Describe Eysenck’s type theory of personality, the different personality types, his personality scale, what the scale measures and its limitations.

For the purpose of psychological research, Eysenck devised a theory of personality which would enable splitting people into different personality types. Eysenck aimed to classify people either as extroverts, introverts or neurotics. Extroverts were defined as outgoing with a strong tendency to socialize and interact with the outside world. Introverts were characterized as more shy with a preference to do things alone. Neurotics were described as having low self-confidence, changing moods and apprehension towards new situations. Determination of an individual’s personality type was achieved with the help of a personality scale devised by Eysenck which was called “The Eysenck Personality Inventory” (EPI). The scale involved the individual answering two sets of questions with yes/no answers. First, questions relating to extroversion and introversion levels were answered. Then the second set of questions, aiming to determine how stable or unstable the individual was, were answered. The results of the individual’s answers classified him or her as one of four personality types: stable extrovert, unstable extrovert, stable introvert, unstable introvert.
Even though Eysenck’s personality inventory has been used widely in Psychology research in the past and is still used today, several limitations need to be considered. First, the EPI has been criticized for being too simplistic. Personality is a very complex issue and the EPI reduces personality to only four categories. Second, due to the EPI relying on participants to answer questions as its sole form of assessment, it is dependent on participants answering honestly. Finally, the EPI implies that one classification is valid for one person for all their life. This view fails to consider that personality may change throughout an individual’s life span.