The term reinforce means to strengthen, and is used in psychology to refer to any stimuli which strengthens or increases the probability of a specific response. For example, if you want your dog to sit on command, you may give him a treat every time he sits for you. The dog will eventually come to understand that sitting when told to will result in a treat. This treat is reinforcing because dogs like treats.
This is a simple description of a reinforcer (the treat), which increases the response (sitting). We all apply reinforcers everyday, most of the time without even realizing we are doing it. You may tell your child "good job" after he or she cleans their room; perhaps you tell your partner how good he or she look when they dress up; or maybe you got a raise at work after doing a great job on a project. All of these things increase the probability that the same response will be repeated.
There are four types of reinforcement: positive, negative, punishment, and extinction. We’ll discuss each of these and give examples.
The examples above describe what is referred to as positive reinforcement. Think of it as adding something in order to increase a response. For example, adding a treat will increase the response of sitting; adding praise will increase the chances of your child cleaning his or her room. The most common types of positive reinforcement or praise and rewards, and most of us have experienced this as both the giver and receiver.
Think of negative reinforcement as taking something away in order to increase a response. Taking away a toy until your son picks up his room, or withholding payment until a job is complete are examples of this. Basically, you want to remove or withhold something of value in order to increase a certain response or behavior.
Punishment (Positive Punishment)
What most people refer to punishment is typically positive punishment. This is when something aversive is added in order to decrease a behavior. The most common example of this is disciplining (e.g. berating) a child for misbehaving. The reason we do this is because the child begins to associate being punished with the negative behavior. The punishment is not liked and therefore to avoid it, he or she will stop behaving in that manner.
When you remove something in order to decrease a behavior, this is called negative punishment. You are taking something away so that a response or unwanted behavior is decreased. Putting a child in a time-out until they can decrease their aggressive behavior, for instance, is an example of a negative punishment. You're removing interactions with others in order to decrease the unwanted behavior.
Research has found positive reinforcement is the most powerful of any of these. Adding a positive to increase a response not only works better, but allows both parties to focus on the positive aspects of the situation. Punishment, when applied immediately following the negative behavior can be effective, but problems may result when it is not applied consistently. Punishment can also invoke other negative emotional responses, such as anger and resentment.
Know that we understand the four types of reinforcement, we need to understand how and when these are applied (Ferster & Skinner, 1957). For example, do we apply the positive reinforcement every time a child does something positive? Do we punish a child every time he does something negative? To answer these questions, you need to understand the schedules of reinforcement.
Applying one of the four types of reinforcement every time the behavior occurs (getting a raise after every successful project or getting spanked after every negative behavior) is called a Continuous Schedule. Its continuous because the application occurs after every project, behavior, etc. This is the best approach when using punishment. Inconsistencies in the punishment of children often results in confusion and resentment. A problem with this schedule is that we are not always present when a behavior occurs or may not be able to apply the punishment.
There are two types of continuous schedules:
Fixed Ratio. A fixed ratio schedule refers to applying the reinforcement after a specific number of behaviors. Spanking a child if you have to ask him three times to clean his room is an example. The problem is that the child (or anyone for that matter) will begin to realize that he can get away with two requests before he has to act. Therefore, the behavior does not tend to change until right before the preset number.
Fixed Interval. Applying the reinforcer after a specific amount of time is referred to as a fixed interval schedule. An example might be getting a raise every year and not in between. A major problem with this schedule is that people tend to improve their performance right before the time period expires so as to "look good" when the review comes around.
When reinforcement is applied on an irregular basis, they are called variable schedules.
Variable Ratio. This refers to applying a reinforcer after a variable number of responses. Variable ratio schedules have been found to work best under many circumstances and knowing an example will explain why. Imagine walking into a casino and heading for the slot machines. After the third coin you put in, you get two back. Two more and you get three back. Another five coins and you receive two more back. How difficult is it to stop playing?
Variable Interval. Reinforcing someone after a variable amount of time is the final schedule. If you have a boss who checks your work periodically, you understand the power of this schedule. Because you don’t know when the next ‘check-up’ might come, you have to be working hard at all times in order to be ready.
In this sense, the variable schedules are more powerful and result in more consistent behaviors. This may not be as true for punishment since consistency in the application is so important, but for all other types of reinforcement they tend to result in stronger responses.
Thanks for A. Kent Van Cleave, Jr., Ph.D. for comments on this article.