©Arlene R. Taylor PhD

Studies have identified at several factors that combine to influence one’s position on the EAI Continuum. One of those factors involves the size of the metaphorical aperture.

openingThink of each brain as having a metaphorical opening with an optimum diameter, although the aperture can dilate or constrict depending on the circumstances. 

Metaphorical Opening

The extroverted brain has a small aperture that takes in less data second for second but can focus narrowly. Consequently it is continually searching for the stimulation it requires. If it doesn’t receive sufficient stimulation it can become quickly bored and even fall asleep.

The ambiverted brain is believed to have a medium-sized aperture that takes in moderate amounts of data second for second. It typically spends about half its time seeking stimulation and half its time seeking relief from stimulation.

The introverted brain has a large aperture that takes in huge amounts of data second for second. This brain can become overloaded quite quickly and needs protection from overstimulation; otherwise, the individual can become ill.

x Extroverts 16% *



Introverts 16%x

Can zoom in (as it were) and focus on the situationTake in large amounts of data second for second
Better short-term memoryBetter long-term memory but recall may fail under stress
Tend to tolerate high-tension situations better (e.g., exams)Tend to be more sensitive to stimuli at all levels
 Less easily distracted by surroundings when interested in the goal or taskMore easily distracted by surroundings even when interested in the goal or task


Eysenck Personality Questionnaire. Extraverts/extroverts, according to Eysenck's theory, are chronically under-aroused and bored and are therefore in need of external stimulation to bring them up to an optimal level of performance. About 16 percent of the population tend to fall in this range. Introverts, on the other hand, (also about 16 percent of the population) are chronically over-aroused and jittery and are therefore in need of peace and quiet to bring them up to an optimal level of performance. Most people (about 68 percent of the population) fall in the midrange of the continuum, an area referred to as ambiversion. (http://en.wikipedia.org/wiki/Eysenck_Personality_Questionnaire) Accessed 12/13.