Thorndike, Edward Lee (1874-1949), an American educational psychologist, made many contributions to the study of learning, teaching, and mental testing. He invented the puzzle-box to investigate how such animals as cats and dogs solve problems. He found that they tend to repeat only those movements that are successful. This leads them to a final quick solution. 

Thorndike also studied learning in human beings. He found that being right helped the student to retain a correct response, but that being wrong did not seem to eliminate errors. He conducted large-scale statistical studies to show how the study of Latin, mathematics, and other subjects affects the later school performance of students. He was one of the first to devise tests to measure learning and aptitudes. 

Thorndike was born in Williamsburg, Massachusetts, U.S.A. He received a Ph.D. from Columbia University, New York City, and taught at Teachers College, Columbia University, for 41 years. He developed a method to determine which words are used most often. His data was used as a basis for the Thorndike-Century and the Thorndike-Barnhart school dictionaries. His Teacher's Word Book (1944) lists 30,000 words by their frequency of use. His other works include Mental and Social Measurement (1904), The Measurement of Intelligence (1926), Fundamentals of Learning (1932), and The Psychology of Learning (1941).