Environmental psychology is a field that continues to grow very fast although it is difficult for scholars to confine it into the realm of scientific inquiry. The main reason why it is difficult to categorize this discipline as a science is that it measures subjective data such as reactions to light, heat, color and sound. This seems like impossible tasks for scientists to accomplish.
During the 1980s, Environmental psychology lacked a theoretical anchor around which research in this field could be tied. Preliminary research was being done in order to identify all the necessary variables that would be useful in the formation of a systematic framework. The main problem was defining different sets of measures to be used in investigations of different theories and basing every research on different everyday environments.
Russell and Mehrabian (1980) outline a framework through which environmental stimuli can be linked to various behavioral responses through such emotional responses as pleasure, arousal and dominance. This way, the impact the environment has on these responses can be assessed. Then, the effects this has on diverse stimuli components can be assessed. Russell and Mehrabian (1980) are also of the opinion that the ‘information rate’ concept can enable comparisons on the stimulatory effects of different environments to be made both within and across modalities such as heat, light, color and sound.
Bell et al (2005) describe the arousal perspective, a theory whereby increased arousal as a result of environmental stimuli is measured psychologically through the heightened autonomic activity. Such activities include blood pressure, increased heart rate, adrenalin secretion, respiration rate among many others. In this case, arousal is defined in neurophysiologic terms as increased brain activity in the reticular formation, which is the main arousal point in the human brain.
Another theory is environmental load perspective. In this approach, environmental psychologists study the way humans beings react to over-stimulation by environmental stimuli. Emphasis here is on information processing and principles of attention. This theory puts forth the claim that human beings have the ability to process only a limited number of all incoming stimuli. It also explains the concept of overloading, a situation whereby the incoming stimuli is too much for one to respond to. In this case, stimuli that are not very relevant are ignored and more attention is put on stimuli that are more important (Winter & Susan, 2003)
The environmental load perspective is very different from arousal perspective in terms of how adaptive responses are explained. Environmental load perspective explains adaptive responses within the backdrop of presence of disruptive stimuli. On the other hand, the arousal perspective focuses on the manner in which we respond to different stimuli. In the latter perspective, the issue of prioritizing on stimuli that are more important whenever there is overload is not discussed.
Both environmental load and arousal perspectives shed light on how human beings are psychologically affected by the immediate environments. Environmental psychology is therefore important for our understanding such core psychological concepts as attention, stimulus-response relationships and perception. Research in this field therefore forms a very important reference point for policy makers whenever impact of environmental problems on humankind is being assessed for purposes of legislation.