Short answers, pulled from the story.
Edward Thorndike is best known for the law of effect, which states that behaviors followed by satisfying outcomes are strengthened while those followed by annoying outcomes are weakened. He developed this principle through experiments with cats in puzzle boxes, and it became a foundational concept in behavioral psychology and educational theory.
Thorndike's puzzle boxes were wooden enclosures approximately 20 inches long, 15 inches wide, and 12 inches tall, fitted with a lever or button inside that opened a door when pressed. By recording how long cats took to escape across successive trials, Thorndike showed that animals learn through trial and error rather than insight, producing a gradual s-shaped learning curve.
Thorndike spent nearly his entire career at Teachers College, Columbia University, joining as an instructor in psychology in 1899 after completing his PhD at Columbia under James McKeen Cattell in 1898. He remained there for the rest of his career studying human learning, education, and mental testing.
Thorndike helped found educational psychology by combining learning theory, psychometrics, and applied research for school subjects. His law of effect directly shaped classroom use of praise and planned ignoring, and he published three word books between 1921 and 1944 to guide teachers in reading and vocabulary instruction.
In 2020, amid the George Floyd protests, the Board of Trustees of Teachers' College in New York voted unanimously to remove Thorndike's name from Thorndike Hall because of his racist, sexist, and antisemitic beliefs. Thorndike had been a proponent of eugenics and argued that women were by original nature submissive to men.
In 1929, Thorndike publicly acknowledged he had been wrong about parts of his framework. He denounced the law of exercise entirely after finding that practice alone did not strengthen an association. He also discarded the punishment half of the law of effect, concluding that punishment is not effective in modifying behavior while satisfying outcomes genuinely are.