EXPERIMENTAL PSYCHOLOGY: HISTORY, METHOD AND CHARACTERISTICS - PSYCHOLOGY - 2025

The experimental psychology is a school of psychology that studies psychological phenomena using experimental methodology based on observation. It guarantees a scientific practice and implies the observation, manipulation and recording of the variables that affect a subject under study.

Experimental psychologists are interested in studying human behavior through the manipulation of variables in controllable situations and in unnatural environments that affect and influence behavior.

Gustav Theodor Fechner was one of the pioneers in the use of the experimental when trying to prove the relationship between physical and sensory magnitudes in 1860. However, it was in 1879 when Wilhelm Wundt, considered one of the founders of this trend, created the first laboratory of experimental psychology.

Definition of experimental psychology

This current of psychology defends the experimental method as the most suitable way to study human behavior.

Experimental psychology considers that psychological phenomena can be analyzed by experimental methods that consist of the observation, manipulation and recording of dependent, independent and strange variables that influence the object of study.

Many psychologists have used this method when carrying out their work to address multiple topics such as memory, learning, sensation, perception, motivation and development processes, among others.

Professionals who adopt this method want to know the behavior of a subject by manipulating variables in controlled environments. The contexts in which they are carried out are laboratories and instruments are used that guarantee exhaustive control and precision in their investigations.

The experiments can be carried out in humans but above all animals are used, since many times for ethical reasons people cannot be used to perform these tests. In addition, animals provide greater availability and control to researchers.

The most scientific part of psychology is unified with experimental psychology, because the use of its methodology guarantees a scientific practice through observation and experimentation, taking out the laws of behavior and mental processes.

History

With its emergence in the nineteenth century, psychology began to focus and become interested in the study of observable phenomena, thus giving rise to an empirical science, that is, based on observation and experience of events.

Later, experimental psychology would use rigorous methods and instruments to carry out the measurements in its investigations.

Experimental psychology emerged in Germany as a modern discipline with Wilhelm Wundt, who created the first experimental laboratory in 1879 and introduced a mathematical and experimental approach to research.

Wilhelm Wundt

Earlier in 1860 Gustav Theodor Fechner, a German psychologist, tried to prove and reason the link between physical and sensory magnitudes through experimental data in his work Elements of psychophysics.

Other authors who contributed to this growing science were Charles Bell, a British physiologist who investigated nerves; Ernst Heinrich Weber, a German physician considered one of its founders; and Oswald Külpe, main founder of the Würzburg School in Germany, among others.

The appearance of different schools was due to that tendency to experimentation of the time, whose purpose was to try to observe the degree of relationship between the biological and the psychological.

Among these schools is the Russian, which was interested in neurophysiology and which was started by Ivan Pavlov and Bechterev. Also functionalism, which aims to demonstrate the biological laws that define Watson's behavior and behaviorism.

Ivan Pavlov

In the twentieth century, behaviorism was the predominant school within psychology in general and especially in the United States. It is the branch of psychology that put mental phenomena aside within experimental psychology.

On the other hand, in Europe this was not the case, since psychology was influenced by authors such as Craik, Hick and Broadbent, who focused on topics such as attention, thought and memory, thus laying the foundations of cognitive psychology.

In the last half century, psychologists used multiple methods, not only focused and limited themselves to a strictly experimental approach.

Furthermore, the experimental method is used in many different fields within psychology such as social psychology and developmental psychology.

Experimental method

Example of a laboratory experiment

Experimental psychology considers that psychological phenomena can be studied through experimentation. It involves the observation, manipulation and recording of dependent, independent and strange variables that are the object of study, in order to describe and explain them based on their relationship with human behavior.

This method aims to identify the causes and evaluate the consequences, the researcher tries to find a causality between different variables.

On the one hand, there is the middle variable, which would act as an independent variable. The dependent would be the one that is related to the subject's behavior. Finally, all the external factors that influence this would be strange variables.

Experiments

The experiment is carried out in a controlled environment such as a laboratory, where the experimenter can manipulate variables and control those that may affect the others. Furthermore, you can thus form specific experimental groups of subjects according to your study interests.

The researcher is the one who creates the necessary conditions to be able to carry out the study and to apply the independent variable when he sees fit. Furthermore, with this method, the conditions can be repeated to check the results, as well as altering them to see the differences in the behavior to be studied between the different situations.

In this approach the experimenter manipulates the circumstances to control their increase or decrease, as well as their effect on the observed behaviors, in order to describe why a situation or change occurs.

Many times before conducting an investigation, pilot experiments are used, which are trials of the experiment to study some aspects of it. In addition, the experiments have another positive part, since when carried out in these controlled contexts they can be replicated by other researchers in future situations.

Characteristics of experimental research

Some of the characteristics of the experimental research are as follows:

-The subjects are arranged randomly forming equivalent groups, giving rise to a statistical equivalence so that the differences between the results are not due to initial differences between the groups of subjects.

-Existence of two or more groups or conditions to be able to carry out the comparison between them. The experiments cannot be carried out with a single group or condition to be compared.

-Management of an independent variable, in the form of different values ​​or circumstances. This direct manipulation is carried out to be able to observe the changes it produces in the dependent variables. Furthermore, the assignment of values ​​and conditions must be done by the researcher, since if this were not the case, it would not be considered a real experiment.

-Measure each dependent variable assigning numerical values ​​so that the result can be evaluated and thus speak of an experimental investigation.

-Have a design with which the influence of foreign variables can be controlled to the greatest extent and to prevent the results from being affected by them.

-Use inferential statistics to be able to make generalizations of the research to the population.

Phases of an experiment

Asch experiment

Statement of a problem

Choosing the problem to be investigated depends on the experimenter and what he wants to study, the research questions must be able to be solved through an experimental process.

Depending on the problem that arises, the methodological approach to be followed will be defined.

Hypothesis formulation

The hypotheses are the statements that are formulated and that anticipate the results that could be obtained from the investigation, relate at least two variables and must be described in empirical terms, being able to be observed and measurable.

Realization of a suitable design

With the design, the procedure or the investigator's work plan is reflected, indicating what is going to be done and how the study is going to be carried out, from the variables involved to the assignment of the subjects to the groups.

Data collection and analysis

For data collection there are multiple instruments that are valid and reliable, and techniques that will adapt better or worse and that will present advantages and disadvantages.

The analysis of the data is carried out by organizing the information so that it can be described, analyzed and explained.

Conclusions

In the conclusions, the fulfillment or not of the hypotheses, the limitations of the research work, the methodology that has been followed, implications for practice, generalization at the population level, as well as future lines of research are developed.

Objective and conditions of the experimental method

The objective of the experimental method in experimental psychology is to investigate the causal relationships between variables, that is, to analyze the changes that have occurred in the dependent variable (behavior) as a consequence of the different values ​​that the independent variable (external factor) presents.

The conditions for it to be possible to conclude that there is a relationship between variables are:

• The temporal contingency between variables. The cause variable, which would be the independent one, has to precede the consequence variable, which would be the dependent one.
• Covariation between variables. For there to be a relationship between the two, a change in the values ​​of one of them would imply a proportional change in the values ​​of the second.
• The correlation between variables should not be attributable to the effect of strange variables.

In short, the researcher must manipulate the independent variable, establish a temporal order between variables and must eliminate the effect that is exerted as a consequence of strange variables.

References

1. Experimental psychology. Recovered from ecured.cu.
2. Experimental psychology. Recovered from wikipedia.org.
3. Experimental psychology. Recovered from wikipedia.org.
4. Definition of experimental psychology. Recovered from definicion.de.
5. Definition, characteristics and objective of the experimental method. Recovered from psikipedia.com.