaires can provide valuable insight into the most likely behavioural responses of an individual to external stimuli and a range of situations, determining the most appropriate candidate for a particular position in a recruitment situation.

In summary, while profiling will never provide the definitive answer to how an individual will react in a given situation it can provide a prediction based on “signs or indicators of likely behaviour” . By utilising this information effectively it is possible to identify a more likely ‘fit’ between individual and role, thereby reducing the likelihood of staff turnover and incongruence between candidate and role. When used in conjunction with other selection and recruitment methods (interviews, aptitude tests, group situational analysis), personality profiling can provide a useful and effective complement to support the costly and time consuming process of personnel selection within an organisation. Therefore, with the assurance design and administration is both professional and effective, personality trait questionnaires can add significant value and provide additional insight to assist businesses in developing and retaining their most important and influential asset – their people.