The law of equalization: what it is and what it explains in psychology

In the psychology of learning, numerous phenomena have been studied that have their theoretical basis in operant conditioning. Within it we find a concept called the law of equalization.

In this article we are going to see what the law of equalization consists of and how it was formulated.

• Related article: "Operant Conditioning: Main Concepts and Techniques"

Richard J. Herrnstein and operant conditioning

Operant conditioning, introduced by B. F. Skinner, is a form of learning through which a subject (human or animal) is more likely to repeat behaviors that carry positive consequences and less likely to repeat those that carry negative consequences.

The law of equalization It was initially formulated by Richard J. herrnstein (1961) because of an experiment with pigeons in variable interval concurrent programs (ie, programs where the criterion for administering the reinforcement is the variable time elapsed since the last reinforcer was presented). We will see later and in more detail what these types of programs consist of.

In this experiment, the pigeons were provided with two buttons in a Skinner box. Each button triggered different food reward rates. It was observed how the pigeons tended to peck the button that produced the highest food reward more frequently than the other button. Furthermore, they did so at a rate similar to the reward rate.

What is the law of equalization?

The law of equalization is an established quantitative relationship between relative rates of reinforcement and relative rates of response during the development of concurrent reinforcement schedules. This is limited to establishing that there is a correlation between behavior and the environment.

It is a law that has helped psychologists and behavior analysts to relate the behavior with the environment and develop equations that clearly show how these two would covary

The law of matching suggests that the response rate of a subject in an environment will be proportional to the amount or duration of positive reinforcement administered. Thus, the more positive reinforcement has been administered, the higher the response rate (and vice versa). Herrstein established this relative response rate as a law of conduct.

It applies with sufficient reliability when non-human subjects are exposed to concurrent variable-interval schedules, and their applicability in other situations is less clear, depending on the assumptions made and the details of the situation experimental.

Mechanisms and theories

The law of equalization It has been verified experimentally in different species., as well as in groups of subjects (not only individually).

It is a descriptive law of nature, and not a mechanistic law, since it does not explain the mechanisms responsible for the distribution of responses. Furthermore, it ignores when individual responses occur.

There are three types of theories that try to explain this law; are the following.

molar theories

They mainly explain sets of responses and you are associated with the total distribution of responses and the reinforcers that occur in the contexts in which you have to choose.

molecular theories

They focus on what happens at the level of individual responses and regard equalization as the net result of these individual choices.

breeding theories

They focus on features of behavior that are neither molar nor molecular, but something in between.

Choice behavior: concurrent programs

The law of equalization, as we have seen, arises as a result of concurrent programs that imply choice behavior. The simplest choice situation is based on two responses to choose from, each of which is followed by a reinforcer.

The concurrent programs occur at the same time (or concurrently), and the subject is free to switch from one response key to the other.

One of its generalizations is that it refers to situations of forced choice (concurrent programs of reason), where it is obligatory to choose one of the options. Thus, in forced choice programs, the way to comply with the law of equalization is to respond to only one alternative. For the subject, the most suitable strategy will be choose the best alternative and stick with it.

Deviations in the law of equalization

Sometimes the relative rates of response are not always exactly equal to the relative rates of reinforcement on each response alternative; this is due to other factors may be influencing.

So we are talking about two different situations: undermatching and overmatching. In undermatching, the best option is less chosen than the law of matching predicts. In overmatching, on the other hand, the best option is chosen more than what the law predicts.

The variables that determine the aforementioned deviations would be the following:

Use of different response topographies for each alternative

These imply different types of effort; for example flapping (alternative A) and pressing a key (alternative B).

The use of different reinforcers for each alternative

This means that an equivalence cannot be easily established.

Difficulty switching from one alternative to another

For example, let's think about subway transfers. Changing from one task to another involves some delay (difficulty or effort for the subject).

Bibliographic references:

• Herrnstein, R.J. (1961). Relative and absolute strength of responses as a function of frequency of reinforcement. Journal of the Experimental Analysis of Behavior, 4, 267–72.
• Domjan, M. (2009), Principles of learning and conduct, Madrid (Spain): Thomson