The Idiographic and Nomothetic Approaches to the Study of Personality

The idiographic and nomothetic models understand personality from rather different points of view. Discover the main distinctions between them in the following article.

Written and verified by the psychologist Ebiezer López.

Last update: 29 August, 2023

The idiographic and the nomothetic are two different perspectives that coexist in the study of personality. Although the objective of both is to describe this construct, there are essential differences. Knowing how to differentiate between these two approaches means it’s possible to have a more precise idea of what the study of personality implies. Next, we’ll explore the differences between the idiographic and nomothetic approaches to personality.

Research suggests that there are many definitions of personality. They vary depending on the particular theory. But, as a rule, experts agree that personality consists of a set of qualities that condition behavior in certain circumstances. For example, we might speak of an explosive personality when describing someone who reacts impulsively to the slightest provocation.

Among the characteristics that make up the personality are thoughts, emotions, attitudes, and ways of acting.

Studying personality is complex as it’s a construct that’s configured by different factors. Therefore, each theorist has a different vision of the concept and the elements involved. Despite this, they tend to agree that there are certain constants in personality models. The two most important perspectives are idiographic and nomothetic.

Before detailing the differences between the idiographic and nomothetic approaches to personality, we’ll explore both separately. This will give you a better idea of how they can be distinguished from each other.

The idiographic approach to personality

The idiographic model of personality considers that no human being is 100 percent identical to another. In other words, we all possess certain qualities that no one else in the world has. Consequently, every one of us is unique. As a result, every individual’s personality is an unrepeatable configuration and must be evaluated as such.

When researchers conduct idiographic studies, they enlist small groups of participants. Their objective is to determine what differentiates one person from another. They don’t seek to elaborate general laws to explain behavior.

The nomothetic approach to personality

Contrary to the above approach, the nomothetic perspective suggests that we all share certain qualities. Consequently, researchers conduct studies with large samples of populations, in order to find common traits between them. As a result, general laws can be established that explain how human beings behave.

1. Quantitative research vs. qualitative research

Researchers using the nomothetic approach conduct research by taking large samples of populations and analyzing their traits with statistical methods. They employ psychometric tests to obtain numerical data to interpret. Thus, they define specific norms in certain groups and see if they can be applied to other similar populations.

On the other hand, the idiographic approach leans toward qualitative research, which focuses on describing phenomena. Idiographic researchers conduct studies with a single or a few cases and don’t use psychometric instruments. Instead, they use tools such as the biographical method to obtain as much detail as possible about an individual.

2. Static personality vs. dynamic personality

Nomothetic researchers claim that personality consists of more or less stable traits or pillars. This means that it doesn’t tend to vary much over time. It’s also fragmented which means that it’s made up of several elements that can be analyzed separately.

On the contrary, idiographic researchers see personality as the result of dynamic processes. They believe that it changes over time and therefore needs to be studied intensively. They also view personality as holistic and believe it can’t be divided, even for study purposes.

3. Objectivity vs. subjectivity

Another difference between the idiographic and nomothetic approaches to personality lies in their theoretical approaches. Nomothetic authors choose to conduct studies based on objectivity. In other words, they draw their data from an objective reality that doesn’t depend on what an individual thinks or believes.

However, in idiographic studies, subjectivity has a greater weight. In fact, it’s not the objective world that matters, but the internal reality of each individual. This is the only way to describe the characteristics that make them unique.

Scientific research

Seeing their differences in this way, one can think of the idiographic and nomothetic as rivals to each other. But, in scientific practice, they tend to be complementary to understanding a particular phenomenon in depth.

A study conducted by Ellison et al (2020) better illustrates the aforementioned fact. The researchers wanted to investigate the dynamic connections between select features of BPD (anger, impulsivity, and identity disturbance) and anxiety-related experiences.

They analyzed data from 42 psychiatric patients suffering from BPD or anxiety disorders (without BPD). The symptoms differed from individual to individual. Therefore, the research suggested that connections between BPD and anxiety symptoms aren’t dependent on diagnoses and tend to be idiographic.

The idiothetic approach

The idiothetic approach arises from the combination of the idiographic and the nomothetic. It takes the characteristic elements of each model and conducts more complex and rich investigations. In an idiothetic study, thanks to intensive individual evaluation, laws or common patterns are described.

Finally, it’s clear that the differences between the idiographic and nomothetic approaches to personality aren’t mutually exclusive. In fact, both models can be used to complement the data obtained and provide a broad perspective of personality.