What is a personality test?

Written by
Cornelia Kirschke
Personality tests measure personality
ID37 is a trait-based personality test that captures the full spectrum of an individual’s personality
We see personality tests being used in a wide range of contexts, from recruitment to team-building to leadership training, coaching and therapy. There are also countless personality tests available online that people can take on their own. Offering a valuable means of gaining insight into how people think, feel and behave, these tests benefit individuals, teams and organizations alike. At the same time, however, tests are often used to categorize people into “types,” a process that lacks any scientific basis. In fact, typology-based tests have several drawbacks. Based on an outdated, wholly unproven theory, they simplify the diversity of human personalities and under-acknowledge the complexity of each individual. We therefore recommend the use of trait-based personality tests that differentiate by assessing individual traits in specific contexts. In this article, we explain the concept of a personality test and explore the distinctions between type-based and trait-based tests. 

What is a personality test?

People are unique in many ways. When it comes to accurately capturing an individual's personality, personality tests are the preferred method because they objectively assess personality traits. In short, they measure personality.

Personality tests are standardized procedures used in psychology to systematically capture individual variations in experiences and behavior. These tests aim to identify and describe personality traits, motivations or preferences through different assessment methods. These methods include self-assessment tests, such as the ID37 Personality Test, where individuals rate descriptive statements about themselves across scales. Other methods used may involve responding to questionnaires or engaging in discussions with a test administrator, particularly in the case of children.

The primary objective of these tests is to enhance our understanding of people’s thought processes, emotions and actions, thus enabling predictions about their potential behaviors in specific situations. The practical applications of personality tests span diverse fields, including career counseling, staff development and selection, coaching and therapy. The outcomes of a personality test are inherently value-neutral.  This is because these tests do not measure cognitive abilities, such as those assessed by language or intelligence tests.

Are personality tests scientifically valid?  

There are different types of personality tests, and making the right choice will depend on the objectives pursued.  Particularly in professional settings, it’s important to seek guidance from experts in order to determine the precise aspects to be measured and ensure that the appropriate instrument or methodology is selected. The foundation of a scientific personality test lies in its ability to meet essential criteria of objectivity, validity and reliability. It’s imperative that psychological methods not only deliver consistent and trustworthy data but also accurately measure the traits they claim to assess.

Tests developed by scientific research are transparent about their adherence to these quality standards. Tests that lack a comprehensive manual with clearly defined indicators may not be scientifically valid. The ID37 personality test meets these quality criteria, incorporating a standardization procedure that compares an individual test result with those of a broader population. The ID37 manual can be downloaded from the ID37 website.

What distinguishes type-based from trait-based personality tests?  

Type-based and trait-based personality tests represent two distinct approaches to identifying and assessing personalities. Although both find applications in the business world, they offer notably contrasting insights.

Type-based personality tests, also referred to as typology tests, categorize individuals into a limited number of predetermined “types,” each characterized by specific traits or behaviors. This approach implies that vastly different individuals can be grouped under the same personality type, suggesting that they are very similar to each other. At the same time, it creates the impression that people of different types are very different from each other. These tests often do not account for mixed personality types and may oversimplify by assigning labels like “the Rationalist” or “the Melancholic.” Many typology tests lack a basis in established theories or scientific validation, which raises questions about their credibility.

Trait-based personality tests, often referred to as the dimensional approach in personality assessment, focuses on assessing individual differences rather than categorizing individuals into distinct types. These tests measure differences among individuals across various dimensions, such as motives. In addition, this kind of testing provides a continuous measure in its response options, which means that responses for each dimension can range from (very) low to (very) high. This yields an enormous amount of information that allows for a more precise and accurate analysis of the individual. Trait-based personality tests offer a differentiated picture of a personality that is reflected in a personality profile. These profiles typically rely on empirically validated personality models and can demonstrate adherence to rigorous scientific quality standards.

Characteristics of type-based personality tests

Examples of type-based personality tests include the Myers-Briggs Type Indicator (MBTI), DISC, Insights Discovery and 16 Personalities.

User advantages

  • Simplified identification with a personality type
  • Encourages self-reflection: Users are prompted to reflect on their thoughts, feelings and behavior

User disadvantages

  • Simplification and distortion: The practice of categorizing people into fixed personality types oversimplifies the complex nature of individuals. It fails to account for the diversity within each type and disregards mixed types. Categorizing people as types perpetuates stereotypes and stigmatization.
  • Lack of scientific validity: Many of the questionnaires used are often not based in empirical science, and they rarely provide information regarding compliance with the quality standards of science.
  • Constraint: Pigeonholing people into a single type can hinder their potential for personal growth.
  • Limited predictive power: Predictions about an individual’s behavior and responses in different situations cannot be reliably made.

Characteristics of trait-based personality tests

Examples of trait-based personality tests include the ID37 personality assessment, Big Five personality test, Reiss Motivation Profile, BIP, Hogan and NEO-FFI.

User advantages

  • Differentiation: Recognizing an individual's uniqueness through their distinct characteristics across various dimensions of personality.
  • Predictive power: A precise analysis of personality allows predictions to be made about behavior and reactions in different situations.
  • Development potential: The personality profile aids in identifying personal potentials for individual life planning and growth.

User disadvantages

  • Complexity: Engaging with the personality profile may require a significant time investment and, in some cases, expert knowledge to fully comprehend and harness its potential.

What the experts recommend: Use trait-based testing

Prominent scientists and experts, including Prof. Joseph Devlin, Professor of Cognitive Neuroscience, reject the notion of personality types, citing their lack of empirical validity (see also: Freudenstein, J. P., Strauch, C., Mussel, P., & Ziegler, M. (2019) They instead advocate for the use of trait-based personality tests in cases where they are backed by scientific evidence.

This is because trait-based tests can capture and explain the complexity and diverse nature of human personality. By contrast, type-based personality tests should be avoided in a professional environment.

Among trait-based tests, only those with a high degree of differentiation, such as the ID37 personality test, enable users to identify their potential and resources, which they can then leverage for their personal growth. Featuring 16 dimensions aligned with 16 life motives, the ID37 Personality Test stands out for its remarkable capacity to distinguish individuals from one another. Compared to other trait-based personality models, such as the Big Five model, ID37’s personality test provides a more comprehensive description of a person’s personality. As a standardized testing procedure, individual ID37 personality test results can be compared with other test results. This makes ID37 particularly suitable for use in organizations, for example with teams within companies.

For further information on the development of the ID37 personality test by the team led by Prof. Dr. Christoph Kemper and Dr. Jan Dörendahl as well as insights into the science of personality psychology and its relevance within the professional work environment, see our publication, "Personality Assessment with ID37".

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