Classical conditioning is the process by which a naturally occurring stimulus is paired with a stimulus in the environment, and as a result, the environmental stimulus eventually elicits the same response as the natural stimulus. Classical conditioning is a type of learning where an unconditioned stimulus is paired with a neutral stimulus, leading to a conditioned response. Learn more. Classical conditioning (also known as Pavlovian or respondent conditioning) is learning through association and was discovered by Pavlov, a Russian physiologist. In simple terms, two stimuli are linked together to produce a new learned response in a person or animal. In classical conditioning, the initial period of learning is known as acquisition, when an organism learns to connect a neutral stimulus and an unconditioned stimulus.