Psychologists are often suspicious of attempts to group people according to types. Human beings, they argue, are simply too complex and too diverse. Many therapists share this dislike, arguing that once someone has a label they will live up to it – even when it is inaccurate. Nevertheless, people do seem to instinctively recognize such types. After all, how often have you heard someone say “I know his sort” or “I’ve met her sort before”?
A distinction must first be made between personality types and personality traits. Those who share a similar personality type will not have identical personality traits. Two people may differ in certain traits and yet still fit broadly into the same personality type.
Philosophers and physicians throughout history have tried grouping people in one way or another. Perhaps the best known of these systems is the four humors. According to this theory, which originated in Ancient Egypt, the human body contains four distinct fluids. When these are evenly balanced, you have good physical and mental health. When there is an excess or deficiency, however, the individual’s temperament will change.
The fluids were known as black bile, yellow bile, phlegm, and blood. If someone had too much black bile, they were liable to be ‘melancholic’, meaning morose, sullen and prone to depression; too much yellow bile and you have a choleric individual, meaning someone quick, irritable, and short-tempered; an excess of phlegm meant a phlegmatic individual, who was peaceful and relaxed; and, finally, too much blood produced a sanguine temperament, resulting in enthusiasm, sociability and energy. This classification system was still popular in Elizabethan England. Indeed, Shakespeare makes frequent references to the humors in his plays.
Introvert and Extrovert
One of the most interesting modern systems of classification was developed by the Swiss psychiatrist Carl Jung.
To begin with, Jung distinguishes the introvert from the extrovert. The extrovert is not necessarily loud and brash, merely someone who prefers to act first rather than plot and plan. If an extrovert spends too much time alone thinking, his energy levels drop. Put him with a group, however, doing something practical, and his energy levels will rise. The introvert is the opposite. He will prefer to analyze and plan before acting. And he is soon exhausted by company and activity. Unlike the extrovert, he needs time alone in order to recharge.
More generally, an extrovert’s psychic energy flows outward, towards people and objects. The introvert’s energy flows inward, and he is preoccupied with his inner life – with concepts and ideas rather than people. For the extrovert, action is all-important; for the introvert, thought is the priority. Of course, this does not mean extroverts are mindless, or that they do not value thought and knowledge. But they will seek breadth of knowledge; the introvert seeks depth.
Though introverts are inward focussed, they still seek social interaction. However, they seek deep, meaningful interaction, often with a small number of people. An extrovert will be more likely to value quantity over quality and frequency over depth. So, for example, an extrovert may be excited about the prospect of going to college because it will give him a chance to meet a wide variety of people from different parts of the country. The introvert will be more excited at the thought of making one or two close friends.
Jung’s Four Functions and the Psychological Types
Jung also had a theory of psychological functions. He divided these into the two perceiving functions (sensation and intuition) and the two judging functions (thinking and feeling).
The perceiving functions enable the individual to gather, interpret and understand new information. However, according to Jung some prefer to use their intuition and are thus more likely to trust information that is abstract or theoretical, information that can be woven into a larger pattern or theory and be related to the past or the future. They are also more likely to trust flashes of insight that seem to come from nowhere.
Those who favor the sensation function, on the other hand, prefer concrete facts. Such a person would be unlikely to attach much value to mystical or enlightened states, such as the satori of Zen Buddhism. For example, a policeman who was led by this function would be likely to dismiss his colleague’s ‘hunch’ and insist on detail and facts instead.
The two judging functions are then used to decide what to do with this information. If someone is guided more by their feeling function, they will try to feel their way into the situation and rely on empathy and imagination. Ultimately, they will seek to achieve harmony and consensus. The thinker will be more detached, using reason and logic and looking for consistency. He will also seek to match his decision with some set of rules or guiding principles.
Most people make use of all these functions, but, according to Jung, one of the four is generally dominant. When combined with the extrovert/introvert divide, you therefore have eight possible types: extroverted-sensation and introverted-sensation; extroverted-intuition and introverted-intuition; extroverted-thinking and introverted-thinking; and, finally, extroverted-feeling and introverted-feeling.
Of course, Jung is not the only psychologist to have developed a theory of types. The Harvard psychology professor Jerome Kagan, for example, divides people into two broad temperaments: inhibited and uninhibited. He bases this conclusion on extensive research into child development. Kagan noted the way certain children recoil from social interaction and display social inhibition even as babies. According to Kagan, such behavior remains generally consistent throughout adult life.
One of the most famous modern examples was developed by the mother and daughter Katherine Briggs and Isabel Myers. Using Jung’s ideas, they developed a questionnaire known as the Myers-Briggs test. This is then used to place the respondent into one of 16 different types. The Myers-Briggs test has become something of a fad on social media.
Ultimately, personality types are nothing more than broad sketches. Few people slot perfectly into one group, matching every trait required and lacking every other. Nevertheless, so long as they are not taken too literally, they can be very useful.