Sheldon Cooper is narcissistic, socially awkward, childish, hurtful, naive, irascible, selfish, rude, and irrepressible.
He is also extremely popular with viewers and even lovable. As "The Big Bang Theory" character has said, "This would be one of those circumstances that people unfamiliar with the law of large numbers would call a coincidence."
It is no coincidence that Sheldon has become one of TV's most popular characters, and has helped CBS' "Big Bang Theory" grow from a middling, predictable comedy to television's best multi-camera sitcom, and one that is still adding fans in its third season.
"The Big Bang Theory" is jokey and stupid yet smart and witty, and no character embodies all of that more than Sheldon.
As played by Jim Parsons, Sheldon is the ultimate sardonic outsider who's unaware and unconcerned of the implications of his observations, from which the show derives the bulk of the humor.
While his statements often stem directly from his vast intelligence, he's so smart and detached from normal human interaction that he's frequently a jerk.
Sheldon is brutally honest, often unaware of the implications of his observations, including his friends' hurt feelings. This isn't new for sitcom characters. Back in the 1980s, Sophia Petrillo was the Sheldon of NBC's "Golden Girls," largely because her stroke-induced inability to censor herself led to blunt observations about her roommates, including calling promiscuous Blanche a "human mattress."
Sheldon, though, doesn't rely on a stroke as an excuse for his observations. Instead, he deals with people as a scientist deals with experiments.
Asperger syndrome isn’t the answer
Jim Parsons, who received an Emmy nomination this year for playing Sheldon, says his character's approach to the world is influenced by the character's life as a child prodigy turned theoretical physicist, and that usually explains Sheldon's unusual, hysterical behavior.
Slideshow: Celebrity Sightings “In his mind, it has nothing to do with being rude or polite, it has to do with, ‘This is who we are, this is how we deal with it,’” Parsons said in an interview with msnbc.com.
There's been discussion about whether Sheldon is actually meant to have Asperger syndrome, a form of autism, but Parsons said that early in the series’ run, "I asked [the writers] point blank," and they said no.
More Entertainment stories
Autistic ballerina dances her way into hearts
In a popular YouTube video, the beaming little ballerina dances an entire four-minute routine seemingly perfectly, matchin...
- Every on-screen drink in 'Mad Men' in 5 minutes
- See the 'Dancing' stars' most memorable moves
- Emmy's biggest snubs? Cranston, Hamm, more
- 'Toy Story' toys burn up in prank on mom
- Autistic ballerina dances her way into hearts
Sheldon refuses to follow social norms and issues abrasive comments, but Parsons said his character is "not doing it to be mean." Sheldon "gets away with it because it's so based in fact.”
“You have to call out each fact as you would in the lab, as you would on paper,” Parsons said. “It's not impolite to name truths; they are what they are."
Sheldon names truths about his friend and roommate Leonard, and their friends Howard and Raj, but his most frequent foil is neighbor Penny, who lives across the hall and is now dating Leonard. Serving as a stand-in for viewers, she's the non-geek who may not understand Sheldon's references, but knows when she's being mocked.
"Nine times out of 10, I don't think there's a nefarious or bitchy edge to what he's saying. That's just how he calls it," Parsons said. "That's what keeps the edge from being too sharp a lot of times."
Even with Penny, Sheldon isn't entirely unemotional or unsympathetic. His recent face-off with nemesis Wil Wheaton proved that. A well-placed lie about Wheaton's “mee-maw” caused Sheldon to let Wheaton win a card game, only to later learn it was all a ploy. That scene showed that Sheldon “has a heart," Parsons said.
The show's writers take all of these juicy elements and run with them, and that's what makes Sheldon such a noteworthy character. He's complex in ways that most sitcom characters aren't, yet he has a clear shtick that works over and over again.
Like Sheldon, show doesn’t dumb down references
His combination of immaturity and exceptional intelligence makes for a lot of witty humor, even jokes that play off of otherwise tired material.
In “Big Bang’s” first season, Sheldon once retorted, "I'm polymerized tree sap and you're an inorganic adhesive, so whatever verbal projectile you launch in my direction is reflected off of me, returns to its original trajectory and adheres to you."
With Sheldon and other characters, "The Big Bang Theory" doesn't avoid complex vocabulary or references that might alienate some viewers; as a result, it's smarter than the average TV comedy while still frequently reveling in amusing stupidity.
It's also heavy with pop culture references that range from the geeky to the mainstream. All references, from the scientific to the cultural, are actually accurate, rather than gratuitous or embarrassingly inaccurate, like many shows that try to be relevant but end up exposing how clueless they really are.
Sheldon Cooper can deconstruct a person's behavior just like he'd dismantle an equation, and describe principles in theoretical physics with the same passion that he describes the intricacies of rock, paper, scissors, lizard, Spock.
The only real impossibility is not finding that to be utterly hysterical and completely human.
© 2013 msnbc.com. Reprints