Edward Thorndike was an early 20th century educator and psychologist who studied the learning process and influenced the development of the American public school system.

Professional Life

Edward Thorndike was born August 31, 1874 in Williamsburg, Massachusetts. He received his undergraduate degree from Wesleyan University and began his graduate work at Harvard. By age 23, he completed his PhD from Columbia University. 

Thorndike began his professional career at the Women’s College of Western Reserve University in Cleveland, Ohio, where he taught for one year, before accepting a teaching position at Teachers College at Columbia University in 1899. Thorndike remained at Teachers College until his retirement in 1940; his career focused largely on evaluating the learning process and testing intelligence. 

In 1912, Thorndike acted as president of the American Psychological Association. Thorndike also served as president of the Psychometric Society, after the first president and founder Louis Leon Thurstone, stepped down in 1937. Thorndike married Elizabeth Moulton in 1900 and they raised four children. 

Contribution to Psychology

Thorndike is known for his development of the law of effect, a theory regarding the effects of reward and punishment on learning. Thorndike originally believed that reward and punishment were equal in terms of effect, but he eventually determined that reward was far more effective and that punishment may actually lead to the repetition of an undesired behavior.

Similarly, Thorndike's connectionism states that behavior is a product of the connection of numerous neural and psychological processes. Behavior that cannot be explained by a simpler phenomenon, such as conditioning, follows connectionist principles. For Thorndike, learning is generally a gradual process built upon insight and increasing connections.

To study the learning process, Thorndike conducted a series of experiments involving animals and problem boxes and mazes. His subjects were rewarded when they were able to push a lever and escape, which they were able to do with increasing rapidity upon repetition. Thus, Thorndike concluded that the learning process was enhanced by the learner’s response to stimulus. B.F. Skinner built upon Thorndike’s law of effect in his behaviorist work with operant conditioning.

Thorndike identified three specific factors that benefit learning and result in maximum outcomes:

  1. The law of effect is determined by consequence.
  2. The law of recency requires that recurrence is determined by the most recent response.
  3. The law of exercise states that when a stimulus is administered upon response, each subsequent response is strengthened. 

Thorndike also developed military tests during World War I, when he was a member of the Committee on Classification of Personnel. His Alpha and Beta tests were used to measure the intelligence of soldiers. Thorndike’s tests were adapted for use among schoolchildren in the following years, and they directly impacted the development of standardized testing. Thorndike was a proponent of eugenics, because he believed that intelligence was a hereditary trait.


  1. Clifford, Geraldine Joncich. (2003). Edward L. Thorndike. Encyclopedia of Education. Retrieved from http://www.gale.cengage.com/InContext/bio.htm
  2. Tomlinson, S. (1997). Edward lee thorndike and john dewey on the science of education. Oxford Review of Education, 23(3), 365-383. Retrieved from http://search.proquest.com/docview/215839945?accountid=1229