Edward Thorndike
Edward Lee Thorndike (1874–1949) was an American psychologist known for his experiments on how animals learn and for the Law of Effect, one of the most important ideas in the psychology of learning.[1][2]
Life and studies
Thorndike went to Harvard University in 1896, where he studied with William James and researched learning in chicks. He then moved to Columbia University to work with James McKeen Cattell.[1] Some of his early experiments with cats were carried out in the basement of William James's house.[3] His results were published in 1898 as "Animal Intelligence: An Experimental Study of the Associative Processes in Animals".[1]
Puzzle boxes
At the time, many writers used stories about clever pets as evidence of animal intelligence. Thorndike rejected such anecdotes. Instead he studied many animals, repeated his experiments and controlled the animals' past experience and surroundings.[4] He was the first to investigate systematically how an animal's behaviour changes with experience.[5]
A hungry cat, dog or chicken was placed in a "puzzle box" from which it could escape to reach food by a simple act, such as pulling a loop of cord, pressing a lever or stepping on a platform. Thorndike recorded how long each escape took.[4][5] At first the cats behaved randomly and made the correct response by accident; over many trials the unsuccessful actions dropped away.[6] One cat's escape time fell from 160 seconds on the first trial to 7 seconds on the 24th.[2]
Thorndike called this "trial and accidental success", now usually known as trial-and-error learning. Because he thought the animals learned connections between what they saw in the box and their escape responses, his theory is called connectionism.[6] He found no evidence that the animals learned by reasoning, or by watching another cat solve the box.[7] In 1911 he argued that psychology should study animal behaviour rather than consciousness, and should extend this approach to humans.[1]
Laws of learning
From the puzzle box studies Thorndike drew two principles:[7]
- The Law of Effect: "Of several responses made to the same situation, those which are accompanied or closely followed by satisfaction to the animal … will, other things being equal, be more firmly connected with the situation".[3] Responses that fail are weakened and disappear.[7]
- The Law of Exercise: a connection between a situation and a response grows stronger with practice.[7]
In modern psychology the phrase "satisfying state of affairs" has been replaced by the word reinforcer.[2]
Criticism and influence
The critic Wesley Mills criticised Thorndike's method, complaining that he "placed cats in boxes only 20 × 15 × 12 inches and then expected them to act naturally".[8] Thorndike replied by asking what a "natural" environment could mean.[7] Despite such criticism, the laboratory method took hold.[8]
The Law of Effect closely resembles B. F. Skinner's later idea of operant conditioning, and Skinner acknowledged his debt to Thorndike.[7] Although his work helped shape behaviourism, Thorndike "did not consider himself a behaviorist".[3]
See also
== References ==
- ↑ 1.0 1.1 1.2 1.3 Pickren, Wade E.; Rutherford, Alexandra (2010). A History of Modern Psychology in Context. Hoboken, New Jersey: John Wiley & Sons. p. 58. ISBN 978-0-470-27609-9. Retrieved 2026-10-23.
- ↑ 2.0 2.1 2.2 Mazur, James E. (2017). Learning and Behavior (8th ed.). New York: Routledge. p. 115. ISBN 978-1-138-68994-7. Retrieved 2026-10-23.
- ↑ 3.0 3.1 3.2 Staddon, John (2014). The New Behaviorism (2nd ed.). New York: Psychology Press. p. 19. ISBN 978-1-84872-688-8. Retrieved 2026-10-23.
- ↑ 4.0 4.1 Goodwin, C. James (2015). A History of Modern Psychology (5th ed.). Hoboken, NJ: John Wiley & Sons, Inc. p. 198. ISBN 978-1-118-83375-9. Retrieved 2026-10-23.
- ↑ 5.0 5.1 Mazur, James E. (2017). Learning and Behavior (8th ed.). New York: Routledge. p. 114. ISBN 978-1-138-68994-7. Retrieved 2026-10-23.
- ↑ 6.0 6.1 Goodwin, C. James (2015). A History of Modern Psychology (5th ed.). Hoboken, NJ: John Wiley & Sons, Inc. p. 199. ISBN 978-1-118-83375-9. Retrieved 2026-10-23.
- ↑ 7.0 7.1 7.2 7.3 7.4 7.5 Goodwin, C. James (2015). A History of Modern Psychology (5th ed.). Hoboken, NJ: John Wiley & Sons, Inc. p. 200. ISBN 978-1-118-83375-9. Retrieved 2026-10-23.
- ↑ 8.0 8.1 Pickren, Wade E.; Rutherford, Alexandra (2010). A History of Modern Psychology in Context. Hoboken, New Jersey: John Wiley & Sons. p. 59. ISBN 978-0-470-27609-9. Retrieved 2026-10-23.