1. the theory that the physical environment can affect arousal levels by stimulating brain-based mechanisms. Stress and arousal are created when psychological or physical needs are not met. Arousal, and therefore stress, increases when personal space is diminished (see crowding) or when people are subjected to noise or traffic congestion. See also activation theory of emotion.
AROUSAL THEORY: "Arousal theory posits that the physical environment can bear influence on arousal levels, and that crowded environments, for example, traffic congestion, increase arousal in the body."