Stimulus generalization occurs when

• A. A conditioned response is elicited by stimuli similar to the conditioned stimulus
• B. A response is extinguished when the CS is removed
• C. A new behavior is learned via reinforcement
• D. A stimulus is never similar to the CS

Answer: (A)

Stimulus generalization is the tendency for a conditioned response to be triggered by stimuli that resemble the original conditioned stimulus. After learning that a particular cue predicts something important, the subject may respond not only to that exact cue but also to similar cues because they share features with the original stimulus. This happens because those similar cues set up a comparable expectation or association, producing the same learned response.

This is why a description where a conditioned response is elicited by stimuli similar to the conditioned stimulus best captures the idea. Extinction, by contrast, is the process of the response declining when the conditioned stimulus is presented without the unconditioned stimulus, which isn’t about responding to similar cues. Reinforcement of a new behavior pertains to operant conditioning, not classical conditioning. And a stimulus that is never similar to the conditioned stimulus wouldn’t trigger generalization at all.