3.2 Psychological types  (Page 13/13)

In this paragraph Jung describes what happens to the thinking introvert when his personality develops (his relations deteriorate and he becomes even more internal):

With the intensification of his type, his convictions become all the more rigid and unbending. Outside influences are shut off; as a person, too, he becomes more unsympathetic to his wider circle of acquaintances, and therefore more dependent on his intimates. His tone becomes personal and surly, and though his ideas may gain in profundity they can no longer be adequately expressed in the material at hand. To compensate for this, he falls back on emotionality and touchiness. The outside influences he has brusquely fended off attack him from within, from the unconscious, and in his efforts to defend himself he attacks things that to outsiders seem utterly unimportant. Because of the subjectivization of consciousness resulting form his lack of relationship to the object, what secretly concerns his own person now seems to him of extreme importance. He begins to confuse his subjective truth with his own personality. Although he will not try to press his convictions on anyone personally, he will burst out with vicious, personal retorts against every criticism, however just. Thus his isolation gradually increases. His originally fertilizing ideas become destructive, poisoned by the sediment of bitterness. His struggle against the influences emanating from the unconscious increases with his external isolation, until finally they begin to cripple him. He thinks his withdrawal into ever-increasing solitude will protect him from the unconscious influences, but as a rule it only plunges him deeper into the conflict that is destroying him from within.

Over time, the introverts ideas become more destructive and he becomes more isolated as a result - "His originally fertilizing ideas become destructive, poisoned by the sediment of bitterness. His struggle against the influences emanating from the unconscious increases with his external isolation, until finally they begin to cripple him. He thinks his withdrawal into ever-increasing solitude will protect him from the unconscious influences, but as a rule it only plunges him deeper into the conflict that is destroying him from within." His internal world of thinking destroys him from within because it becomes increasingly destructive.

A slightly different definition of extroversion and introversion was put forward by Eysenck (1964):

• The typical extravert is sociable, likes parties, has many friends, needs to have people to talk to, and does not like reading or studying by himself. He craves excitement, takes chances, often sticks his neck out, acts on the spur of the moment, and is generally an impulsive individual. He is fond of practical jokes, always has a ready answer, and generally likes change; he is carefree, easygoing, optimistic, and likes to "laugh and be merry". He prefers to keep moving and doing things, tends to be aggressive and lose his temper quickly; altogether his feelings are not kept under tight control, and he is not always a reliable person
• The typical introvert is quiet, retiring sort of person, introspective, fond of books rather than people; he is reserved and distant except to intimate friends. He tends to plan ahead, "looks before he leaps," and distrusts the impulse of the moment. He does not like excitement, takes matters of everyday life with proper seriousness, and likes a well-ordered mode of life. He keeps his feelings under close control, seldom behaves in an aggressive manner, and does not lose his temper easily. He is reliable, somewhat pessimistic and place great value on ethical standards.