The Four Humors meme is based on the ancient Greco-Roman medical theory that human health and personality are governed by four distinct bodily fluids: blood (sanguine), yellow bile (choleric), black bile (melancholic), and phlegm (phlegmatic). In the modern internet era, this archaic concept has been revived as a character alignment tool, similar to the Dungeons & Dragons alignment chart or the Political Compass. Users typically take a cast of characters from TV shows, movies, or video games and assign them to one of the four temperaments based on their defining personality traits. This template serves as a versatile way to analyze group dynamics and explore humorous personality tropes through a historical lens.