The answer is proximity in which the perceptual tendencies t group together stimuli that are close each other. The rule of proximity denotes that humans distinguish stimuli that are near to each other by grouping them and distinguishing them as a portion of the identical object. In the meantime, stimuli that stand far from one another are parts of two or more dissimilar objects. The space that describes how close or far the stimuli are from each other is subjective to every individual.
