Answer:
Generalization gradient
Step-by-step explanation:
In psychology, a generalization gradient refers to the tendency to generalize a behavior when similar stimuli are presented, in other words it refers to the tendency that a behavior is more likely to occur in presence of stimuli that are more similar to the discriminative stimulus (the one that generates the behavior) than in presence of stimulus that are very dissimilar to the discriminative stimulus.
Therefore, this is called a generalization gradient.