Final answer:
Trial and error learning, as observed with cats in a puzzle box, was conducted by Edward Thorndike, who formulated the Law of Effect foundational for later behavioral theories.
Step-by-step explanation:
Trial and error learning is associated with the early work of psychologist Edward Thorndike. Thorndike's experiments involved placing hungry cats in a puzzle box to observe how they would learn to escape to get food.
This method of learning is characterized by an individual trying various actions until they find one that yields a positive outcome. Skinner, Pavlov, and Watson were all influential psychologists in the study of behavior, but it was Thorndike who conducted the puzzle box experiments and formulated the Law of Effect, laying the groundwork for the later development of operant conditioning by Skinner and classical conditioning by Pavlov.