The main objectives of psychometry are to measure the variables that determine behavior and to compare different individuals in such dimensions. In the context of personality psychology these objectives are manifested fundamentally in the quantification of personality traits in order to predict behavior in a probabilistic way.

Since the beginning of the 20th century, a large number of assessment tests designed to evaluate personality have appeared. In this article we will describe the 5 main types of personality tests , which are mainly applied in academic and work contexts and, in the case of those measuring psychopathological characteristics, in clinical psychology.

Types of personality tests

The instruments used to assess personality are generally classified according to the methodological criteria that have determined their construction . In any case, most of these tests are based on the numerical measurement of personality constructs and on the comparison of the individual assessed with others.

In this way we find the rational personality tests, nowadays practically in disuse, the empirical ones (which are based on external criteria), the factorial ones, in which the items are grouped in traits, and the ones that combine more than one of the previous criteria; in this sense the tests created by Millon and by Cloninger are especially remarkable.

1. Rational or deductive

Rational or deductive tests are constructed from elements theoretically related to the variables to be measured . To do this, the authors of the test rely on hypothetical criteria and it is assumed that there is a correlation between these and the test items.

In 1914, shortly after the outbreak of World War I, American psychologist Robert Sessions Woodworth created the first personality assessment test. The “Woodsworth Personality Data Sheet” (PDS) was a psychopathological screening test that was intended to detect the predisposition to neurosis in soldiers.

The PDS consisted of 116 items, consisting of dichotomous (“Yes/No”) response questions such as “Do you have thoughts that keep you awake?” and “Do you have a strong desire to commit suicide? This was a test that was very susceptible to misrepresentation by men who wanted to avoid military service.

Rational personality tests are the least common of all the types, since they were immediately replaced by others based on empirical and factorial criteria , which give rise to more reliable and valid assessment instruments. However, as we will see below, some authors combine rational criteria with different ones.

2. Empirical (based on an external criterion)

The instruments of this class focus on assessing the correlation between the subject’s responses to the assessment items and a given external criterion ; thus, the test items should be useful to predict the relevant dimension.

In these cases, a group of subjects that show certain characteristics (such as a psychological disorder) are evaluated and the items are analyzed in order to choose those that are most representative of the criterion variable. From these, the definitive test is constructed, which is applied to other subjects in order to evaluate the same construct.

The best known empirical personality test is the Minnesota Multiphase Personality Inventory (MMPI) , developed by Starke R. Hathaway and Charnley McKinley in 1942. The MMPI is mainly used to assess the presence of personality traits relevant to psychopathology, such as paranoia, depression or social introversion.

3. Factorials or trait test

The personality factor tests have been the most successful. These tests evaluate various factors, that is, sets of items that correlate with each other; for example, the “Friendliness” factor would be composed of items that evaluate aspects such as openness, modesty, altruism or sensitivity to the needs of others.

The Raymond B. Cattell Personality Factor Questionnaire , better known as “16 FP”, has been one of the most widely used personality tests for a long time. This test evaluates 16 first-order (or basic) factors that are grouped into 4 broader ones: Defiance, Self-control and Stress.

However, at present the hegemonic personality test is the Costa and McCrae NEO-PI-R Inventory, which is also based on factorial criteria. This test is part of the model of the five major personality factors , built from research data and with the contributions of many different experts.

4. Mixed (with combined criteria)

Certain personality tests cannot be considered strictly rational, empirical or factorial, but have been constructed from a combination of criteria. One of the tests that best exemplifies this type of methodology is the Theodore Million Clinical Multiaxial Inventory (MCMI), from which different tests have been derived.

The MCMI was constructed using the three criteria we have discussed. First, this author relied on his own theory to choose a large number of items (rational strategy), then he selected a small part of these by comparing them with external criteria (empirical) and finally he identified the correlations between elements (factorial).