Final answer:
Kelly's perception of a flock of seagulls as one unit rather than individual birds is an example of the Gestalt principle of proximity, which states that objects close to each other are often seen as a group.
Step-by-step explanation:
The scenario where Kelly perceives a large flock of seagulls as one unit rather than as individual birds is best explained by the Gestalt principle of proximity. According to the principle of proximity, objects that are close to each other tend to be perceived as a group. This cognitive processing happens because our minds seek patterns and simplicity in the complex visual stimuli around us, thereby grouping the seagulls together based on their closeness in the sky, creating the perception of a singular, flowing unit.
Additional principles like similarity and closure also play a role in how we group sensory stimuli. The principle of similarity suggests that we group elements that are alike, and the principle of closure leads us to perceive incomplete figures as complete by filling in missing information. However, in the given scenario of seagulls flying at the beach, proximity is the key principle that applies.