There are many ways to make a group of people diverse without giving them overly specialized roles within an ensemble. One way is through matching personality types according to an ancient proto-psychological theory. The Four Temperaments (also called the "four humors") was a theory that behavior was caused by concentrations of body fluids — the "humors" of classical medicine: blood, yellow bile, black bile, and phlegm. A temporary imbalance would create an illness: too much blood caused a fever, too much yellow bile caused a cough, too much black bile caused depression, and too much phlegm caused a cold. A permanent imbalance led to a person having a certain type of intentions, behavior, and personality. Though this has been a theory long-since discredited from a scientific standpoint, the general idea still remains and the theory is still used for personality profiling. An ensemble based on these four humors can make the cast diverse without actually changing the roles of the characters in the story. One of the interesting factors in the Four Temperaments, is that there is no Leader - any one of them could be The Leader in the piece and defines the approach the team takes to the problem, while in a series the focus can switch back and forth to develop characters separately - see A Day in the Limelight. Rather than meeting through coincidence or brought together in the first episode, these four are more likely to be long-term friends or family from the start. There may be a fifth person hanging around occasionally but they're not really part of the team; they just add flavour or play the part of Mentor Archetype. Along with a list of characteristics, the four temperaments are: Sanguine (blood) Extroverted, cheerful, and people-oriented. In general, they are more empathetic, encouraging, confident, communicative, humorous, compassionate, sentimental and affectionate. Sometimes, they are explosive, impulsive and even unpredictable. Key Strengths: Charming, cheerful, loves people, energetic, talkative, passionate and compassionate, positive, expressive influencer, an excellent comedian, salesman or clown, quirky or eccentric, highly moralistic (mostly) and an outright fun person. In common with phlegmatic: Friendly, forgiving, optimistic endurer, emotionally available, will never get negative, good with relationships. In common with choleric: Adventurous, confident, hard to embarrass. Key Weaknesses: Undisciplined, too talkative, Euphoric-abatament, too energetic, scatterbrained, gullible, unpredictable, and disorganized. In common with phlegmatic: Weak-willed, likes to appease other people, gullible, too idealistic to the point of being unable to grasp what's gone wrong. In common with choleric: Impulsive, reckless, hot-tempered, thoughtless, and sometimes self-centered at times. Expressive high, responsive high; response's delay short, duration short. The Inspired Influencer of DISC and Myers–Briggs types generally: Artisans Will often correspond with the Optimist or the Apathetic when in a Four-Philosophy Ensemble. Amongst the five main "Dere Types" qualify as the extroverted and the cutie Deredere (Lovestruck) in best cases; The Pollyanna and Plucky Girl can also qualify. Oni type and Good Cop/Bad Cop: Brash Red Oni with snark, but an overall diplomatic "Good Cop". Corresponding element, season, and division of a day: (hot and moist) air, spring, and morning. In a person's life, it corresponds to young childhood (roughly ages 0-13). Organ: Liver/Lungs. The Yin-Yang Duo: Yang (white). The Four Gods: Azure Dragon. Planet or Satellite: Jupiter. Western Zodiac Signs: Gemini, Libra, Aquarius. Leadership type: Charismatic. Personality Blood Type: B Apocalypse Horseman: Conquest. Family member: Daughter. Cardinal Point: South. Piloting Style: Bushwacker. Typical Enneagram types: 2, 7. Emotion: Happiness/Joy. Stereotypical Hair Color: Blonde. Prominent English-speaking Country: Australia. Prominent Far-Eastern Country: Philippines, South Korea. State: Texas. City in the Philippines: Quezon City Basic Taste: Umami (or Spicy, despite not being one of the basic tastes) Archetypal color: Gold, brighter shades of yellow, all shades of pink or aqua (the colors of the Sky). Male/Female: Beta. Sense of Humor: Klutzy. Choleric (yellow bile) Extroverted, short-tempered, and task-oriented. Normally callous and unemotional, but will get angry for personal reasons. They tend to be magnanimous, enthusiastic, forward-thinking, tolerant, and strong-willed. Whoever has a choleric temperament will be a born leader, initiator, logical, of action, frank and who always takes the plans forward. Key Strengths: Takes the lead, hard worker, strong-willed, practical, passionate, a good repossession worker, security or military personnel, an excellent strongman/woman of the team (drill sergeant at the most extreme), determined, goal-oriented and sometimes thrives on criticism. In common with sanguine: Confident, loves a challenge, hard to embarrass. In common with melancholic: Good planner, independent, honest without any compromisation, Excellent agent of change, sheer hard worker. Key Weaknesses: Hot-tempered, rude, rebellious, can be cruel, stubborn, bossy, expects complete devotion, insensitive, often condescending, can become psychotic in overbearing situations, workaholic, without compassion or conscience, can be a warmonger, vengeful, a selfish cynic of a person's character, most likely a bad winner/loser, and may misinterpret jokes. In common with sanguine: Arrogant, boisterous, often dramatic, unhinged, unfiltered in speech, often likes to make "in your face" insults. In common with melancholic: Inflexible, emotionally distant, strict, demanding and fastidious, not very cooperative, vengeful, self-righteous and dogmatic, heavily sarcastic, tends sees the worst in people. Expressive high, responsive low; response's delay short, duration long. The Dominant Driver of DISC and Myers–Briggs types generally:Idealists Will often correspond with the Apathetic or the Cynic when in a Four-Philosophy Ensemble. Amongst the five main "Dere Types" qualify as Tsundere (Rude and Lovestruck), especially "Type A" and "Type B". Hot-Blooded can also qualify. May qualify as Yandere in more unstable cases. Oni type and Good Cop/Bad Cop: Red Oni and cruel, sheer "Bad Cop". Corresponding element, season, and division of a day: (hot and dry) fire, summer, and afternoon. In a person's life, it corresponds with adolescence and young adulthood (roughly ages 13-35). Organ: Gall bladder/Stomach. The Yin-Yang Duo: Yang (Red). The Four Gods: Vermilion Bird. Planet or Satellite: Mars and the Sun. Western Zodiac Signs: Aries, Leo, Sagittarius. Leadership type: Headstrong. Personality Blood Type: O. Apocalypse Horseman: War. Family member: Father. Cardinal Point: East. Piloting Style: Steamroller. Typical Enneagram types: 3, 8. Emotion: Anger/Rage Stereotypical Hair Color: Red/Ginger. Prominent English-speaking Country: United States. Prominent Far-Eastern Country: China, North Korea, Hong Kong. State: New York. City in the Philippines: San Juan. Basic Taste: Salty. Archetypal color: Darker shades of yellow, all shades of red or orange (the colors of a Volcano). Male/Female: Alpha. Sense of Humor: Brash. Melancholic (black bile) Introverted, brooding, and task-oriented. Normally highly sensitive and empathetic, but can be blunt. They are introspective, sensitive and very detailed people. They are usually those people who prefer to remain silent in their corner, reserved, suspicious, but very loyal and dedicated to the people they love. Key Strengths: Detailed, conservative, analytical, organized, perfectionistic, faithful to a fault, highly moralistic (mostly), discreet will of stone, elegant (in the more dignified ways), often selfless and an excellent medic, lawyer or scientist. In common with choleric: Excellent leader, practical, an effective organizer and punctual. In common with phlegmatic: Polite, ethical to a fault, deep, thoughtful, sensitive and gentle. Key Weaknesses: Rigid, too straight-laced, critical, pessimistic, moody, depressed, impractical (yes, both practical and impractical), has unrealistically high expectations, very paranoid. In common with choleric: Inflexible, can be snobbish, workaholic,emotionally distant, strict, resentful, vengeful, self-righteous and dogmatic, often sees the worst in people (and especially themselves). In common with phlegmatic: Shy, insecure, easily embarrassed, slowpoke. Expressive low, responsive low; response's delay long, duration long. The Contemplating Conscience of DISC and Myers–Briggs types generally: Guardians Will often correspond with the Cynic or the Realist when in a Four-Philosophy Ensemble. Amongst the five main "Dere Types" qualify as Kuudere (Mood-Swinger ) or a tendentially sad and depressed Dandere (shy and lovestruck). Sugar-and-Ice Personality can also qualify. Oni type and Good Cop/Bad Cop: Stoic, aloof Blue Oni, a cold "Bad Cop" with less affiliation (if not uninvolved). Corresponding element, season, and division of a day: (cool and dry) earth, autumn, and evening. In a person's life, it corresponds to middle-aged adulthood (roughly ages 35-65). Organ: Spleen The Yin-Yang Duo: Yin (black). The Four Gods: White Tiger. Planet or Satellite: Saturn and The Mercury. Western Zodiac Signs: Taurus, Virgo, Capricorn. Leadership type: Mastermind. Personality Blood Type: A. Apocalypse Horseman: Death. Family Member: Son. Cardinal Point: North. Piloting Style: Plugger. Typical Enneagram types: 1, 4, 6. Emotion: Sadness/Sorrow. Stereotypical Hair Color: Black. Prominent English-speaking Country: United Kingdom, Ireland. Prominent Far-Eastern Country: Taiwan, Mongolia. State: Illinois. City in the Philippines: Manila. Basic Taste: Both Bitter And Sour. Archetypal color: Navy blue, dark purple, olive or darker shades of green, all shades of brown or black (the colors of a cave or cavern). Male/Female: Sigma. Sense of Humor: Tragic. Phlegmatic (phlegm) Introverted, quiet, and people-oriented. Kind, sensitive, and empathetic towards others. They are a diplomatic person, who does not want to get into conflicts, who runs away from confusion. Sometimes impulsive, they are also more malleable than others. Doesn't like fights, is obedient, loyal, patient and fun. Usually assume passive postures in situations. They are homely, tolerant and very fond of being kind to people. note Key Strengths: Calm, humble, an excellent assistant, spy or librarian, discreet, flexible will of steel (flexible steel), elegant (in the simpler ways), thoughtful, patient, modest, a real sweetheart, accommodating, steady-paced, sympathetic, perceptive, normally has faith in morality (or indifferent to it), very compassionate, assuming innocent until proven guilty (or alternatively rational), a good listener, open-minded, considerate, and empathetic to all. In common with melancholic: Polite, reserved, gentle, ethical to a fault, dependable, can be popular among audiences, quiet and stealthy, a deep poker face, insightful. In common with sanguine: Pleasant, forgiving, witty, easygoing, idealistic endurer, emotionally available, a good sense of humour, good with relationships, accepting, playful. Key Weaknesses: Indifferent, submissive, lazy, slow, shy and passive, slacker, indecisive and too yielding, often neglected by others. In common with melancholic: Timid and docile, scared of sudden change, stubborn (about certain things), easily embarrassed. In common with sanguine: teasing, too compromising, forgetful, often unable to find what's wrong. Expressive low, responsive high; response's delay long, duration short. The Stable Supporter of DISC and Myers–Briggs types generally: Rationals Will often correspond with the Realist or the Optimist when in a Four-Philosophy Ensemble. Amongst the five main "Dere Types" qualify as Defrosting Ice Queen (Cool and Lovestruck) or a cutie and shy Dandere. May qualify as Yandere in more unstable cases. Oni type and Good Cop/Bad Cop: Blue Oni and gentle, diplomatic "Good Cop". Corresponding element, season, and division of a day: (cool and moist) water, winter, and deep night. In a person's life, it corresponds to older adulthood (roughly ages 65 and up). Organ: Brain The Yin-Yang Duo: Yin (blue). The Four Gods: Black Tortoise. Planet or Satellite: Venus and the Moon. Western Zodiac Signs: Cancer, Scorpio, Pisces. Leadership type: Levelheaded. Personality Blood Type: AB. Apocalypse Horseman: Famine. Family member: Mother. Cardinal Point: West. Piloting Style: Sniper. Typical Enneagram types: 5, 9. Emotion: Apathy/Indifference. Stereotypical Hair Color: Brown. Prominent English-speaking Country: Canada, New Zealand. Prominent Far-Eastern Country: Japan. State: California. City in the Philippines: Pasig Basic Taste: Sweet Archetypal color: Teal, green, white, gray, all shades of blue or black (the colors of the ocean). Male/Female: Gamma Sense of Humor: Dry The four temperament system, while interesting, was seen as flawed even back then as some people did not fit with any of the presented humors, so a neutral temperament has been used. Originally derived in modern temperament theory from the once popular FIRO-B psychometric instrument, which included moderate scales. When the temperaments were mapped to it, the traditional Phlegmatic ended up moderate in both "expressive" (classic "extrovert" and "introvert") and "responsive" (classic "people vs task" focus) scales, and the low expressive high responsive area was labeled "Supine". While it shares many common elements with the Phlegmatic, the difference is that the Phlegmatic is this way from a lower energy reserve which leads them to take the path of least resistance (to either go with the flow and be agreeable, or to be stubborn and slow), while the Supine has an emotional energy that drives them to be reserved, but wanting of acceptance from others. In alternative versions of the theory, the Phlegmatic kept in its old place, and the new temperament, here labeled as either "Leukine" (after leukocytes to match the body fluids theme) or "Eclectic", was considered the moderate one, sharing traits with all of the four temperaments (both "extrovert" and "introvert" and both "people-oriented" and "task-oriented"). In fiction this has been mostly reserved either for the lead character or more commonly for secondary characters (as for Four-Philosophy Ensemble, usually the Conflicted, but can also be Realist or Apathetic). Historically in plays, there was a whole genre: Comedy of Humors, where the impetus of the story is the sudden banding of these opposing types. This is in contrast to the Comedy of Errors, where the story is driven by the events and situations. They are similar to the four Personality Blood Types and are sometimes also a Classical Elements Ensemble. In the latter case, this typically overlaps with Elemental Personalities. See also Cast Calculus for the overarching archetypes in this and differently numbered ensembles. Here is an Image Archive for this trope. Additionally, Pseudolonewolf (of MARDEK fame) has a page that goes into great detail on the four temperaments, here (older version with blends here), Eric B has a page that explains the five temperaments here, and The Other Wiki offers its information here. For another way to split up a group of four, see Four-Philosophy Ensemble. If you want to write such a group, see Write a Four-Temperament Ensemble.