The 4 differences between the ideographic and the nomothetic approach

Personality psychology deals with studying individual differences in personality over behavior. Very close to it we find differential psychology, which analyzes the causes of these differences.

In this article we will talk about the differences between idiographic and nomothetic approach, the two great approaches that these disciplines use to study personality. We will see how the idiographic focuses more on the individual person, and the nomothetic on traits common to individuals.

• Related article: "Differential Psychology: history, objectives and methods"

Approaches to personality psychology

To talk about the difference between idiographic and nomothetic approach, let's first see what each of these approaches, used to investigate personality, consists of:

1. Idiographic approach

The idiographic approach has the fundamental assumption that individuals are unique and unrepeatable beings. Its objective is to understand the human being individually, and is based on an intensive study of it (also individually).

The methodology that uses the idiographic approach consists of a selective examination of 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. For its part, the nomothetic approach is based on the basic assumption that individuals are similar to each other. Its objective 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. Idiotic approach

Later, a third approach appears, raised by Lamiell in 1997. It's about the idiotic approach, which part of the idiographic study to obtain nomothetic principles (generalizable). 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 idiographic and nomothetic approach is that the idiographic approach specializes in the unique features of the person; It is therefore a more "personalized" approach and centered on the individual himself. For its part, the nomothetic approach looks for 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" rather than "the law." Furthermore, this approach believes in a "clean slate" (in the sense that we are born without personality and that it is shaped by the environment), and places great importance on culture and society. The environment is important in shaping personalities and "creating" individuals.

On the other hand, there are other characteristics to consider.

1. Personality concept

Another difference between idiographic and nomothetic approach is that the idiographic approach has a dynamic and holistic personality concept, while the nomothetic understands the personality as something static and fragmented.

2. Theoretical approach

The theoretical approach allows authors or researchers to follow a theoretical line of work that guides 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 one of a general and differential personality psychology.

3. Kind of investigation

Another difference between 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 assessment

Regarding the assessment of personality, the idiographic approach is based on a subjective orientation and / or projective, while in the nomothetic approach the evaluation follows objective and / or psychometric.

Personality theories

Now that we have seen the difference between idiographic and nomothetic approach from different perspectives and focusing on different aspects, let's see which authors correspond to each approach.

1. Idiographic theories

Regarding authors who defend an idiographic approach centered on the individual, we find:

• 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

On the contrary, 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 5" or 5 personality factors (Big Five model).
• Gray: with his factorial-biological model of personality.

Bibliographic references:

• Pueyo, A. (1997). Differential Psychology Manual. Madrid: McGraw-Hill.
• Sánchez-Elvira, A. (2005). Introduction to the study of individual differences. Madrid: Ed. Sanz y Torres. 2nd Edition.