Around 400 BCE, the Greek philosopher and doctor Hippocrates laid out a system of classifying people based on the balance of certain fluids in a person's body. According to him, an individual's personality could be one of four: Sanguine (too much blood), Choleric (too much yellow bile), Melancholy (too much black bile1), or Phlegmatic (too much phlegm). In many ways, this corresponds to the Myers-Briggs personality type indicators: Sanguines are generally ExFx, Cholerics are ExTx, Melancholies are IxTx, and Phlegmatics are IxFx:

                 Thinkers      Feelers
  Extroverted |  Choleric  |  Sanguine  |
  Introverted | Melancholy | Phlegmatic |

Although the medical basis for this theory has been discredited for hundreds of years (accepted as truth by the Catholic Church until the 18th century), it still remains a functional model of basic personality types: the popular, the powerful, the perfectionists, and the peaceful. Most people are some combination of two or more types, but one almost always dominates the others. Ben Johnson even went so far to write two plays2 about the concept.

Sanguines are the good-humored life of a party. They're cheerful and enjoy being the center of attention. When they take on a task, they inspire or charm others to join in even if they don't always see the task to completion. They're generally good at speaking in public and thrive on compliments. They sincerely care for other people and are deeply troubled if they think they've hurt anyone else. On the downside, they're generally loud and self-centered, which can sometimes drive more introverted people away.

Cholerics don't just think they're right, they usually are right. They're the CEOs, the politicians, and the crazy High School fine arts teachers. As born leaders, they dynamically seek to fix all that is wrong in the world, constantly pressing on to their goals. They're very routine and organized, not hesitating to examine the big picture and form a practical solution. They usually come across as inflexible and unsympathetic due to their lack of tolerance for trivia or dissenting opinions.

Melancholies are deep, analytical, and quiet. They're generally the engineers, artists, authors, and programmers. They're very serious and prone to genius-level intelligence, which makes them excel in music, art, and philosophy. They're always ready to make personal sacrifices to meet goals, finding creative solutions to a wide array of problems. They're neat and orderly, thriving on trivia and detail. This often gets them labelled a perfectionist, driving away some of the more extroverted types. They're incredibly compassionate and empathetic, but make friends carefully. What friends they do make, however, they're hopelessly dedicated to.

Phlegmatics are best described as calm, cool, and collected. Because of their level-headedness, they're born mediators, generally preferring to listen and form a complete opinion before sharing their thoughts. They're peaceful and agreeable, with many friends. This gives them a natural ability for administrative tasks. They tend to find the easy way out and avoid conflicts, which will come across as lazy at times, but their concern and compassion make up for their unenthusiasm.

Personality Types of Noders

I've taken care to write a small perl script that measures the balances of a person's personality type. It's located at The questions all came from photocopies of a book3 my stepfather had on personality type theory. If you take it, please /msg me so I can add you to the list.

Sanguine (popular): Byzantine, Chihuahua Grub, ClockworkGrue, (darsi), dwardu, DreamVirus, edebroux, factgirl, Footprints, graceness, heyoka, JayBonci, Jethro Bodine, mr100percent, resc, qousqous, siouxsie, Tem42, toastido, and Void Ptr.

Choleric (powerful): akwardsaw, Ashigaru, beldin, Emphyrio, Eraser_, Great Neb, hashbrownie, ism, Jennifer, karmaflux, mauler, oenone, SEF, slobertje, Spilf, Starke7764, Teiresias, vladkornea, and WonkoDSane.

Melancholy (perfectionist): amnesiac, Anark, asofel, Bitriot, cahla, Carthag, cid highwind, Cletus the Foetus, codepie, dann, DataJunkie, enth, fnordian, Halspal, iandunn, icicle, Infinite Burn, jaubertmoniker, jeeves, JerboaKolinowski, kenata, liveforever, Lometa, MacArthur Parker, mofoaha, nihilanth, ophie, Professor Pi, pyrogenic, RainDropUp, ReiToei, Ryan Dallion, sakke, sauth, SophiesCat, StopTheViolins, Tandex, The Alchemist, TheChronicler, TotalRetard, Toxick, uncleozzy, wuukiee, XCthulhu, xdjio, xriso, and zophos.

Phlegmatic (peaceful): 1010011010, atesh, Bill Dauterive, Billy, bis, BlueDragon, Blush Response, ccunning, cletus the foetus, cow of doom, dinkybug, discofever, dizzy, DyRE, Invis, Hermetic, Fitch, getha, getzburg, knifegirl, legbagede, mer, narzos, novasoy, orion, Phyllis Stein, PsionicMan, pyramidhead, rio, Segnbora-t, sparkley, taschenrechner, wertperch, Wolfdaddy, and VirtualWolf

1 - Hippocrates spoke of 'black bile', but what that corresponds to in modern medicine has yet to be determined.
2 - Every Man In His Humor and Every Man Out Of His Humour.
3 - The book is old enough to be out of copyright. I'll place the ISBN here if I ever find a copy.