Final answer:
Little Albert was a baby in a classical conditioning experiment by Watson and Rayner, where he learned to fear a white rat - an emotional response - which then generalized to other similar stimuli.
Step-by-step explanation:
Little Albert was the subject of a famous psychology experiment conducted by John B. Watson and Rosalie Rayner in the early 20th century. The study involved demonstrating how emotional responses could be conditioned using the principles of classical conditioning. In the experiment, a previously neutral stimulus (a white rat) became a conditioned stimulus (CS) when it was paired with an unconditioned stimulus (UCS) - a loud noise - to elicit an unconditioned response (UCR) of fear. After repeated pairings, Little Albert displayed a conditioned response (CR) of fear to the white rat alone. This fear also generalized to other similar stimuli, such as a rabbit, a furry coat, and a Santa Claus mask. However, Watson's methods would not meet modern ethical standards.