The Physiology of Jung's 4 Psychological Functions

  • Extraversion

    Having a naturally low level of arousal which causes the individual to seek higher than normal levels of stimulation in order to "feel alive."

    Typical ways in which the extravert seeks stimulation include: trying to influence or control his or her environment; confronting others; engaging in competition; attending crowded parties or events "where the action is".

  • Introversion

    Having a naturally high level of arousal which causes the individual to seek lower than normal levels of stimulation in order to not feel overwhelmed.

    Over a period of years, this need to not be overwhelmed by external stimulation develops into an internally focused thinking style which may seem withdrawn, meditative, quiet, or even reclusive to more extraverted persons. Typical ways in which the introvert seeks to control the level of stimulation include: spending time reading, reflecting, or otherwise alone; avoiding or being accommodating to others; competing mostly with oneself or self image; going to small parties or out of the way places.

Additionally, it is important and helpful to understand the:

  • Physiology of Chronic Anxiety

    When we are subjected to some type of chronic anxiety for months or years, it is our R.A.S. which shifts its set point so that we are continually more alert in our general waking state. Subsequently, we naturally become more introverted until we address the source of our chronic anxiety. Although somewhat disorienting, this shift is fully reasonable as it causes us to be more introspective, thereby increasing the chances that we will notice that we are living under some types of chronic anxiety which is "frightening" us and causing us to live on edge, always a bit in fear. As such anxiety is usually the result of some life choice we have made or some way we are living our lives, the increased level of introspection increases the probability that we will see the problem at the level of the problem and solve it. When this is done and the source of our anxiety is resolved, we can quite naturally return to our normal level of wakefulness.

Subsequently, by juxtaposing what we have learned physiologically, with Jung's own observations on extraversion and introversion, we have a clearer appreciation for Jung and as well as tools such as the MBTI and BTSA, others are using to help people apply Jung's model to empower and guide themselves. Here for example are five questions, which have left many people confused about Jung, Type or the MBTI for several years. In the light of the new information science provides, the confusion surrounding each question dissolves.

  1. Jung saw Introversion as "saying no to life" and at the same time, a natural, normal way of being?

    According to Dr. Hans Eysenck, Jung was 100% correct when he said that Introversion is a normal and healthy way in which many people live life, based on their physiology. At the same time, Jung was also 100% correct when he noticed that at least some Introverts seem to be saying no to life.

    In point of fact, Introverts actually take in so much information second per second that they might be said to be "gulping in information" - a definite yes to life. Yet, the fact that overly loud environments in which a lot is happening can cause them to be "overwhelmed" can cause them to appear to be saying — in that highly stimulating context — no to life, when in fact what they are saying no to is simply the experience of being overwhelmed.

    As well, some Introverts develop a negative attitude towards life as a result of being continually shamed or devalued when they live in a culture which seems to value and reward Extraversion more than Introversion. This is certainly the finding of Elaine Aron in The Highly Sensitive Person: How to Thrive When the World Overwhelms You.

    Yet another factor which "gives Introverts a bad name" is this one. Many people, under chronic anxiety — brought about by many consecutive years of high stress — develop a negative attitude because of the stress they have had to face. At the same time, these people experience a shift as a result of the chronic anxiety, in their arousal system. They become more Introverted. Indeed some natural Extraverts become so "stressed out" their arousal shift so much they actually appear to be Introverts. All these people — who are experiencing a higher level of Introversion as a result of chronic anxiety — reinforce the older belief that "Introverts say no to life."

  2. Why are Extraverts sometimes mistakenly identified as Feeling Types?

    Many Extraverted people have been thought to be Feelers when they were actually natural Sensors, Thinkers or Intuitives. The reason is that all Extraverts are attracted to people because people are a dependable source of stimulation — from conversations to playing games to fighting or arguing. Quite often, in a business meeting, someone will identify another person as "a real people person". This person may be a Feeler, but he or she is just as likely to be a Sensor, Thinker or Intuitive.

  3. Why do those working with the MBTI sometimes have difficulty determining whether a person is actually Extraverted or Introverted?

    The answer here is two fold. On the one hand some people according to Eysenck actually have a Balanced level of arousal such that they are neither highly Extraverted or Introverted. On the other hand, people do shift in response to chronic anxiety. Some people who are naturally Extraverted may appear markedly less so as a result.

  4. Why some persons profiled with the MBTI two or more times several years apart report being told they were Introverted on one occasion and Extraverted on another occasion — or visa versa.

    As noted above, a natural Extravert may measure as Introverted when he or she has been living for some years in a state of heightened anxiety. Prior to this period of stress and anxiety, the person may well measure as an Extravert. Subsequent to the onset of this period of stress / anxiety, the person may well measure Introverted. And yet, again, when the source of stress and anxiety has been resolved, the person might be tested again and be found to be once more Extraverted.