The birth of psychometrics

Modern psychology uses current psychometrics to explain some of its aspects, such as individual differences. But do we know How did this way of measuring the attributes of psychology arise??

Much of current psychometrics cannot be understood without attending to the background and historical origins of psychological tests and the measurement of intelligence. However, the first tests date back much earlier than you might think.

Approximately, the origin dates back to the year 2200 BC., when an emperor in China ordered that his government officials be examined every third year to determine whether they were adept at their position. With this, these tests continued to be carried out, being perfected over time. Still, it was not until the Han dynasty (200 AD) that these procedures were validated.

The beginning of psychometrics: experimental psychology

Experimental psychology began to flourish at the end of the 19th century in continental Europe and Great Britain.. It is at this moment when psychology begins to move away from the subjectivism and introspection that had been followed until now. Thus, human capabilities begin to be tested in laboratories and researchers begin to use objective procedures.

But who promoted these changes? Most of them were well-known psychologists such as Wundt, Galton, Cattell or Wissler. They showed that it was possible to expose the mind to scientific measurement. That is when the birth of psychometrics begins to be seen.

Psychometrics is an objective approach to the study of the human mind.

Wundt’s contributions

Willhelm Wundt (1832 – 1920) was a physiologist, psychologist and philosopher who founded what is known as the first psychological laboratory. This occurred in 1879 in Leipzig, Germany.

Wundt’s experiment was carried out with a type of thought meter. This instrument was a calibrated pendulum with needles protruding from each side. The pendulum swung back and forth, striking bells with the needles. According to a popular article, the observer’s task was to take note of the position of the pendulum when the bells rang.

Thus, Wundt considered that the difference between the observed position of the pendulum and the actual position could provide a means of determining the observer’s speed of thought. Despite the rudimentary, Wundt measured mental processes and thus recognized individual differences.

That is why it is important to highlight the study of individual differences and the influence of the first research on intelligence. as precursors of psychometrics.

The consolidation of psychometrics

It seems clear that the consolidation of psychometrics is reflected at the beginning of the psychological evaluation business. In 1895, the American Psychological Association (APA) formed a committee specialized in the new technology of measuring instruments. In 1899, the president of the APA called on psychologists to develop different tests. These had to have certain characteristics.

For his part, Cattell created the Psychological Corporation with the aim of producing tests in 1922. Twenty-five years later, in 1947, the Educational Testing Service (ETS), with the purpose of designing standardized tests to measure academic performance and aptitude.

The use of psychometric tests has made it possible to measure people’s performance in various contexts.

However, The creation of psychometric tests was not only limited to the field of education. Since, the US government of that time supported the psychological evaluation of its army in the First and Second World Wars through intelligence and personality scales; facts that contributed significantly to the development and consolidation of Psychometrics.

Some journals on psychometrics

In 1901, the magazine was founded Biometrika by Weldon, Galton and Pearson. In it, works related to biology and psychology were disseminated. Then, in 1936, Thorndike launched the magazine Psychometrika. Other notable magazines are:

Educational and Psychological Measurement.British Journal of Statistical Psychology.Journal of Mathematical Psychology.Journal of Educational Measurement.Multivariate Behavioral Research.Applied Psychological Measurement.Applied Measurement in Education.

Thus, the term “psychometry” is, currently, the most widespread and general term to refer to psychological measurement. It is the discipline that measures various psychic entities and is defined, according to Muñiz in his book The classical theory of testing, as “he set of methods, techniques and theories involved in the measurement of psychological variables».

As a summary, we can say that it is the science of measuring the “psychological” aspects of a person, such as knowledge, skills or personality.

Reliability and validity

Now, if the objective of psychometrics is the measurement of psychological constructs through tests, these constructs have to be represented in scores. To do this, experts use mathematical statistical analysis.

However, measuring a psychological construct is complicated, especially if we take into account the variables that may affect the subject during the test. For example, in an intelligence test, the results may be affected by exhaustion, sleep or hunger, experienced by the test taker. Well, the performance will not be the same if it is disturbed by any circumstance.

Consequently, The test taker’s score on the same test may vary depending on other variables. In order to ensure the reliability and validity of these tests, some theories emerged:

The first was the Test theory proposed by the psychologist Spearman at the beginning of the last century. It states that the true result of a test is obtained from the sum of the scores with the error variable. This variable type refers to the factors that can contaminate the result of a test. Subsequently, a new theory developed by the mathematician Rasch in the sixties emerged and which is currently taken as a reference in the design of tests. It is the so-called Item response theory; which establishes a probabilistic relationship between the trait that the item measures and the presence of that trait in the subject. Therefore, when developing the scales and tests, both the sample of the selected population and the value of the items are of vital importance.

The importance of psychometric tests

Thanks to psychometrics, psychology has instruments for measuring and quantifying psychological processes and cognitive abilities. Therefore, Its creation contributed to the consolidation of psychology as an empirical science. And, from its beginnings, psychometrics set itself the following objectives:

Establish a scientific methodology in the study of the mind. However, this has been a difficult goal to achieve, since the mind is difficult to measure. In addition, it is composed of other complex variables such as emotions, thoughts, judgments, among others. Identify the relationship between the external and internal stimuli that constitute the individuality and subjectivity of each person, through which one individual is distinguished from another.

Nowadays, psychometric tests are very useful and very popular in the field of Clinical Psychology and Educational Guidance.

For example, upon entering the school system, many candidates must pass psychometric tests that measure attitudes, vocations, personality traits, among others. Likewise, evaluations applied in the clinical setting can contribute to establishing a diagnosis, as is the case with depression and anxiety scales.

However, psychometric evaluation is not limited to these two fields; since it is also widely applied in other specialties, such as Forensic Psychology. In this context, the tests help the psychologist to detect any disorder in the accused and the results can even serve as evidence in judicial proceedings.

For its part, in the business field, Organizational psychologists use a variety of psychometric tests. to assess the skills and personality traits of candidates in personnel selection processes.

Likewise, in Sports Psychology, Psychometric tests are an excellent tool to measure the level of motivation and concentration of athletes. And, from there, make the relevant interventions to maintain or improve it.

Final considerations

Despite the difficulties of psychometrics in approaching a measurement of the mind, its contributions to the study of it have been relevant. Currently, there are various dimensions of the human being that have tests that allow them to be measured, such as memory, attention or language.

Psychometrics has made many advances in the field of psychology and has allowed us to study many variables that were previously considered inaccessible to objective measurement. Thanks to it, today we can identify multiple personality traits and understand the human mind more closely.

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