What principle suggests that a person experiences the world based on shifting focus?

The figure/ground principle is a key concept in psychology and perception that describes how individuals perceive objects (the figure) in relation to their surroundings (the ground). This principle illustrates that perception is not static; rather, it is dynamic and depends on what an individual is focusing on at any given moment. For instance, in visual perception, one might focus on a central figure (like a tree) while the background (such as a field) recedes. This shifting focus enables individuals to prioritize certain stimuli over others, which is essential in making sense of complex environments.

In the context of the choices provided, client-centered therapy primarily emphasizes the therapeutic relationship and the subjective experience of the client, rather than a principle of perceptual focus. Structuralism focuses on breaking down mental processes into their most basic components, largely ignoring the dynamic nature of perception. Behaviorism, on the other hand, concentrates on observable behaviors and external stimuli, without delving into the perceptual processes involved in an individual's experience of the world. Therefore, the figure/ground principle aptly encapsulates the idea of experiencing the world through shifting focus, making it the correct answer.