Operant Conditioning

By the 1920s, the most important B.F. Skinner’s theory of operant conditioning got spread and  J.B. Watson had left academic psychology and proposing new forms of learning other than classical conditioning.

Skinner’s theory of operant conditioning was based on the work of Thorndike (1905). Edward Thorndike studied learning in animals using a puzzle box to propose the theory known as the ‘Law of Effect’

B.F. Skinner (1938) coined the term operant conditioning; it means roughly changing behavior by the use of reinforcement.

Reinforcement

Reinforcement is given after the desired response. Skinner identified three types of responses or operant that can follow a behavior

Neutral operants: responses from the environment that neither increase nor decrease the probability of a behavior being repeated.

Reinforces Responses from the environment that increase the probability of a behavior being repeated.

Reinforces can be either positive or negative.

Punishers: Responses from the environment that decrease the likelihood of a behavior being repeated. Punishment weakens behavior.

For example, if when you were younger you tried smoking at school, and the chief consequence was that you got in with the crowd you always wanted to hang out with, you would have been positively reinforced (i.e. rewarded) and would be likely to repeat the behavior.

1. Positive Reinforcement

• Skinner showed how positive reinforcement worked by placing a hungry rat in his Skinner box. The box contained a lever on the side and as the rat moved about the box it would accidentally knock the lever.
• Immediately it did so a food pellet would drop into a container next to the lever. The rats quickly learned to go straight to the lever after a few times of being put in the box. The consequence of receiving food if they pressed the lever ensured that they would repeat the action again and again.
• Positive reinforcement strengthens a behavior by providing a consequence an individual finds rewarding. For example, if your teacher gives you £5 each time you complete your homework (i.e. a reward) you will be more likely to repeat this behavior in the future, thus strengthening the behavior of completing your homework.

2. Negative Reinforcement

• The removal of an unpleasant reinforcer can also strengthen behavior. This is known as negative reinforcement because it is the removal of an adverse stimulus that is ‘rewarding’ to the animal or person.
• Negative reinforcement strengthens behavior because it stops or removes an unpleasant experience.
• For example, if you do not complete your homework, you give your teacher £5. You will complete your homework to avoid paying £5, thus strengthening the behavior of completing your homework.
• In fact, Skinner even taught the rats to avoid the electric current by turning on a light just before the electric current came on.

Punishment (weakens behavior)

Punishment is defined as the opposite of reinforcement since it is designed to weaken or eliminate a response rather than increase it. It is an aversive event that decreases the behavior that it follows.

• Like reinforcement, punishment can work either by directly applying an unpleasant stimulus like a shock after a response or by removing a potentially rewarding stimulus, for instance, deducting someone’s pocket money to punish undesirable behavior.
• Note: It is not always easy to distinguish between punishment and negative reinforcement.
• There are many problems with using punishment, such as Punished behavior is not forgotten, it’s suppressed – behavior returns when punishment is no longer present.