Personality psychology is concerned with studying individual personality differences in behavior. Very close to it we find differential psychology, which analyses the causes of these differences.
In this article we will talk about the differences between idiographic and nomothetic approach , the two main approaches used by these disciplines to study personality. We will see how the idiographic approach focuses more on the individual person, and the nomothetic approach on the traits common to individuals.
Approaches to Personality Psychology
To talk about the difference between the idiographic and nomothetic approach, let’s first see what each of these approaches consists of, used for research in personality:
1. Idiographic approach
The idiographic approach has the fundamental assumption that individuals are unique and unrepeatable beings . Its aim is to understand the human being individually, and it is based on an intensive study of the human being (also individually).
The methodology using the idiographic approach consists of a selective examination of a few subjects; it is a clinical method.
2. Nomothetic approach
Seeing the characteristics of the idiographic approach allows us to approach the difference between idiographic and nomothetic approach. The nomothetic approach is based on the basic assumption that individuals are similar to each other . The aim of this approach is to obtain general laws applicable to the population.
Its methodology is based on the examination of large samples of subjects, and uses correlational and experimental methods.
3. Idiothetical approach
A third approach appears later, proposed by Lamiell in 1997. It is the idiothetic approach, which starts from the idiographic study to obtain nomothetic (generalizable) principles . That is, it would be a combination of the two previous approaches.
Differences between the idiographic and nomothetic approach
As we have seen, the most important difference between the idiographic and nomothetic approach is that the idiographic approach specializes in the unique characteristics of the person; it is therefore a more “personalized” and individual-centered approach. The nomothetic approach, on the other hand, seeks the generalities of the personality, the traits common to all individuals, their similarities.
The idiographic approach understands generalizations as speculations without solid basis , and prefers “the case” instead of “the law”. Furthermore, this approach believes in the “clean slate” (in the sense that we are born without personality and that it is shaped by our environment), and attaches great importance to culture and society. The environment is important in shaping personalities and “creating” individuals.
On the other hand, there are other characteristics to be taken into account.
1. Concept of personality
Another difference between idiographic and nomothetic approach is that the idiographic approach has a dynamic and holistic concept of personality , while the nomothetic one understands personality as something static and fragmented.
2. Theoretical approach
The theoretical approach allows authors or researchers to follow a theoretical line of work to guide their studies. The theoretical approach is subjectivist in the idiographic approach and objectivist in the nomothetic approach .
Furthermore, the idiographic approach is more typical of an individual personality psychology, and the nomothetic approach of a general and differential personality psychology.
3. Type of research
Another difference between the idiographic and nomothetic approach is found in the type of research, since this is intensive in the case of the idiographic approach and extensive in the nomothetic approach .
4. Personality evaluation
As for personality assessment, the idiographic approach is based on a subjective and/or projective orientation, while in the nomothetic approach the assessment follows objective and/or psychometric methods.
Now that we have seen the difference between idiographic and nomothetic approach from different perspectives and focusing on different aspects, we will see which authors correspond to each approach .
1. Idiographic theories
As for authors who advocate an idiographic approach focused on the individual, we find a:
- Sigmund Freud: with his psychoanalytic theory of personality.
- Rogers: with his phenomenological theory.
- KELLY: With his theory of personal constructs.
- Gordon Allport: with his theory of personality.
2. Nomothetic theories
In contrast, in relation to authors who defend a nomothetic approach focused on the traits common to all individuals, we find
- Raymond B. Cattell: with his factorial-lexical personality theory.
- Eysenck: with his factorial-biological personality theory.
- Costa and McCrae: with their theory of the “Big Five” or 5 personality factors (Big Five model)
- Gray: with his factorial-biological model of personality.
- Pueyo, A. (1997). Manual de Psicología Diferencial. Madrid: McGraw-Hill.
- Sánchez-Elvira, A. (2005). Introduction to the study of individual differences. Madrid: Ed. Sanz y Torres. 2nd Edition.