In operant conditioning, organisms learn to associate a behaviour and its consequence. The target behaviour is followed by reinforcement or punishment to either strengthen or weaken it, so that the learner is more likely to exhibit the desired behaviour in the future.

The stimulus (either reinforcement or punishment) occurs soon after the response.

In classical conditioning, an unconditioned stimulus (such as food) is paired with a neutral stimulus (such as a bell). The neutral stimulus eventually becomes the conditioned stimulus, which brings about the conditioned response (salivation).

The stimulus usually occurs immediately before the response.

Psychologist B. F. Skinner saw that classical conditioning is limited to existing behaviours that are reflexively elicited, and it doesn't account for new behaviours such as riding a bike. He proposed a theory about how such behaviours come about.

Skinner believed that behaviour is motivated by the consequences we receive for the behaviour: the reinforcements and punishments. His idea that learning is the result of consequences is based on the law of effect, which was first proposed by psychologist Edward Thorndike.

According to the law of effect, behaviours that are followed by consequences that are satisfying to the organism are more likely to be repeated, and behaviours that are followed by unpleasant consequences are less likely to be repeated.

Essentially, if an organism does something that brings about a desired result, the organism is more likely to do it again. If an organism does something that does not bring about a desired result, the organism is less likely to do it again. An example of the law of effect is in employment.

One of the reasons (and often the main reason) we go to work is because we get paid to do so. If we stop getting paid, we will stop going—even if we love our job.

Working with Thorndike's law of effect as his foundation, Skinner began conducting scientific experiments on animals (mainly rats and pigeons) to determine how organisms learn through operant conditioning.

© Monash University FutureLearn 1

He placed these animals inside an operant conditioning chamber, which has come to be known as a 'Skinner box'. The box contains an input device like a lever, button or disk that the animal can activate for a food reward via the dispenser. Speakers and lights can be associated with certain behaviours. A recorder counts the number of responses made by the animal.

In operant conditioning, everyday words such as positive, negative, reinforcement, and punishment are in used in a specialised manner. Positive and negative do not mean good and bad.

Instead, positive means you are adding something, and negative means you are taking something away.

Reinforcement means you are increasing a behaviour, and punishment means you are decreasing a behaviour.

Reinforcement can be positive or negative, and punishment can also be positive or negative. All reinforcers (positive or negative) increase the likelihood of a behavioural response. All punishers (positive or negative) decrease the likelihood of a behavioural response.