Which example best illustrates stimulus generalization?

• A. A dog trained to sit responds to \"sit\" across different tones.
• B. A dog ignores cues in a new environment.
• C. A dog stops responding to a sound after repeated exposure.
• D. A dog starts to fear all wheeled objects after fear of a specific car.

Answer: (D)

Stimulus generalization happens when a response learned to one stimulus is elicited by similar stimuli. In this scenario, fear is conditioned to a specific car. After that learning, the dog begins to fear all wheeled objects because they share features with the car—movement, sound, or appearance that remind the dog of the original fear cue. That broad transfer from one fear-inducing stimulus to a whole category of related stimuli is the hallmark of generalization.

The other example shows the same idea of responding to variations of the same cue (the word “sit” spoken in different tones), which is still generalization but more narrowly tied to variations of the identical cue rather than a broader class of stimuli. The broader, more clearly generalized emotional reaction to all wheeled objects best illustrates stimulus generalization.