Final answer:
Thorndike's principle that describes the strengthening of behaviors followed by positive outcomes and the weakening of behaviors followed by negative outcomes is called the Law of Effect.
Step-by-step explanation:
Thorndike's principle, that describes the strengthening of behaviors followed by positive outcomes and the weakening of behaviors followed by negative outcomes is called the Law of Effect or which states that behaviors followed by positive outcomes are strengthened and those followed by negative outcomes are weakened, is referred to as the Law of Effect. This principle was further developed into Operant Conditioning by B.F. Skinner. Skinner's work highlighted that the consequences of an action (reinforcement or punishment) served to either increase the likelihood of a behavior occurring again or decrease it. This phenomenon is well-illustrated by the Skinner box experiment, where animals learn to perform specific behaviors, such as pressing a lever, to receive a reward like food.