The terms Extroversion, Ambiversion, and Introversion refer to the brain’s innate set-point of alertness and indicate the amount of stimulation in the environment that is optimum for a given brain. Think of your set-point as the typical, innate, stable level at which your brain and body function most energy-efficiently. Located in the first brain layer, Reticular Activating System (RAS) is believed to create this set-point, referred to by some as a person’s arousal or alertness level.
Some believe that a person’s position on the Extroversion-Ambiversion-Introversion (EAI) Continuum is more primary than even brain bent.
Hans Eysenck’s research led him to believe that the brains of human beings can be distributed along a metaphorical EAI Continuum based on their innate set-point:
- 15% to 16% are estimated to be very alert when fully awake (Introverts). These individuals tend to seek lower than average levels of stimulation in order to avoid being overwhelmed.
- 15% to 16% are estimated to be much less alert when fully awake (Extroverts). These individuals tend to seek higher than average levels of stimulation in order to feel alive and alert.
- 68% to 70% are estimated to fall in the middle of the continuum and are moderately alert when fully awake (Ambiverts). These individuals tend to function best with moderate or average levels of stimulation.
Some newer dictionaries list two spellings: Extroversion and Extraversion. Both terms refer to the same concept. Extroversion is the more common spelling and is the spelling used on this website.
My goal is to stimulate your thinking and observation, trigger increased awareness at an individual level, jumpstart your application of the information to everyday living, and provide options for behaviors that are more likely to result in positive outcomes. Although I have relied heavily on brain function research, a plethora of studies, and discussions with brain researchers and other experts, the summaries represent my own brain’s observations and opinions.
Typically, conclusions from research projects and studies are presented in the form of generalizations. They apply to about two-thirds of the population (e.g., the red portions on the drawing of the Bell Curve of distribution that represent the first standard deviation on either side of the mean). Because each human brain develops uniquely, however, there are always exceptions. Some of the remaining third of the population will tend to match the generalizations even more closely, and some less closely.
If some of your personal characteristics/behaviors don’t match a specific generalization in the Practical Applications section, it doesn’t invalidate the research. It does exemplify individual uniqueness, as no two brains are ever identical in structure, function, or perception, not even the brains of identical twins. Avoid discounting first-impression mismatches too quickly, however. Perhaps you haven’t had the opportunity to hone a specific skill, or your personal past experiences have impacted you in unusual ways.
Studies have identified several factors that combine to influence one’s position on the EAI Continuum. One of these factors is:
Approach to Experiences
Think of extroverts as tending to have a huge radar screen when accruing experiences. They usually prefer variety with different types of stimuli, and the more intense the experience the better. Life is about collecting experiences. They often have huge number of friends but may experience less intimacy in their relationships.
Introverts, who already have a high level of internal activity, tend to prefer less variety and to delve more deeply into each experience. Life is about pondering their experiences. Friendships sometimes follow this pattern, as well. Introverts may have fewer close friends, but experience more connection in their relationships.
An extreme extrovert and an extreme introvert may both like people equally well. Given the choice, however, each may gravitate toward different types of environments. Some may prefer to obtain their stimulation through association with other human beings; some prefer to engage in activities that don’t involve people (or that involve very few at any one time or for short periods of time only).
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Extroverts 16% *
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68%
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Introverts 16%
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| • Collect experiences and, typically, the more the better |
• Ponder experiences |
| • Generally prefer to jump in and participate rather than sit on the sidelines and observe |
• Prefer to observe rather than participate (at least initially) |
| • Act as a huge radar screen when accruing experiences; energy is drained in an environment with insufficient levels of stimulation (bored, restless, may fall asleep or even get into trouble) |
• Energy is drained in an over-stimulating environment (tired, depressed, sick) |
| • Prefer variety, high intensity, and differing types of stimuli (although may be less interested in depth for any one topic or situation) |
• Prefer less variety or intensity and more depth |
| • Score higher on “positive” current mood scales |
• Are more likely to dwell on negative features of social situations so tend to score lower on “positive” current mood scales |
*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.
PET scan studies by Dr. Debra Johnson have shown that brain blood-flow rates differ in extroverts versus introverts. Some of the behavioral differences between extreme extroverts and extreme introverts may result from using different brain pathways that influence where the individual directs his/her focus—internally or externally.
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Extraverts 16% *
- Lower rates of blood flow to the brain.
- Shorter, fast-acting, and less complicated blood flow patterns involve brain areas related to sensory processing (except for smell), variety, and novelty.
- Dominant pathway is activated by dopamine, a brain chemical that is implicated in most, if not all, addictive behaviors (e.g., adrenalin, amphetamines, and cocaine can increase dopamine levels).
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68%
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Introverts 16%
- Higher rates of blood flow to the brain (higher rates of internal stimulation).
- Longer, more complex blood flow patterns involve brain areas related to internal experiences (e.g., planning, pondering, remembering, recalling).
- Dominant pathway is activated by acetylcholine, a neuro-transmitter that affects one’s alertness and ability to pay attention.
|
*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.
Not long ago, a group of friends were discussing individual differences related to preference. One of the guests asked when dinner would be ready, and that led to the topic of food in general, which led to a discussion of the way in which different cooks or chefs might approach food preparation from the position of their innate giftedness. Soon a lively discussion was well under way. Here are some of their comments about extraversion, ambiversion, and introversion:
- Extroverts might want everybody crowded into the kitchen together, with lots of conversations going on at the same time, perhaps the TV on for the latest news or sports summary, and cell phones and pagers ringing periodically.
- Introverts would likely prefer cooking alone or with just one other individual present in the kitchen. They would likely have the TV turned off, and cell phones and pagers set to vibrate mode.
- Ambiverts might enjoy having a few people in the kitchen, but not too many, and perhaps not for the entire time!
A Brief Summary of Some Key Characteristics of the ends of the EAI Continuum
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Extroverts 16% *
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68%
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70% |
Introverts 16%
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| • Extroverts tend to be able to perform in situations that could overwhelm or that would be difficult (if not impossible) for more introverted brains. They are often able to perform better under pressure (e.g., exams, conflict, negotiations, performance). |
• Introverts may perform less well under pressure (e.g., exams, conflict, performance) or even shut down to some degree. |
| • Metaphorical calluses, as it were, protect the brain from being readily hurt or bested in highly stimulating, competitive, or combative situations. |
• The brain has no protective metaphorical callus. May try to shut out additional input in order to process the huge amount of data already inputted. |
| • Tend to be outer-directed. Constantly interact with the environment to obtain the stimulation the brain craves in order to feel alive/alert. |
• Tend to be inner-directed. Can retreat inward almost automatically to evaluate, ponder, and reflect on the data to gain new understanding. |
| • Tend to have an external focus and become energized by doing something in their outer world. Energy can be drained in an unstimulating environment. May have difficulty setting aside time to rest/reflect/relax. |
• Tend to have an internal focus and are energized by their internal world. Energy can be drained in large groups, noisy situations, or highly stimulating or competitive environments. It may take longer to recharge energy levels |
| • Tend to be less responsive to punishment. They are likely to continue acting in the face of frustration, and may take longer to form conditioned reflexes. |
• Tend to be more sensitive to punishment and negativity. They form conditioned reflexes more easily (e.g., are easier to train). |
| • Because of their constant search for stimulation and variety, extraverts are thought to be at higher risk for delinquency. |
• Because Introversion is not particularly rewarded in our society, they may be at higher risk for depression. |
Extraverts
Extroverts tend to hear sounds as softer than they really are (the action brain reduces the volume as sound data enter the brain) so they may be more likely to want to crank up the volume. They tend to want variety and can become quickly bored with routine and sameness as in practice and rehearsal. They may prefer performing with or touring with a musical group to obtain additional stimulation.
Being more outer-directed, extroverts may experience lower levels of anxiety prior to or during an actual performance. In addition, if the performance doesn’t meet their expectations they may look to the environment to identify contributing factors rather than focus on what they could do differently in the future.
Males who are extroverted may find it easier to concentrate in both practice and performance situations when the environment contains some distraction.
Females may find it more difficult to concentrate unless the practice and/or performance environment is very quiet.
Introverts
At the opposite end of the continuum, introverts tend to hear sounds louder than they really are (the action brain amplifies the volume as sound data enter the brain). Consequently, they are more likely to want to turn down the volume or wear earplugs to reduce the intensity of the sound.
Being more inner-directed, introverts may experience higher levels of anxiety prior to and/or during an actual performance, finding the event somewhat more stressful. They may overprocess their performance, pondering the musical nuances, applications, and outcomes. If the performance doesn’t meet their expectations they are more likely to blame themselves, assuming personal responsibility for everything whether or not that is the case. They may fail to look for a balance in identifying contributing factors outside their immediate control or that might be adjusted for in the future. This can lead to discouragement or even depression.
Ambiverts
Ambiverts tend to hear sounds at a relatively unaltered level (e.g., the brain neither significantly reduces nor amplifies sensory data as they enter the brain). They typically exhibit characteristics that are more balanced in contrast with the extremes.
*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.
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
| Extroverts
16% * |
 Ambiverts 
68% |
Introverts
16% |
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
Think 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.
Studies have identified at factors that combine to influence one’s position on the EAI Continuum. One of these factors is:
Style of Energy Recharging
Extroverts tend to have an external focus. Thus they tend to expend energy freely and refresh themselves by doing something in their outer world. These are the individuals who, at the end of the party, are still looking for another activity before they call it day. They may even have difficulty setting aside time to relax, to reflect, and to give their bodies a rest. Their energy can be drained in an understimulating environment, which is why they usually like to be where the action is. They can focus for short periods of time (e.g., library study) as long as there are frequent breaks, which can actually help them to concentrate.
Introverts tend to have an internal focus. Thus they are energized by their internal world. In general they need to pay attention to the amount of energy a specific activity will require because it can take longer for their energy to be restored, for their internal batteries to be recharged. While they are not necessarily quiet or withdrawn, they tend to refresh themselves by doing something reflective. They may have enjoyed the party but are likely to heave a sigh a relief and be glad it is over. Their energy can be drained in large groups of people, where there are high levels of noise, or where there are frequent interruptions or distractions. They can handle complexity unless it is required in too many arenas simultaneously. When overstimulated, the screen of the introvert’s mind may temporarily go dark (to use a computer metaphor) to allow for processing of what has already been absorbed.
Ambiverts, on the other hand, are believed to have moderate needs to some stimulation and relief from stimulation.
While you can override your innate position on the EAI Continuum, it can impact your energy levels (e.g., expend more energy, require additional time to recharge).
| Extroverts (16%) * |
68%
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Introverts (16%)
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| • Spend energy freely |
• Spend energy cautiously |
| • Energy is drained in an under-stimulating environment (bored, restless, delinquent) |
• Energy is drained in an over-stimulating environment (tired, depressed, sick) |
| • Recharge by interacting with outer world |
• Recharge by interacting with the internal world |
| • Need frequent breaks when trying to focus |
• Takes longer to restore energy |
* 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.
Your relative position on the EAI Continuum can impact not only your career path but also your situational comfort level while trying to complete key tasks. Brains with differing preferences can learn to complete the same types of tasks, but the relative energy expenditures may vary dramatically, as well as the success of the outcomes. Remember, ambiversion is somewhere between the two extremes.
Following are examples of key tasks correlated to the extremes of extraversion-introversion in combination with Brain Bent.
Key: E = Extraversion, I = Introversion.
Refer to the summary table that follows:
| Prioritizing Division
E = Negotiation, leading in times of plenty, situations involving goal setting and achievement (winning)
I = Research of almost any type, diagnosing, fiscal management, investigative writing and/or reporting |
Double *
E = Negotiation, trouble-shooting, SWAT team activities, some entrepreneurial ventures
I = Investigation, economics, scientific research, architectural design/drawing, investigative writing and/or reporting, some types of artistic endeavors |
Envisioning Division
E = New ventures, trouble-shooting, leading in times of crisis, self-directed work situations (e.g., truck driving, owner of a small business, consulting), entrepreneurial ventures
I = Computer programming, geology, philosophy, composing, self-directed work situations (e.g., consulting, resource specialist), artistic endeavors |
| Double *
E = Operational Management, Purchasing
I = Accounting, Engineering design |
|
Double *
E = Marketing, Public Relations,
Organizational Development, Consulting
I = Acting, Artistry, Decorating / Designing |
| Maintaining Division
E = Mechanics, assembling machines or equipment, assembly-line work, managing routines accurately, producing services for general public
I = Bookkeeping, stocking supplies, accounting, following detailed instructions sequentially |
Double *
E = Routine tasks and services (e.g., secretarial, teaching, nursing, concierge positions, receptionist positions)
I = Religious orders, bookkeeping |
Harmonizing Division
E = Teaching (elementary, high school), consumer affairs, public relations, chaplain or pastoral activities
I = Guidance counseling, counselor, interior decorating |
Some brains tend to use two cerebral divisions on a regular basis when processing information (although only one division typically represents their brain bent). Often these two divisions are adjacent to each other, but not always.
*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.
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Extroverts 16% *
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68%
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Introverts 16%
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| Tend to be less responsive to punishment, are likely to continue acting in the face of frustration, and may take longer to form conditioned reflexes. |
Tend to be more sensitive to punishment and negativity. They form conditioned reflexes more easily (e.g., may be easier to train). |
| May gravitate toward groups of people, or they may prefer to obtain their stimulation from activities that don’t involve people. |
May prefer one-to-one interactions with people or activities that don’t involve people. |
| Tend to be less sensitive to stimuli at all levels so can tolerate high-tension situations more easily. They can perform in situations that could overwhelm more introverted brains. |
Tend to be more sensitive to stimuli at all levels, including barely detectable levels of stimuli, so handle high-tension situations less easily. |
| Are often able to perform better under pressure (e.g., exams, conflict, negotiations). |
May perform less well under pressure (e.g., exams, conflict) or even shut down. |
| May use phone, fax, and e-mail as tools to help them compete successfully and “win,” but prefer being out where the action is. |
May be quite comfortable, or even prefer, communicating by phone, fax, or e-mail. |
| Can become bored quickly and may become restless or fall asleep if there isn’t enough stimulation available. Tend to be participators. |
Require relief from stimulation and may back off and/or need protection from too much stimulation. Tend to be observers. |
| Tend to excel at tasks that provide high levels of stimulation, interaction, and variety versus prolonged attention to detail. |
Tend to excel at tasks that require careful attention (e.g. reading radar screens, research labs with solitary cubicles). |
| Tend to fall asleep with low doses of sedatives. They may require lower doses of pain medication. |
Tend to require higher doses of sedatives and/or pain medication. May generate high amounts of anxiety when even anticipating the possibility of pain and/or discomfort. |
Tend to:
- Want to participate
- Be more outer directed
- Read to gain additional stimulation if nothing else is available
- Be seen as a party animal
- Debate and argue
- Compete (the BR will usually try to achieve a win/win)
- Roughhouse and fight
- Be labeled (by introverts) as noisy, restless, manic, undisciplined, and even ADD or ADHD
|
Tend to:
- Prefer to observe
- Be more inner directed
- Read
- Sit or stand alone
- Take a walk alone or a nap to decrease levels of stimulation
- Feel like “misfits”
- Be perceived by others as quiet, shy, nonparticipators, or even stuck-up
- Be labeled (by extraverts) as quiet, shy, loners, non-participators, wallflowers, scaredy-cats, or even stuck-up
|
| May be at higher risk for delinquency (as they search for stimulation and variety). |
May be at higher risk for depression. |
* 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.
Studies have identified factors that combine to influence one’s position on the EAI Continuum. One of those factors involves:
The thalamus, located above the brain stem, triages” incoming sensory stimuli and routes the data to decoding sites in the cortex. The Reticular Activating System (RAS) in the brain stem amplifies or reduces intensity of incoming sensory data—in some brains. The relative amount of amplification or reduction influences your innate position on the EAI Continuum.
The more the RAS reduces the intensity of incoming sensory stimuli, the more extroverted the brain tends to be and the more it craves significant levels of stimulation.
The more the RAS amplifies or magnifies the intensity of incoming sensory stimuli the more introverted the brain tends to be and the more it requires protection from stimulation.
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Extroverts 16%
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68%
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Introverts 16%
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| RAS reduces size and intensity (think “tabletop exercise” with miniature figures and objects) |
RAS magnifies size and intensity (think “bigger-than-life” with Jack-and-the-beanstalk figures and objects) |
| Can handle large amounts of data / stimulation – more resistant to punishment |
Can become overloaded quickly by too much input – more sensitive to punishment |
| Tend to need lower doses of pain and sleeping medications |
Tend to need higher doses of pain and sleeping medications |
* 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.
Studies have identified factors that combine to influence one’s position on the EAI Continuum. One of those factors involves the relative levels of norepinephrine.
As a neurotransmitter, norepinephrine (noradrenaline or noradrenalin) is concentrated in a group of neurons in the brain stem (action layer). This information substance influences our level of alertness, excitement, attention, dreaming, sleep, and mood. As a hormone, norepinephrine is synthesized by the adrenal medulla and is implicated in resisting stress. High levels of norepinephrine are associated with introversion, while lower levels are associated with extroversion. By extrapolation, moderate levels of may be associated with ambiversion. Levels of norepinephrine tend to increase during stress.
When the brain is subjected to chronic stress for two or more years, it may activate a state of protective alertness and the individual may be pushed temporarily toward introversion. Chronic anxiety can be caused by any number of situations (e.g., injury, severe or chronic illness, catastrophic disease or event, unresolved grief, trauma, crisis, prolonged or excessive adapting). With resolution of the chronic anxiety, the artificial level of protective alertness can decrease and the brain may be able to return to its innate position on the EAI Continuum.
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Extroverts 15-16%%
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70%
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Introverts 15-16%%
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| • Tend of have lower levels of norepinephrine |
• Higher levels innately |
| • Tend to do well at tasks that are high in excitement (e.g., SWAT teams, ambulance driver, negotiation in dangerous situations) |
• Tend to do better at tasks that require careful attention (e.g., radar-screen tracking, laboratory research, reading radiographic films) |
The present culture generally appears to reward amibevrted positions on the EAI Continuum. This means that more than half the population generally remains unrewarded by society in relation to their innate position on the EAI Continuum. Understanding this can help those who fall outside these two positions to recognize the artificial nature of societal rewards, and can give them the opportunity to identify, honor, and affirm themselves.
Many cultures deal rather ineffectively with both extremes on the EAI Continuum. Extraverted children are often punished and/or medicated in an effort to dampen their stimulation-seeking behaviors. Introverted children may be pushed toward competition and/or punished for a perceived lack of participation. In adulthood, extraverted males may get by easier than extraverted females (who may be perceived as too “out there” or not “nice” or not feminine enough).
On the other hand, introverted females may get by in society more easily than introverted males, perhaps because females are typically not encouraged to be as assertive or as aggressive as are males.
In Europe during the middle ages, introversion was generally valued over extroversion. Highly introverted individuals often entered one of the religious orders. It was considered a high honor to be removed from the bustle of materialism. In these protected environments introverts found solitude and found validation for their abilities to study, nurture others as caregivers, and write or compose. Some also found that the protected environment was conducive to developing a spiritual connection with a Higher Power.
As the shift toward industrialization occurred in society, ambiversion and extroversion came to be more highly valued, rewarded, and encouraged. At times ambiversion and some extroversion have been rewarded almost to the point of devaluing introversion. This is unfortunate because the entire EAI Continuum represents natural brain phenomena.
| Extroversion
16% *
Independent workers, star performers, deal makers |
Like to be in charge, the boss |
Ambiversion
Range
68%
Tend to gravitate toward teams |
Function best as expert resources |
Introversion
16%
Independent workers, often gravitate toward research |
* 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.
Most people are part of a some type of team during life. You may join a team by choice, because it’s the most efficient option for the task at hand, or because you’ve been assigned to one at home, work, school, church, or through a community organization.
While almost everyone can function in such a situation, individuals whose innate preference falls in the central position of the ambiversion range tend to gravitate toward involvement with a team. Those at the other positions generally do not. Individuals at other positions on the EAI Continuum can make valuable contributions in a team setting but they will likely expend much more energy in the process and may not perceive the experience as rewarding.
| Extraversion
16% *
Independent workers, star performers, deal makers |
Like to be in charge, the boss |
Ambiversion
Range
68%
Tend to gravitate toward teams |
Function best as expert resources |
Introversion
16%
Independent workers, often gravitate toward research |
* 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.
Think of each brain as having a metaphorical opening with an optimum diameter, although the aperture can dilate or constrict depending on the circumstances.
