Edward L. Thorndike was an American psychologist known for his work in educational psychology and animal behavior. He is best recognized for his development of the Law of Effect, which states that behaviors followed by satisfying outcomes are more likely to be repeated, while those followed by unpleasant outcomes are less likely to occur. This principle laid the groundwork for later theories in behaviorism. Thorndike's experiments with cats in puzzle boxes demonstrated his theories on learning and problem-solving. His research contributed significantly to the field of psychology, influencing both educational practices and the understanding of learning processes in animals and humans alike.