B.F    Skinner (Mar 1904-Aug 1990)

An Americal psychologist behaviourist, he was the Edgar Pierce Professor of Psychology at Harvard University. Skinner (1948) is regarded as the father of operant conditioning, but his work has based on Thorndike (1898) Law of effect. Skinner introduced a new term Reinforcement. That is, behaviour which is reinforced tends to be repeated (i.e., strengthened); behaviour which is not reinforced tends to die-out or be extinguished. (i.e. weakened).

Skinner studied operant conditioning by conducting experiment using rats which he placed in a ‘Skinner box’ similar to Thorndike’s puzzle box as shown in Fig 7

Skinner identified three types of responses or operants that can follow behaviour

 •   Neutral operants

 •   Reinforcers

 •   Punishers

Positive reinforcement

 Skinner showed how positive reinforcement worked by placing a hungry rat in the above 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 rat 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 behaviour by providing a consequence an individal finds rewarding.

 

Negative reinforcement

 Negative reinforcement strengthens behaviour because it stops or removes an unpleasant experience. The removal of an unpleasant reinforcer can also strengthen behaviour. In fact Skinner even taught the rate by subjecting them in the box with an unpleasant electric current which caused it some discomfort. The rats soon learnt to press the lever when the light came on because they know that this would stop the electric current being switched ON.

 

Punishment

 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 behaviour that follows.

 Punished behaviour creates fear and does not necessarily guide towards desired behaviour - reinforcement tells you what to do, punishment only tells you what not to do.