Sheldon Cooper

Sheldon is a theoretical physicist from Caltech who rooms with Leonard in their rundown apartment building, in which the elevator always seems to be out of order. He is Leonard's best friend and colleague, who appears to have OCD, beginning with suspicion of it in episode 1x02. Like Leonard, he keeps a whiteboard in the living room for scientific theories, especially for his work on string theory. Unlike Leonard, he embraces his genius fully and doesn't mind sharing details of his life that Leonard finds embarrassing, such as their main weekend activity being Klingon Boggle tournaments until 1 AM. It's indicated that Sheldon's genius is concentrated fully on science and that his IQ is higher than Leonard's; he tends to question Leonard's theories and has a larger background full of behavior common to child prodigies. When he was a child, he conducted experiments involving the height of stairs and deduced that if a step on a staircase is 2 millimeters off or more, a person is always likely to trip (this resulted in his father breaking his clavicle). At age 14, he dabbled in lasers and this resulted in his being sent to boarding school; it is heavily implied in a CBS promotional clip that the government took Sheldon's laser away and hushed the college professor who witnessed the experiment. According to his mother, Sheldon also attempted to build a nuclear reactor at a young age in order to provide free electricity for his town; that failed after a government agent informed him that it was illegal to store yellowcake uranium in a shed. Sheldon graduated high school very early; he asks Penny, in complete disbelief, "It took you four years to get through high school?!" He told Penny he was eleven years old when he was going to college. Sheldon also has common qualities associated with being a prodigy, such as an inflated ego, social ineptness, and an inability to identify emotionally with others. He fails to understand not only the simplest sarcastic jokes made by Leonard, but also regards Penny's sadness over her break up with blatant disgust. That isn't to say Sheldon doesn't have a conscience; he's simply more likely to do what's scientifically ethical (not donate to a "high IQ sperm bank" because his sperm won't guarantee high IQ offspring) rather than morally and socially ethical (break into Penny's home to organize her things). Sheldon also remains unswayed by Penny's beauty. He also has symptoms of obsessive compulsive disorder and Asperger Syndrome; when he finds Penny's apartment messy, he sneaks in during the night and cleans it up because he can't stand being in the same hallway with something so disastrous. Also, he refuses to sit anywhere other than his designated spot on the couch. He is calculating and cynical, believing that Leonard is only setting himself up for disappointment as he continues to crush on Penny.
 * Sheldon has an IQ of 187.
 * Sheldon suffers from Asperger syndrome, which makes him unable to understand sarcasm, and relate to other people's feelings.
 * Sheldon has switched his reasearch from bosonic string theory to heterotic string theory.
 * Sheldon has two siblings, one of whom is a (fraternal) twin sister who hostesses at Fuddrucker's.
 * Sheldon loves to eat at Big Boy, an American restaurant chain.
 * Sheldon conducts research at the University, primarily in string theory.
 * Sheldon has 212 friends on Myspace.
 * Sheldon wears briefs.
 * Sheldon is allergic to bees and cats, and also has asthma.
 * Sheldon cannot detect sarcasm.
 * Sheldon loves Battlestar Galactica, Doctor Who, and Star Trek.
 * Sheldon has a Master's degree and two PhDs.
 * Sheldon entered graduate studies at fourteen years old, and received his first PhD at sixteen years old.
 * Sheldon was a visiting professor in Germany at fifteen years old.
 * Sheldon took four years to write his thesis.
 * Sheldon sometimes wears vintage t-shirts adorned with superhero logos, among them the Flash, Superman, Aquaman, and the Green Lantern.
 * Leonard and Sheldon own Dell XPS laptop computers.
 * Sheldon and all of his friends play World of Warcraft, as seen in episode "The Fuzzy Boots Corollary." Sheldon is a knight elf rogue.
 * Sheldon and all his friends play Halo 3 every Wednesday.
 * Sheldon doesn't believe in luck or coincidence, instead citing the Law of Large Numbers (LLN) in Statistics as the explanation for such phenomena.
 * Sheldon was sick a lot as a child.
 * He can play the keyboard and presumably the piano.
 * Sheldon keeps his toothbrush in a plexiglass case under a UV lamp.
 * Sheldon labels all home utensils, appliances, etc.
 * Sheldon showers twice a day and washes his hands as often as he can.
 * Sheldon has to sit on the left side of the couch. Wherever he goes, he has to choose the best sitting location based on such things as optimal television viewing, lighting, and cushion density.
 * Sheldon was born in a K-Mart.
 * Sheldon was raised in an aluminum trailer in east Texas.
 * Human relationships continue to baffle and repulse Sheldon.
 * Sheldon likes drinking diet coke.