stimulusgeneral

Stimulus generalization is a psychological phenomenon in which a learned response to a specific conditioned stimulus elicits similar responses to stimuli that resemble it. In classical conditioning, if a dog learns to salivate to a particular tone (the conditioned stimulus, or CS), it will also show salivation to tones that are similar but not identical. The strength of the response typically decreases as stimuli become less similar, producing a generalization gradient.

The concept helps explain how organisms respond to new but related cues. Generalization arises from the brain’s use of similarity-based representations, and can be influenced by the degree of similarity, salience, and prior experience. Discrimination training, where nonreinforced similar stimuli are contrasted with reinforced cues (CS+), can shift or narrow the gradient, a phenomenon related to the peak shift.

Factors that affect generalization include sensory modality, stimulus complexity, motivational state, context, and reinforcement history. Generalization can be adaptive, enabling rapid responses to related situations, or maladaptive, contributing to the spread of fear or maladaptive habits.

Applications include behavior therapy for anxiety disorders, where excessive generalization of fear to related cues is targeted through exposure and extinction; in animal training to promote flexible responding; and in marketing to understand how products or cues elicit broad but related responses.