Operant Conditioning
Operant conditioning is a type of learning in which voluntary behaviour is controlled or
conditioned by its consequences. In the above example, working hard at an essay in the
future has been conditioned by the rewarding consequence of getting a high mark for an
essay you have worked very hard on.
B.F. Skinner (1953) developed research methods for the experimental analysis of
behaviour, and stated that the principles of operant conditioning could be applied to both
human and animal behaviour. To study behaviour experimentally Skinner developed the
Skinner Box, an example of which is shown in the picture below. Typically a hungry rat
would be placed in the box and the experimenter would condition the animal to press a
lever. Because the lever pressing is not normal rat behaviour the first step is to shape the
behaviour. To do this the experimenter would reward (issue a pellet of food from the
dispenser) if the animal came close or touched the lever. Once this had been done a few
times the rat would have to actually press the lever to obtain food. Once the rat had learnt
that the food appeared as a consequence of pressing the lever, the rat would continue to
press the lever to receive food. Here the rat has operated on its environment to obtain a
reward; as a consequence lever-pressing has been learnt or conditioned as behaviour.
Reinforcement of an operant behaviour is the key to conditioning taking place. Without
reinforcement the rat may only press the lever by accident and not again. If you had not
gained an A grade for your essay, you would not have been reinforced and may, as a
consequence not work as hard in the future. Skinner derived the law of acquisition from
his basic experiment. This states that:
The strength of an operant behaviour increases when it is followed by a reinforcing
stimulus.
Notice in this definition that the reinforcer is also called a stimulus. So whilst
behaviourists talk about the strength or conditioning of a stimulus-response link, with
operant conditioning the stimulus (reinforcer) comes after the response. In classical
conditioning it is the other way around.
Reinforcement can be of 2 types- positive reinforcement and negative reinforcement. A
positive reinforcement occurs when a behaviour (response) is strengthened because it is
followed by a rewarding stimulus. This is generally how people normally think of
reinforcement – as positive and associated with inner mental states such as good,
satisfying, pleasurable. By contrast, a negative reinforcement occurs when a behaviour
(response) is strengthened because it is followed by the removal of an aversive (painful)
stimulus. The word ‘negative’ is often a source of confusion and often associated with
punishment. However, negative reinforcement is reinforcing of a behaviour and
punishment stops a behaviour. Negative reinforcement strengthens a response, and
punishment weakens or stops the response.
Negative reinforcement occurs in 2 ways, first by escape learning. Here a behaviour is
reinforced through escape from an aversive situation (a rat presses a lever in a Skinner
Box and terminates an electric shock). The second is by avoidance learning. Here a
potentially aversive situation (being grounded) is avoided by behaving in a certain way
(tidying up your bedroom).
Operant Conditioning
A type of learning in which
behaviour is determined by its
consequences
Reinforcement
Behaviour that is reinforced is
strengthened and more likely to
occur in the future
Positive Reinforcement
Involves the addition of
something – for example, food,
water, money, praise.
Punishment
Behaviour which is punished is
less likely to occur in the future
Negative Reinforcement
Involves the removal of
something – for example,
removal of threat, loud noise,
headache.