Captain's log #3392 - On Extroverts and Introverts

I came across this in an ezine today and thought it interesting. You kind of have to read what the professor has to say before you read the conclusions at the bottom, sorry about that.

Dr. David Meyers, Professor of Psychology at Hope College:.

Inside the brain stem, extending from the spinal cord right up into the thalamus, is a finger-sized network of neurons called the reticular activating system (also called the reticular formation). Most of the spinal cord axons of sensory neurons travel up to the thalamus. Along the way, some of them branch off to the adjacent reticular system.

Thus, when sensory stimulation occurs, the reticular system is activated. The reticular system transmits information about its state to the cerebral cortex, which in turn arouses the brain. Under the influence of the cortex, the reticular system controls not only arousal but attention.

Some individuals are more sensitive to environmental stimuli and therefore shy away from becoming overly involved in the environment (Introverts), while others are less sensitive and tend to seek out environmental stimuli to maintain active levels of interest (Extroverts). All individuals try to shift their behaviors to the environment in such a way as to increase their level of comfort and to decrease their level of discomfort. 

The reticular activating system also affects individual attention levels. Introverts, being overly sensitive to the environment, pay more attention to weaker stimuli (less intense), often withdrawing from stronger stimuli (more intense), which tend to overpower them. That could be why introverts sometimes tend to magnify, distort, and “overreact” to experiences that are intense and/or stressful.

In contrast, extroverts—less sensitive to what is occurring around them—tend to become disinterested with weaker stimuli; they pay closer attention to, and are more motivated by, intensity.

Extroverts sometimes have a tendency to “underreact” to situations where there is not enough stress or stimulation. Thus, extroverts and introverts often prefer different activities, physical surroundings, and even friends or associates, due to their personal level of sensitivity and response to environmental stimuli.