Behaviourist Theories: Thorndike, Pavlov and Skinner

What Unites the Behaviourists

Behaviourism is among the most dominant of modern learning theories. Though the behaviourist view is comprehensive and includes a variety of specific thoughts, all of them suggest a common approach: learning happens through the development of connections between stimuli received and responses displayed by the learner. The three theorists below each proposed a specific mechanism for how that stimulus-response connection forms.

Thorndike’s Theory of Connectionism (Trial and Error)

Edward Lee Thorndike (1874–1949) was an American psychologist whose work on comparative psychology and the learning process led to the theory of connectionism, helping lay the scientific foundation for educational psychology. This theory is also known as trial-and-error learning or S-R Reinforcement theory.

Trial and error is a method of learning in which various responses are tentatively tried, and some discarded, until a solution is found. It’s a stimulus-response theory: specific responses (R) come to be linked with specific stimuli (S), and according to Thorndike, the chief way to effect an S-R connection is through trial and error — hence the name.

• Learning by trial and error is a gradual process.
• The learner must be definitely motivated for learning to occur.
• The learner makes random and variable responses.
• Some responses lead to the goal (satisfying responses); others don’t (annoying responses).
• As trials increase, annoying responses get eliminated while satisfying responses strengthen and repeat.
• The time taken to perform the task decreases with successive trials.

The underlying logic: when a connection is accompanied by pleasure, its strength increases; when accompanied by an annoying state of affairs, its strength decreases. In other words, an S-R connection strengthens when followed by pleasure and weakens when followed by displeasure — learning is said to have properly occurred when it results in satisfaction and the learner derives pleasure from it.

Pavlov’s Theory of Classical Conditioning

Ivan Petrovich Pavlov (1849–1936) was a Russian physiologist. Classical conditioning is a learning paradigm from the behavioural point of view, also known as conditioned response theory, respondent conditioning, or Pavlovian conditioning.

Classical conditioning is a form of learning in which two stimuli are presented together, and the response originally elicited by one comes to be elicited by the other. Conditioning means the modification of a natural response; Pavlov’s theory treats learning as habit formation, based on the principle of response association and substitution. It may be defined as a process in which a conditioned stimulus comes to elicit a response after being paired with an unconditioned stimulus.

In classical conditioning, a conditioned stimulus (CS) regularly precedes an unconditioned stimulus (US) that evokes an unconditioned response (UR). As a result of this pairing, the previously neutral stimulus begins to evoke a response of its own — this is what’s learned in classical conditioning. The response evoked by the conditioned stimulus after learning is called the conditioned response (CR).

Skinner’s Theory of Operant Conditioning

Burrhus Frederic Skinner (1904–1990) was an American psychologist, behaviourist, author, inventor, and social philosopher. Operant conditioning is a process of learning through which an organism learns to repeat behaviours that yield positive outcomes, or that let it avoid or escape negative outcomes. This theory is also known as Instrumental Conditioning or Reward Learning.

Skinner identified two types of reinforcers, and a reinforcer is any stimulus whose presentation or removal increases the chance a response will recur; reinforcement is the application or removal of a stimulus to strengthen a behaviour.

Schedules of Reinforcement

• Continuous Reinforcement Schedule
• Fixed Interval Reinforcement Schedule
• Fixed Ratio Reinforcement Schedule
• Variable Reinforcement Schedule

Comparing the Three Behaviourist Theories