Answer:
The answer to the question: What type of design was used by Watson and Rayner (1920), would be: Controlled experiment on one individual with no control subjects.
Explanation:
The "Little Albert" experiment, which was conducted by John B. Watson and Rosalie Rayner, and which was published in 1920 in the <em>Journal of Experimental Psychology </em>became famous because of its use of the Pavlovian theory of classical conditioning, to show how phobias could develop in humans, given the correct stimulation, and in direct response, without intervention from any abilities, or extras. There was just stimulus, and learned response. In Little Albert, an infant, and the only subject of the Controlled Study, was exposed first to some animals and objects with certain characteristics, and later exposed to a sound that scared him. In time, he learned to associate the stimuli (animals with the sound that scared him) and his response was to cry when the animals, or objects with similarities, appeared before him. Thus, a phobia was developed. It was a controlled experiment because all variables were under the control of the researchers, including the number of subjects, the type of stimulus that would be used. Nothing was random, all was selected by the researchers, with the only intention of seeing how the fear towards something developed in direct line with a harmful stimulus and a neutral stimulus.
