Classical conditioning is a reflexive or automatic type of learning in which a stimulus acquires the capacity to evoke a response that was originally evoked by another stimulus.
- Ivan Pavlov (1849 – 1936)
- John B. Watson (1878 – 1958)
Several types of learning exist. The most basic form is associative learning, i.e., making a new association between events in the environment. There are two forms of associative learning: classical conditioning (made famous by Ivan Pavlov’s experiments with dogs) and operant conditioning.
In the early twentieth century, Russian physiologist Ivan Pavlov did Nobel prize-winning work on digestion. While studying the role of saliva in dogs’ digestive processes, he stumbled upon a phenomenon he labeled “psychic reflexes.” While an accidental discovery, he had the foresight to see the importance of it. Pavlov’s dogs, restrained in an experimental chamber, were presented with meat powder and they had their saliva collected via a surgically implanted tube in their saliva glands. Over time, he noticed that his dogs who begin salivation before the meat powder was even presented, whether it was by the presence of the handler or merely by a clicking noise produced by the device that distributed the meat powder.
In technical terms, the meat powder is considered an unconditioned stimulus (UCS) and the dog’s salivation is the unconditioned response (UCR). The bell is a neutral stimulus until the dog learns to associate the bell with food. Then the bell becomes a conditioned stimulus (CS) which produces the conditioned response (CR) of salivation after repeated pairings between the bell and food.
John B. Watson: Early Classical Conditioning with Humans
John B. Watson further extended Pavlov’s work and applied it to human beings. In 1921, Watson studied Albert, an 11 month old infant child. The goal of the study was to condition Albert to become afraid of a white rat by pairing the white rat with a very loud, jarring noise (UCS). At first, Albert showed no sign of fear when he was presented with rats, but once the rat was repeatedly paired with the loud noise (UCS), Albert developed a fear of rats. It could be said that the loud noise (UCS) induced fear (UCR). The implications of Watson’s experiment suggested that classical conditioning could cause some phobias in humans.
Additional Resources and References
- McSweeney and Murphy: The Wiley Blackwell Handbook of Operant and Classical Conditioning.: This brand new book contains an up-to-date, inclusive account of a core field of psychology research, with in-depth coverage of operant and classical conditioning theory, its applications, and current topics including behavioral economics.
- Mackintosh, N. J. (1983). Conditioning and associative learning (p. 316). Oxford: Clarendon Press.
- Pavlov, I. P., & Anrep, G. V. (2003). Conditioned reflexes. Courier Corporation.
- Watson, J. B. (2013). Behaviorism. Read Books Ltd.