©Arlene R. Taylor PhD

The words Extroversion, Ambiversion, and Introversion refer to the type of brain a person possesses in terms of an internal or external focus, or a somewhat balanced combination of the two. Decades ago, C. G. Jung surmised that each individual could be placed on a metaphorical continuum somewhere between extremely extraverted and extremely introverted. His observations are being validated through PET Scan Studies. Research is also refining what is meant by differences. For example, in her book The Introvert Advantage, Dr Laney wrote that extraverts are not necessarily more outgoing than introverts.

Your innate relative position on a metaphorical EAI Continuum is vital to your sense of self. The brain tends to take in data more efficiently and process it more effectively when in a preferred environment. If you are not in an environment matches your specific needs for stimulation, you may be unable to engage in quality thinking. Comments in the book, Mapping the Mind, related to brain-scanning studies, appear to corroborate this. 

EAI Continuum

16% *

x Ambiverts x




Each human brain is believed to arrive on the scene with its own innate position on the metaphorical EAI Continuum already in place. Potentially, the extremes can be identified within days of birth. An infant with high needs for stimulation (extroverted) may sleep fewer hours, may stop crying only when passed around the room to a dozen caregivers, and rattle the crib or bang its head on the bed frame in an effort to find stimulation. An infant with low needs for stimulation (introverted) may sleep longer hours, stop crying only when placed in a quiet room or allowed to lie quietly instead of being rocked, and become ill when overstimulated.

Infants who don’t exhibit the extremes of extroversion or introversion fall within the ambiversion range. They have almost equal needs for stimulation and relief from stimulation. Ambiversion is identified by exclusion (e.g., if the infant does not exhibit characteristics of either extroversion or Introversion, there is a good possibility the infant is Ambiverted).

Compensating Behaviors

Individuals with introverted brains may become overstimulated if they try to keep up with the behaviors of those who are extroverted. In such situations, if introverts try to extrovert more than is natural for their brains, they may become fatigued, sick, or even depressed. The introverted brain may exhibit a variety of compensatory behaviors such as:

  • Withdraw from the group and run the risk of being labeled a loner, shy, too quiet, or stuck-up 
  • Engage in a solitary activity such as reading, walking alone, taking a nap
  • Be unable to focus or concentrate (e.g., overloaded with stimuli)
  • Exhibit immobility or isolation tendencies at least temporarily 

Individuals with extroverted brains may suffer from insufficient stimulation if they attempt to function in introverted environments. In such situations, extroverted brains may become quickly bored, restless, or even fall asleep. They may become dependent upon substances (e.g., caffeine, nicotine, amphetamines) to provide chemical stimulation to their brain to help them feel alive, alert, and engaged with life, or may be encouraged to take chemical stimulation in the form of medication (e.g., Ritalin). The extroverted brain may exhibit a variety of compensatory behaviors such as:

  • Become restless or anxious 
  • Be unable to concentrate and focus (e.g., attention may wander) 
  • Get into trouble with others or with the law (often unwittingly) in a search for stimulation) 
  • Engage in inappropriate or less than optimum behaviors in an attempt to obtain stimulation (e.g., bang head on furniture, make noises, constantly move around, tap fingers or pencil)

Two Sides of a Coin

xThink of extroversion and introversion as two sides of a coin. Each side appears to be quite similar in appearance for an ambivert, but rather different for an extrovert or introvert.

When engaged in activities that match your brain bent, you tend to exhibit behaviors that match your innate position on the EAI Continuum. When you are engaged in activities that are energy-intensive for your brain, the more likely you are to exhibit the opposite side of your EAI coin.

  *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.