<P> Sheldon Lee Cooper, Ph. D., Sc. D., is a fictional character in the CBS television series The Big Bang Theory and Young Sheldon, portrayed by actor Jim Parsons in The Big Bang Theory and Iain Armitage in Young Sheldon . For his portrayal, Parsons has won four Primetime Emmy Awards, a Golden Globe Award, a TCA Award, and two Critics' Choice Television Awards . The character's childhood is the focus of Young Sheldon; the series is set in 1989 when 9 - year - old prodigy Sheldon has skipped ahead five grades, to start high school alongside his older brother . </P> <P> Sheldon is a senior theoretical physicist at Caltech and did share an apartment with his colleague and best friend, Leonard Hofstadter (Johnny Galecki), until Sheldon moves across the hall with his fiancée Amy, in the former apartment of Leonard's wife Penny . He is a former child prodigy with genius level IQ, but displays an almost total lack of social skills, a tenuous understanding of humor, and difficulty recognizing irony and sarcasm in other people, although he himself often employs them . He exhibits highly idiosyncratic behavior and a general lack of humility or empathy . He also lacks toleration . These characteristics provide the majority of the humor involving him, which has caused him to be described as the show's breakout character . Despite speculation that Sheldon's personality traits may be consistent with Asperger syndrome, obsessive--compulsive personality disorder, and borderline asexuality, co-creator Bill Prady has repeatedly stated that Sheldon's character was neither conceived nor developed with regard to any of these traits . </P> <P> The character of Sheldon Cooper was inspired by a computer programmer personally known to series co-creator Bill Prady . He is named in honor of actor / producer Sheldon Leonard and Nobel Prize Laureate Leon Cooper . Chuck Lorre originally intended Johnny Galecki to play the role, but Galecki thought he would be "better suited" for the character of Leonard . Lorre said that when Jim Parsons auditioned for the role, he was "so startlingly good" that he was asked to reaudition "to make sure he hadn't gotten lucky". Sheldon is one of four characters to appear in every episode of the series, along with Leonard, Howard, and Raj . </P> <P> Sheldon was raised in Galveston, Texas along with his elder brother (George Jr .) and fraternal twin sister (Missy) by his mother, Mary Cooper, an overtly devout Evangelical Christian; and George Cooper, an alcoholic who was rarely around . Sheldon once got his father fired when he told Mr. Hinckley, the store owner, that George was stealing from the cash register . (Sheldon was rewarded with a fudgsicle .) In Young Sheldon, this is retconned: his father is a football coach who was fired from his coaching position in Galveston because he disclosed that other coaches were illegally recruiting players to their school, forcing the family to return to Medford . He does drink, but is a loving father who is trying to understand his intellectually gifted son . The only member of his family to have actively encouraged his work in science was his grandfather, whom he cherished and affectionately called "Pop - Pop", and who died when Sheldon was five years old . Pop - Pop's loss is what caused Sheldon to despise Christmas when his Christmas wish to bring Pop - Pop back didn't come true . Sheldon's closest relative is his maternal grandmother who he affectionately calls "Meemaw", and who in turn calls him "Moon Pie". His aunt also encouraged Sheldon by giving him medical equipment, "in case his work in physics failed, he'd have a' trade' to fall back on". </P>

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