Characters / The Big Bang Theory: Sheldon Cooper

The Big Bang Theory Main Character Index
The Core Group (Sheldon Cooper, Penny) | Family Members | Secondary Characters | Minor Characters

Young Sheldon Main Character Index
The Cooper Family (Sheldon Cooper) | Other Characters

---

Dr. Sheldon Lee Cooper, from The Big Bang Theory and Young Sheldon

^{Click here to see him in Young Sheldon}

Played by: Jim Parsons (The Big Bang Theory and Young Sheldon as the narrating older Sheldon), Iain Armitage (Young Sheldon as the younger version of Sheldon)

Voiced by: Luis Alfonso Mendoza (Latin-American Spanish dub), Fernando Cabrera (European Spanish dub)

"I don't understand why in this group, I never get my way."

Leonard's roommate. A child prodigy, he graduated from college at the age of 15 from East Texas and specializes in Theoretical Physics. Supposedly the smartest of the guys, but he only ends up dominating arguments and debates (both in science and in nerd trivia) because he's too stubborn to quit and resorts to crazy logic to win. His dedication to science and geekdom is so complete that he has almost no interest in social skills, certain pop culture elements (current trends, celebrity gossip, etc.) or even romance. He thinks he's superior to... well, to everyone.

---

A-E

• Abandoned Catchphrase: Sheldon adopted the habit of making some surprising statement, and when met with surprise, reveal that he was joking with the catchphrase, 'Bazinga!' He also used it once when successfully pranking Leonard. He abandoned it after a while.
• Academia Elitism: Sheldon frequently mocks Howard for going to M.I.T. and Leonard for going Princeton.
• Accent Relapse: Jim Parsons manages to keep his natural Texan drawl under control but there are a few times it slips out, typically done in character with Sheldon who is also from Texas. These relapses are rather cleverly worked into the story — it is heavily implied that Sheldon affects his rather colorless normal accent, and that his natural Texan accent creeps back into his speech when he is too angry, distressed or occasionally too drunk to hide it. For example, when Sheldon is locked out of his apartment and Penny offers to let him eat his food in her apartment:
  Penny: Sure, why not?
  Sheldon: [accent relapsing] Sure, why not? And after the sun sets, we can all go pile up in my pickup truck and go skinny-dipping down by the the crick (creek)! Cause today's the day to stop making sense!
• Accidental Hero: On multiple occasions. For instance, he stopped Leonard from giving up the secrets to the experimental rocket fuel to a spy posing as his date, by barging in and complaining about them trying to sleep together without warning him 24 hours in advance, as their roommate agreement required. He also has a lack of social filter, such as that he will attempt things that others are too timid to do themselves and by all means shouldn't work, but sometimes does. Especially when he nails an Armor-Piercing Question on Leonard, it tends to prove beneficial to him in the long run by forcing him to confront that option.
• Actually Pretty Funny: When he laughs, he only does it for a second before resuming to his usual serious, stoic self but when Penny imitates Leonard, he actually could barely resist the urge to laugh at it.
• Adaptational Nice Guy: He's much less of a jerk as a kid in Young Sheldon, where he's annoying in a naïve way rather than in deliberately rude way.
  • In Young Sheldon, he's still full of himself and a know-it-all, but he doesn't feel the need to insult and belittle other people all the time like he does in The Big Bang Theory. Also, he mostly respects other scientists in Young Sheldon, while in The Big Bang Theory, he rarely shows respect for any of them, aside from Stephen Hawking.
  • In Young Sheldon, he may be spoiled by his mother and grandmother, but he's much less demanding than in The Big Bang Theory and he doesn't expect his family members to always follow his orders, in contrast to the way he acts in The Big Bang Theory.
• Aesop Amnesia: Sheldon doesn't really learn lessons because he's too stubborn to believe he has anything to learn. Even in Young Sheldon, the older Sheldon narrating, who is eventually confirmed to be from some time after the events of the original series, shows he never fully grasped the lessons he "learned" from when he was a kid, such as believing he was never irritating or abusive to his friends and loved ones.
• Affectionate Nickname:
  • His mother and sister call him "Shelly", and only they are allowed to refer to him as such.
  • His grandmother calls him "Moon Pie" and he calls her "Meemaw"... and nobody calls him Moon Pie but Meemaw!
• Afraid of Blood: Sheldon faints at the sight of his own blood after cutting his thumb while attempting to dissect a brain. He later removes the bandage to prove to Penny how serious the wound was and promptly faints again.
• The Alcoholic: He inherits the gene from his dad, who drank himself to death. It's implied that he's fully aware of it, as he makes a concerted effort not to drink, but on the few occasions that he does, he does not stop.
• All of the Other Reindeer: Had almost no friends as a child (and even his teachers hated him) because of his Insufferable Genius tendencies. He did find a friend in Tam, though. It got to the point in the episode "German For Beginners and a Crazy Old Man With A Bat" that the congregration banded together to raise the money to help him go to Germany for the summer-because they all wanted him gone.
• All Take and No Give: Sheldon is very selfish and demanding, and often tries to manipulate things to where he always gets his way and is only interested in things that concern himself. This is easily seen in his various contracts and agreements, which he admits he creates to heavily favor himself and force others to help him. Though he will always deny this if he is called out on it, believing that minor, inconsequential things and empty gestures he gives to others is more than enough of something he "gives" in return. If he is ever denied something then he will hypocritically accuse everyone else of being this, saying they are selfish and never let him have his way.
  Howard: Sheldon, my mother is on her deathbed and my fiancée is grief-stricken over putting her there. I’m not taking you home.
  Sheldon: Will you at least go with me to the restroom here, so you can open the door and flush the urinal?
  Howard: No!
  Sheldon: This might be a good time to point out, Howard, that friendship requires a certain give and take!
• Animal Motif: In earlier seasons he was compared to a praying mantis due to his mannerisms and physique. This has long since been phased out.
• Annoying Patient: Sheldon suffers from severe social ineptitude, as well as mild hypochondria, turning him into a literal nightmare to be around when he's ill. He also exhibits no shame for any of his behavior until 9 seasons in.
• Anti-Hero: He mostly cares about himself and, intentionally or not, he belittles his friends on a regular basis. He's also arrogant, strict, petty and demanding. Despite this, he does genuinely care for his friends, and a hybrid of that, lack of malicious intent behind his actions, child-like traits and multiple Pet the Dog moments stop him from becoming unlikeable.
• Attention Deficit... Ooh, Shiny!: Sheldon usually has issues with maintaining focus when he is unable to work at the university. He goes from one project in the morning to the third or fourth by the time Leonard gets back home.
• Aw, Look! They Really Do Love Each Other: Has these moments not only with Amy, but with all of his friends and family. After an episode focusing on his jerkish tendencies, he almost always has at least one Pet the Dog moment to show that he cares for them. Even despite his Sibling Yin-Yang with Missy, she admits at the end that she's very proud of him, and tells all of her friends that her brother's a rocket scientist. Naturally, Sheldon gets upset at the "rocket scientist" bit, but still. For all the bickering he does with Leonard throughout the series, we find out in Young Sheldon that he names his eldest son Leonard, although his narration references Leonard Nimoy.
• Babies Ever After: In the Season 4 premiere of Young Sheldon, Sheldon says that his high school graduation was the best graduation party until his son's graduation party, Leonard Cooper. He wanted to name him Leonard Nimoy Cooper but Amy only let him keep the Leonard part. Celebrity name aside, it's obvious who he wanted to name his first son after.
• Bad "Bad Acting": His "Fun with Flags" show has him delivering his lines in a complete monotone tone of voice and sounds like a speech synthesizer. He also directs his lines directly at the camera, and his body language is cold and uninviting.
• Bad Liar: If he thinks too hard, it's virtually impossible for him to maintain a lie, keeping secrets drives him insane. But if he works up an overcomplicated backstory to the lie then he can manage it okay, but that requires some prep work including falsifying evidence and sometimes a Facebook profile. His trouble is knowing the proper scale of lying — his intricate preparations would be rather good lies for a government intelligence agency. In terms of deflecting attention from a white lie Leonard told to avoid having to watch Penny sing, it was way over-designed with the belief anything less would fall apart. If it's an improvised deception in the moment, he too can stumble along.
• Been There, Shaped History: In Young Sheldon episode "A Patch, a Modem, and a Zantac", it's shown that Sheldon's notebook inspired Elon Musk to successfully land a rocket on a drone ship in the Atlantic Ocean on April 8, 2016.
• Beta Couple: Although his relationship with Amy is a complex one, it is significantly more stable then Leonard/Penny. This is accurate to Asperger syndrome (although his attitude to sex is not). If he didn't believe a relationship with Amy would last, he wouldn't bother. Their relationship continues because Amy feels exactly the same way.
• Big Damn Kiss: In the middle of an annoyed rant about romance, the normally asexual Sheldon actually initiates a kiss with Amy in "The Locomotive Manipulation." It had been out of spite, but then he realized he actually liked it.
  • Gets one in Season 9 with the kiss he shares with Amy after they get back together.
• Big Ego, Hidden Depths: Sheldon may qualify as many of his breakdowns show that while underneath his ego, he is in many ways still just a little kid who doesn't understand the world and still hasn't recovered from multiple traumatic incidents that occurred during his childhood, he does genuinely care about his friends and several episodes have implied that his ego stems from some sort of coping mechanism (he tries to reason that his childhood bullies hurt him cause they were jealous of him).
• Big Guy, Little Guy: The Big Guy to Leonard's Little Guy. Sheldon is 6' 1" (1.86 m) and towers over the 5' 5" (1.65 m) Leonard.
• Birthday Hater: Sheldon has some mental scars from past birthdays experiences relating to his general aversion to socialization. Subverted as he's actually willing to attend Amy's birthday in "The Opening Night Excitation."
• Black Face: In an episode of Fun with flags, LeVar Burton stops by again:
  Sheldon: Since you're here I'd like to get your opinion on something, in honor of Black History I portrayed George Washington Carver in a loving tribute that my roommate called "wildly racist." What do you think? [shows Burton a tablet] Hi, my name is George.
  LeVar Burton: Oh, hell no...
  Sheldon: See Leonard, it's not racist.
• Blue-and-Orange Morality: In regards to his ability to keep a secret at least. Despite claiming that he simply can't keep a secret, this isn't actually true and instead he has a very complicated view on the subject. On the one hand, it is shown often that being told that he needs to keep something a secret causing him to act even more odd and go to extreme lengths to avoid telling it. He also fixates on the possibility of someone asking him something that relates to the secret, even when told that nobody will ask him about it. On the other hand, it's often shown that if keeping secrets is tied to some sort of contract (real or imagined by him) he's able to keep it hidden and resist worrying about revealing it. Young Sheldon also showed that confessing to Tam helped him deal with the anxiety about keeping a secret from Mary, suggesting that he simply need to tell the secret to anyone to get it out of his system. He's also able to keep secrets if it's something he already knows, as opposed to being told or finding out, which mean he can certainly lie to others about that.
• The Bore: Frequently. His flag podcast is really cold and colorless, and he often railroads the conversation onto topics that only he finds interesting (such as railroads). Sheldon, being the way he is, takes the disinterest as signs of his audience's intellectual inferiority.
• Brainy Brunette: A genius with dark hair.
• Book Smart: He attended high school at the age of 9, showing Insufferable Genius tendencies even towards his teachers.
• Break the Haughty: His inflated sense of entitlement and superiority often end up putting him through a thorough Humiliation Conga. Subverted in that he never loses his arrogance, no matter how hard he may have been humiliated. He actually faints when Dr. Stephen Hawking points out a small mathematical error in the paper Sheldon gave him. Played within the series finale when even AMY admits Sheldon is very hard to deal with at times. He takes it to heart and thanks his friends in his Nobel acceptance speech. Whether or not the lesson will stick with him this time is up for debate.
• Breakout Character: He quickly became the most popular and influential character in the series and is thus far the only character to receive a spin-off or any kind of additional franchise.
• Brilliant, but Lazy:
  • He's certainly very smart and works very hard on things, but has actually accomplished very little, especially compared to Raj and Howard, who have both been at the center of major stories about their accomplishments. It may be a result of Informed Ability, seeing as his offscreen resume is fairly impressive.^note He has won numerous accolades such as the Chancellor's Award, the Stevenson Award (at fifteen!), received an NSF grant, and was invited to present his findings on Bose-Einstein condensates. Also, of all the CalTech employees on the show (i.e., everyone except Penny and Bernadette), he is furthest up the career ladder — his job title is Senior Theoretical Particle Physicist, implying that he is the highest-ranked or at least a highly-ranked such scientist on the faculty. Furthermore, in The Bat Jar Conjecture, he was able to match the combined talents of Leonard, Raj, Howard and Leslie Winkle on his own. If he had just been able to put aside his pride, he would have won.
  • Averted in Season 7. In "The Romance Resonance", he discovers how to synthesize a new heavy element, it doesn't get him mainstream fame, but it quickly becomes popular in the scientific community to the point the cafeteria applauded him. Unfortunately, it turns out that he stumbled across the discovery unintentionally after misreading a chart and making a mathematical error. And then it comes out that the team that tested his hypothesis faked their results, so he didn't "discover" anything after all.
• Bunny-Ears Lawyer: Averted. It's made clear that, however smart he may be, he's nowhere near as valuable or talented as he thinks and he's been fired with little issue at least once, although comments from President Siebert seem to suggest that there are at least some people on the university board who feel he plays this trope straight.
• Brutal Honesty: Due to his problems with lying, Sheldon normally tells the truth in the most brutal way possible, and then won't realize why they're offended. It caused a lot of problems for his family when he was a kid. Worst of all is he does not learn to stop and even takes offense when people try to do it to him.
• Butt-Monkey: Often on the receiving end of a lot of humiliation and punishment even if not to Leonard's extent. Not that he doesn't bring it on himself, though. He's an even bigger one in the prequel series Young Sheldon from being bullied by his bratty sister Missy to dealing with abusive neighbors.
• Calling Your Bathroom Breaks: Socially awkward in this department doesn't even begin to cover it.
  Sheldon: [sigh] I'm sorry, I'm not renting this room out to hippies.
  Leonard: Okay, okay, around 8:00.
  Sheldon: Hmm, I can't do that, is 7:30 okay?
  Leonard: Yeah, okay, whatever!
• Cannot Keep a Secret: Considering that he’s a Bad Liar, he either slips into I'll Never Tell You What I'm Telling You! or comes up with needlessly elaborate lies that fall apart under their own weight. However, if he is given a pre-prepared and reasonably concrete deception he can muddle by.
• Cannot Tell a Lie: Whenever he tries to lie, he exhibits really obvious nervous facial tics.
• Can't Hold His Liquor: He almost never drinks casually, but it doesn't take much for him to lose it, once getting tipsy after only using tequila as a mouthwash. In addition, there have been a few times he was unaware of what he was drinking because it was spiked. In Season 7, he begins drinking more commonly at some social events, although he is still not particularly interested in doing so, nor does he seem to enjoy it that much. Never the less his tolerance seems to have increased with his change. Luckily, he's quite a fun drunk.
• Catchphrase:
  • "Bazinga". (Dropped this somewhere around Season 6).
  • There's his, "Excuse me!" when he wants to argue a point or just disagrees with something.
  • [Knock, knock, knock] "Penny." [Knock, knock, knock] "Penny." [Knock, knock, knock] "Penny." Sheldon even gets a little annoyed when Penny opens the door before he finishes.
  • "I'm not crazy. My mother had me tested."
  • He often asks "In what universe..." to something he wants to argue about.
  • "That's my spot."
• Celibate Hero: As far as being openly contemptuous of any kind of sexual desire. At least until season 9 when he consummates his romance with Amy and begins a sexual relationship with her in addition to a romantic one. He admits to finding the sexual experience more enjoyable than he thought he would.
  • Sheldon is conspicuously uninterested in sex, and is one of those rare TV characters whose asexuality is made more or less explicit In-Universe.
    Penny: I know this is none of my business, but I just... I have to ask: what's Sheldon's deal? Is it girls...? Guys...? Sock puppets...?
    Leonard: Honestly, we've been operating under the assumption that he has no deal.
    Penny: Come on, everyone has a deal.
    Howard: Not Sheldon. Over the years, we've formulated a number of theories about how he might reproduce. I'm an advocate of mitosis.
  • He's familiar with the concepts of physical or romantic attraction, but doesn't apparently experience those things himself. Any time he "clicks" with someone in a romantic way, it is always juxtaposed with a common scientific enthusiasm. While the possibility of sexual attraction has appeared from time to time (when Amy kisses him in Season 4, he says "Fascinating", which could indicate that he found the experience at least interesting), he is written largely as someone who places intelligence and science first and mocks his friends for not doing the same.
    Leonard: Sheldon, think this through: You're going to ask Howard to choose between sex and Halo!
    Sheldon: No, I'm going to ask him to choose between sex and Halo 3. As far as I know, sex hadn't been upgraded to include hi-def graphics and advanced weapon systems.
    Leonard: You’re right. All sex has is nudity, orgasms, and human contact.
    Sheldon: My point.
  • In a Season 3 episode, Penny falls in the shower and breaks her arm. She calls Sheldon for help on the sole basis of knowing that the sight of her naked would literally do nothing for him. In fact, Sheldon spends more time whining about how she could have avoided the accident with proper shower padding and the possibility of getting injured while driving than noticing her nude attractive body at all. Although he does admit to taking a peek after she earlier asked him to close his eyes while dressing her.
  • With the introduction of Amy as a Love Interest in season 4, it has been depicted solely as Single-Target Sexuality; he connects with Amy in a way he hasn't with anyone else and they become a couple in season 5 when he realizes he wants a relationship with her. Throughout the relationship, he shows signs of jealousy (when it looks like she's interested in someone else) and depression (after they briefly break up). In Season 7, Sheldon gives a "Take That!" Kiss to Amy to mock her idea of a "romantic weekend", then suddenly moves in closer, puts his hands on her waist and holds the kiss. Upon pulling away, he shows a surprised reaction, proving he unexpectedly enjoyed it. While they had kissed several times before, it was largely Amy surprising him with affection. This is the first time Sheldon initiated the kiss and him lingering was a sign of finding it pleasurable. Later in their relationship, they seem to have no issue making out while on dates. Although Amy remarks how it took her several years to get him up to the level of making out.
  • The finale of Season 8 shows that Sheldon was willing to propose to Amy before she broke up with him. Given his reliance on "social convention", he likely would have had a proper honeymoon with her. He finally proposes to Amy in the season 10 finale, as she had left town for a 3-month long project and he began spending time with Ramona Nowitzki, a colleague who showed romantic interest in him. When she shocks Sheldon with a kiss, he immediately flew across the country to see Amy and propose; he found out she was the only woman for him.
  • He consummated his relationship with Amy in "The Opening Night Excitation", spending part of the episode debating on an appropriate birthday gift to give her. This happened shortly after they broke up but got back together and he wanted to prove to Amy how much she means to him. Both really enjoyed the experience, but he viewed it as a special occasion and says he looks forward to having sex on her next birthday, making it their yearly tradition. Exceptions seem to be made on particular occasions; after co-working on an experiment melding skin samples between him and Amy that produce a simple neural network, he became interested in getting her pregnant, even telling Amy he would be up for having sex with her right there in the lab (she refused on principle and not being ready for kids). In season 10, she was leaving for a fellowship at Princeton for 3 months and he offered sex as a special farewell present before she left. (This turned comedic when Raj, Penny and Leonard hear Sheldon and Amy vocally enjoying themselves from across the hall).
  • Furthermore, while the gang firmly believed Sheldon "had no deal" his relationship with Amy proved otherwise. Two main things that Sheldon particularly likes is when Amy role-plays as his favorite book characters (i.e., Harry Potter characters) or, especially, when she mentions scientific facts and information related to a conversation they're having. On their honeymoon, Amy and Sheldon are having a conversation, and Amy casually mentions a scientific fact related to it. Sheldon suddenly grabs Amy's hand and begins walking them away. Amy asks what he's doing and he answers that he's taking them back to their hotel room and that she's "going to say that again but naked". Amy has a shocked but happy facial reaction.
• Celibate Eccentric Genius: At least, before Amy Farrah Fowler came along and he grew to care for her enough to want to express that love in season 9. Even his dynamic with Amy isn't particularly conventionally romantic, but it works for them.
• Character Development: Sheldon hanging out with Penny and the gang leads him to become more and more human. Three particular Season 5 episodes involve him pushing out his personal boundaries, discovering that his rigid scheduling to regulate his life doesn't need to be so inflexible and his life won't collapse if he does things a little differently now and then. Shortly into his relationship with Amy, he was reluctant to keep to his end of the agreements in the Relationship Agreement. In a later episode, when Amy is sick, after some initial hesitation, he agrees to uphold the agreement and take care of her and does go vigilantly. During Season 6, he notes that he has become more comfortable with physical contact and admits that someday he and Amy might be physically intimate (this shocks Penny who can barely hold in her reaction). In Season 7, he seems noticeably calmer, slyer, and quicker than before. In Season 9, he DOES get physically intimate with Amy as a means of showing the extent of his love for her. In an episode of Season 12, while watching a recording of his father coaching high School football, he considers that as different as he and his father may have been, there have been parts of themselves that are similar.
• Characterization Marches On: Considering the sheer number of quirks he acquired after the first few episodes, it's somewhat of a shock to see him in the early stages. Sheldon wasn't quite as socially inept or uptight in earlier episodes and may not even have been established as asexual yet. He was still an arrogant jerk, but more of a friend ribbing another instead of having a huge ego mixed with neurodivergence. As such:
  • Asexuality: He casually refers to Penny being beautiful and immediately recognizes Leonard is attracted to her, seems to (mildly) compete for her attention and when they visit a sperm bank, Leonard makes an off-hand comment that Sheldon is a "semi-pro", the implications in such a context should be obvious.
  • Social Skills: He advises Leonard that discussing bowel movements isn't appropriate when he invites Penny to lunch. As early as the second episode it becomes a Running Gag Sheldon rarely understands sarcasm. In the first episode, nearly all of his jokes are sarcastic quips at Leonard's expense. In later episodes, it becomes a challenge to get Sheldon to admit that he's wrong, regardless of whatever outrageous thing he's done or said. In the second episode, although he still believes that cleaning Penny's apartment without her permission was the right thing to do, he offers a sincere apology to her face after some prodding by Leonard. However, he continued to use sarcasm and dry snark, meaning he probably understands sarcasm, just can't detect it readily.
  • Language: His Catchphrase "Bazinga" did not show up until the late second season. He was also not the first person to use "coitus" as Spock Speak for sex (that was actually Howard), and in fact simply used the word sex. While he didn't have a potty mouth, he did use swear words rather judiciously a few times ("Oh gravity, thou art a heartless bitch."), in later seasons he would either censor himself ("I wanted to avoid offending the ho's"), others ("Cockamane?" "I felt uncomfortable with the word Leonard used") or use old fashioned terms ("ninny").
• Chastity Couple: He and Amy initially agreed there would be no physical relationship, but over time Amy developed into wanting one. While he has no interest in it (and doesn't recognize certain behavior, like helping her bathe and rubbing Vapo Rub on her chest is arousing to her) he has admitted to her and others that she influenced him and he considers theirs a deeply intimate relationship even if they aren't physical. Their relationship finally became physical as of "The Opening Night Excitation" where he and Amy agree to a yearly tradition of having sex on her birthday. After their marriage in season 12, however, this is no longer the case.
• Child Hater: Sheldon is this, likely stemming from having been bullied so much as a child. When he tries to do a shooting for the Professor Proton show reboot, he instead ends up talking about a dangerous experiment, very complicated math and admits that he doesn't even know how to talk to little kids due to his social awkwardness. Sheldon even states that he doesn't like kids when Howard offers an invitation to his daughter Halley's first birthday party.
  • Subverted in one episode where he actually did try to make friends with a little kid, only for Leonard to forcibly walk him out likely to avoid the possibility of certain implications.
  • Later averted in season 12, Amy manipulates him into developing an interest in kids in order to convince him to eventually have children with her. It works, and Sheldon decides that he wants kids with her... fifteen of them (Amy makes it clear she only wants two). In Young Sheldon, a narration by the adult Sheldon reveals that he and Amy do indeed end up having children together.
• Child Prodigy: While he definitely was, attending college at 11 and getting his first of two Ph.Ds at age 16, it's possible he's a deconstruction of the concept. His intelligence vastly alienated him from his family, gave him a big ego, made him highly neurotic and socially inept, and though it may or may not be related to his childhood brilliance he's also something of a man-child.
• Chosen Conception Partner: To Amy, who propositions him for sex under the explanation that it's their duty to sire future geniuses.
• Clock King: Sheldon is obsessed with scheduling everything, planning things, has his daily schedule planned out and memorizes and tries to plan other people's schedules. He even unironically considers things related to planning, order, schedules, rules, and organizing to be a fun experience. He even one mistook Howard and Bernadette talking about spending all day at the zoning office for bragging about a "fun day".
• Cloudcuckoolander: Far too many examples to list. Sheldon has a tendency to come up with strange ideas and plans, which affect everyone around him. Such as trying to stay awake for days (to work on a scientific problem), stepping in into the roles of busboy and waiter at the Cheesecake Factory without bothering to notify his new employers, tracking down James Earl Jones to convince him to co-found a comic book convention, etc.
• Clueless Chick-Magnet: Sheldon has gained not one, but two devoted groupies. As well, he ignores a girl who actually goes into his room and sits on his bed, and unwittingly manages to pick up a gay man. After Sheldon ends up charming Raj's date (a successful dentist), causing her to leave for the date with him instead, he then completely fails to understand why he would see her again.
  Sheldon: Why would I see her again? I have a dentist.
• Color-Coded for Your Convenience: The shirts Sheldon wears, taken from Green Lantern comics, can sometimes indicate his moods.
  • Red = Anger
  • Orange = Greed
  • Yellow = Fear
  • Green = Courage
  • Blue = Hope
  • Indigo = Compassion
  • Violet = Love
• Comically Missing the Point: Due to his self-interests and lack of social skills, he often ignores or completely misses the point of what anyone else is talking about. This sometimes includes him completely changing the subject out of the blue, because either the old one does not interest him, or he’s using Insane Troll Logic to get to the wrong conclusion.
• The Comically Serious: In fact, it's pretty much his entire shtick (aside from neurosis, his uptight and fussy personality, and love for trains).
• Commitment Issues: Sheldon struggles with committing to Amy and has significant problems moving forward in their relationship. The issue stems from having previously thought of himself as a Celibate Eccentric Genius who is above romantic notions, and having an aversion to change. In one episode, both Leonard and Amy decide to move too fast for their partners and put moving in on the table. Sheldon and Penny are forced to confide their hesitations about it to each other.
• Consistent Clothing Style: Sheldon always wears comic book t-shirts. Oddly, he dressed in button-down shirts as a child.
• Control Freak: He regulates when his roommate can use the bathroom. (8:20 am, since you ask).
• Crazy Cat Lady: Gender inverted. In "The Zazzy Substitution" (Season 4, Episode 3), Sheldon and Amy break up. He tries to fill the void in his life by adopting 25 cats. This is treated as disturbing.
• Crazy Jealous Guy: If any guy shows minor interest in Amy Farrah-Fowler.
  Sheldon: [karate-chops Leonard] She is NOT for you!
• Crazy-Prepared: His flat is ready for every catastrophe.
• Crippling Overspecialization: He's so focused on science that that's the only thing he's smart at; everywhere else he's completely clueless. He can't look after himself and needs someone like Leonard or Penny to take care of him and keep him in check, has low emotional intelligence, and he has very poor social skills which gets him into too much trouble.
• Creature of Habit: Is called this and Penny uses this against him during their feud.
• Cuckoosnarker: Though Sarcasm-Blind, he tends to make sarcastic (or Innocently Insensitive) quips at his friends and colleagues (and pretty much everyone).
• Cultural Rebel: He's pretty far removed from the stereotypical Texan he was raised to be. He also affects an accent he perceives to be more educated, slipping back into his native Texan drawl when very angry or distressed.
• Cuteness Proximity: Falls into this when he started out naming the plethora of cats after scientists until he got to Zazzles.
  Sheldon: I was going to name him Hermann von Helmholtz, but he's so... Zazzy.
• Cut Lex Luthor a Check: Sheldon's eidetic memory would make him very successful in a variety of conventional career fields, and in one episode we see he's very courteous and helpful when he takes it upon himself to aid customers at a computer store. Too bad he's so arrogant he sees such fields as beneath him and is dedicated to theoretical physics.
• Deadpan Snarker: Further in keeping with the depiction of Asperger Syndrome; this is the type of humor that Aspies are most at home with.
  Leonard: Sheldon, how could you just sit there and let [Howard and Raj] spy on me?
  Sheldon: They were clever, Leonard. They exploited my complete lack of interest in what you were doing.
• Depending on the Writer:
  • The degree of Sheldon's irreligion and views on God seem to be this. While it's clear that he doesn't share his mother's Christian beliefs, he seems to vary between atheism, agnosticism, apatheism and even acknowledging God and/or Jesus' existence at times.^note I Most scholars, even secular and atheists agree that Jesus existed historically. Whether he was divine or not is best discussed elsewhere. In Young Sheldon, he is much more vocal about his lack of belief, likely due to growing up in the highly religious state of Texas, whereas in The Big Bang Theory, he lives in the more secular state of California.
  • How deliberate Sheldon is about his abrasive behavior. Some times he's made aware of how obnoxious he's being, point blank doesn't care and acts entitled to keep going and can even Kick the Dog just for his own petty pride or amusement. Other times it's clear that he's being Innocently Insensitive and honestly means well by his friends. And still other times he's in the middle of the road; demanding and irritating but acting by a governing code that he won't deviate from even if it inconveniences himself and willing to follow said code for sake of others rather than himself.
• Dirty Coward: In the episode where he and Raj were in the steam tunnels, and he abandons Raj there when some rats show up. Later, Raj gives him a What the Hell, Hero? speech. He even admits to it when being called out on it by Amy. Basically Sheldon is a very poor person to rely on because he's either too selfish or short-sighted to do anything heroic.
• Disability as an Excuse for Jerkassery: Will often state that he doesn't mean harm whenever people call out his obnoxious behavior. Thing is though, it's pretty clear that Sheldon enjoys being a bully, since he acts more respecting and thoughtful towards individuals like Prof. Hawking and his grandmother.
• Ditzy Genius: He's a brilliant scientist, but is absolutely, painfully clueless in almost every other aspect of life. He overanalyzes things, making him unable to answer simple and easy questions (especially if it's not related to engineering, physics, calculus or statistics). He interprets Penny saying "Oh, I see" as the acronym OIC, disputes a DMV written exam question for trying to define a standard car length claiming that cars are obviously of varying length and misconstrued Leonard's drawing of a chocolate-chip cookie in Pictionary as a quark gluon plasma. He stubbed his toe in a revolving door on the way in the hospital when he kept going around and around because he got confused by the lobby's plant.
• Don't Explain the Joke: Sheldon seems to think that a joke can only be funny if it is explained. Whether he is the one telling it or he hears it from someone else he will give a quick explanation of why it is funny, or ask for clarification on it while simultaneously explaining it himself if he is not entirely sure it is a joke, before laughing at it, much to the annoyance of everyone else.
• Dramatically Missing the Point: Though his cluelessness of others and lack of social awareness is usually played for laughs as Comically Missing the Point, there are times where it is played very seriously as this instead.
  • In Young Sheldon, he once caused a fuss because a company began to produce his favorite bread cheaply to save money. He began to protest and start petitions to make it better, but when he ended up on the news he ended up accidentally implying that he supports Communism when describing how bread should be produced, not knowing what this actually meant beyond "it will get good bread again". He spends the rest of the episode acting like his bread is the main focus of discussion, not understanding what he has just done to his family or how they are suffering because of it.
  • His breakup with Amy was caused because even after five years together he was more focused on his personal stuff than her, and when he continuously bugs her about getting back together, to the point of openly insulting her, he just makes her angrier until she officially breaks up with him.
  • In the series finale of The Big Bang Theory, he ends up pissing everyone off due to being focused on his Nobel Prize. This includes him not caring about Penny being pregnant and snapping at Howard for being worried about being away from his kids. When Sheldon acts like his friends are the selfish ones for wanting to abandon him and Amy, Amy sets him straight by telling him they are only doing it because he broke their hearts, and they have only tolerated it until now because he never actually means to.
• Dumbass Has a Point: He is largely clueless with regard to relationships but sometimes does have an impressive insight with those.
• Dysfunctional Family: He has several bad memories of his parents fighting and that is reflected in some present events (he returns to being 10 when Leonard and Penny fight). It is commonly implied he grew up in a very unstable home. He also commonly implies or even outright states on occasion that his father was a severe alcoholic. He had a very poor and somewhat abusive relationship with both his siblings. There are some other things where he considered his parents to be Abusive Parents but they were just trying to treat him like a normal child (he wanted a titanium centrifuge for his birthday, they gave him a motorized dirt bike). He also reveals that his father cheated on his mother. Likely this is exaggerated as we see in Young Sheldon. Likely he didn't understand what was going on and being so literal-minded he probably still can't understand it.
• Entitled Bastard: He always expects his friends to always be there for him and forgive him no matter how much he mistreats and belittles them. When Leonard doesn't invite him to Switzerland to see the Super Collider, he unfairly gets angry at him and wrongly blames Penny even though his poor treatment of Leonard is the reason why he wasn't invited in the first place.
• Even Bad Men Love Their Mamas: Sheldon's mom is the only one who can override his irrational behavior. He also seems quite devoted to his grandmother, or "Meemaw", as he calls her.
• Even Nerds Have Standards: Sheldon has a devout interest in a lot of staple sci-fi franchises (Star Wars, Star Trek, Doctor Who to name only a few) but openly professes disdain for Babylon 5 in "The Staircase Implementation".
• Even the Guys Want Him: Played for Laughs. In "The Barbarian Sublimation", Sheldon accepts Leslie's hypothesis (Penny needs a sexual relationship) and proceeds to ask the first guy (Blaine) he sees if he is interested in a sexual relationship and his phone number. Sheldon doesn't realize that Blaine is probably gay as he accepts Sheldon's requests. Everybody but Sheldon realizes what happened.
• Everyone Has Standards:
  • While he doesn't like Priya for exploiting the Roommate Agreement to his disadvantage, he is disturbed by Amy offering to kill her.
  • While it's mostly about losing the bowling game, he's genuinely disgusted that Wil Wheaton intentionally sabotaged Leonard and Penny's relationship just for a better chance to win.
• Evil Genius: Sheldon occasionally invokes this on purpose. Leonard has already noted that Sheldon's "one lab accident away from becoming a supervillain".
• Eyes Always Averted: In the Flashback to when Leonard and Sheldon first met, Sheldon makes very little eye contact. It's a little off-putting and not immediately noticeable, but adds to just how much better he's become in social situations.

F-J

• Fatal Flaw:
  • Pride. So. much. Pride. Sheldon is convinced that he's the smartest person on the planet and would avoid 90% of the problems he faces if he was just willing to admit he's not as smart as he thinks he is. He's shot himself in the foot and cost himself more than a few wins by not being willing to concede that someone could outdo him.
  • Lack of Empathy. Sheldon tends to say things in the bluntest manner he can without any concern about how others feel about it because he honestly doesn't care if he offends them or not. Typically he's Innocently Insensitive about it but it still rubs people the wrong way and the fact that he never stops doing it strains his friendships.
• Fictional Fan, Real Celebrity: He is enamored with both Stephen Hawking and Leonard Nimoy. He is thrilled to be able to play "Words with Friends" with the former (until he lets Hawking win, and Hawking calls him out on it), and goes absolutely nuts when Penny gives him a napkin used by the latter while she's working at The Cheesecake Factory.
  Sheldon: [in shock] I possess the DNA of Leonard Nimoy!
• The Finicky One: He has a thing for making people sign written agreements, is something of a germaphobe and is very picky about where he sits.
• First Kiss: His first kiss with Amy was in Season 4's "The Agreement Dissection" when a drunken Amy kisses Sheldon, and he deems it "fascinating." She also kisses him when he buys her a tiara in Season 5, after they've started dating. However, their Big Damn Kiss is in "The Locomotive Manipulation" (Season 7, Episode 15), the first time Sheldon initiates it and they both enjoy it.
• Foil: Primarily for Leonard, but can be this for Raj and Howard. Many of his nerdy interests and behavior can be seen as somewhat of an extreme version of the other three. While nowhere near as intolerable as Sheldon, Leonard, Raj, and Howard do show a sense of intolerance that can irritate other characters.
• Foolish Sibling, Responsible Sibling:
  • When they were young, he was the Responsible to Missy and Georgie's Foolish. He was always an extremely smart goody two shoes while both his siblings were Book Dumb and careless.
  • It's completely subverted with respect to Georgie. When he appears in Season 11, he turns out to run an extremely successful tire business, and it's also revealed that he stepped up to help run the Cooper household when their father died and their mother fell into depression over it. Given Sheldon's particular eccentricities, Georgie ends up looking like the Responsible sibling between the two and is arguably richer, more successful, and certainly better adjusted to the world.
• For Want Of A Nail: Discussed in "The Cooper Extraction", where we see that Leonard not moving in with Sheldon meant he would've moved in with Raj and not cared about meeting a woman, letting himself go. Without Sheldon, Leonard wouldn't have had a foil to play his awkwardness off of and Penny would've turned him down from the get-go. Amy would've remained a social outcast, miserable and desperately seeking friends. No Leonard and Penny means that Bernadette never gets set up with Howard, who remains with his mother and eventually goes Psycho on her. Lastly, without Leonard in the picture to circumvent her theorized high sex drive, Penny would've made many advances on Sheldon, likely have given up, then end up settling for an idiot like Zack.
• Four-Temperament Ensemble: The Choleric. He insists on taking decisions for the group, making him the de facto leader, he is devoted to his work, he is a goal-oriented person (who will go to any lengths to achieve said goals), he is typically overconfident, passionate for the things he cares about. He also has the flaws of the type such as being overly Bossy, needlessly stubborn, vindictive, insufferably arrogant, insensitive to the feelings of others, and rude to other people.
• Freak Out: The sheer quantity of changes he experiences in Season 7 is too much for him to handle. They include his new field of work, Leonard and Penny getting engaged, the possibility of Leonard moving out, Stuart's comic book store burned to the ground, him getting more intimate with Amy, the death of Professor Proton and so on... Sheldon goes beyond his breaking point and leaves on a train to straighten his ideas.
• Freudian Excuse:
  • He reveals to Penny that the reason he knocks three times is that When he was a teenager, he entered a room without knocking, to find his Father committing adultery. Him knocking is to give whoever is in the room a chance to get dressed.
  • The real reason Sheldon hates geology is revealed on Young Sheldon: it's because it reminds him of his break with childhood friend Libby, who was a big geology fan, and even got Sheldon and Tam hooked up on it for a while (although Tam was actually more hooked up on Libby). Sheldon broke up with Libby because he disliked her for being his babysitter, wanting to appear more like a mature boy, which she told to him and Mary Cooper when Libby and Mary were getting acquainted before she took Sheldon and Tam by car to Houston to watch an IMAX movie, while Libby broke up with Tam because he tried to hit on her while they were watching the movie without Sheldon, since he ended up not going, and she did not like it.
  • Young Sheldon also reveals the real source of his disdain towards engineering, which he takes out on Howard. He had a very strict professor for an engineering class that constantly rejected and tore up his work for being wrong, and unlike his other professors, he would not help him by telling him what he was doing wrong. When Sheldon finally figured it out he arrived late to class and was locked out, with him declaring he hates engineering.
  • Paige having fooled him into drawing a moustache on his lip while he thought they were kissing in "A Second Prodigy and the Hottest Tips for Pouty Lips" and punched him hard in the face in "Bible Camp and a Chariot Of Love" turned Sheldon off from love for a long time, until he met Amy .
• Friendship Denial:
  • In the episode "The Excelsior Acquisition", we have Sheldon and Penny introducing themselves to Stan Lee.
    Penny: Hi. I'm Penny. This is my friend Sheldon.
    Sheldon: We're not friends at the moment. Depends on how this goes.
  • In the episode "The Septum Deviation", Leonard undergoes an operation to correct his nasal septum. Everyone is cool with it apart from Sheldon, who is so unable to cope with the possibility of Leonard suffering potentially lethal complications that he comes to the hospital as well, in spite of his fear of germs. Later, on the couch, Leonard and Penny tease him about loving his friend, but Sheldon firmly denies it.
    Penny: Who are you kidding? You were so panicked Leonard was gonna die, you'll never leave him.
    Sheldon: I was not panicked, and I am not overly attached to Leonard.
    Leonard: You were so worried that you smashed your face trying to check on me: you love me!
  • There's also the episode where Sheldon runs away and leaves a farewell video addressed to "three friends and one acquaintance." The end of the episode reveals that the "acquaintance" is Howard.
  • Happens in Young Sheldon. When Paige comes over to spend the night with Missy, Georgie says that he thought Paige was Sheldon's friend. Sheldon says that he views Paige as more of a colleague. Georgie, hilariously, asks what the heck is a colleague.
• The Friend Nobody Likes: So much that the guys kick him off the team for the Physics Bowl in "The Bat Jar Conjecture". And when Sheldon wants to accept an offer to go on an arctic expedition, they are excited about being Sheldon-free for three months. Penny once asks exactly how he got any friends in the first place and Howard answers that they liked Leonard. Leonard even calls him out on this slightly saying Sheldon is the reason they don't do a lot of fun activities. In the episode where Leonard, Raj, and Howard are on a camping trip:
  Leonard: Too bad Sheldon couldn't come with us.
  Raj: Yeah, it's just not the same without him.
  [silence for a second and then the three guys start laughing]
• Geek: His life is almost exclusively devoted to the huge interests of science, science fiction, fantasy, comic books, and video games.
• Geek Physiques: He was described by another character as looking like a praying mantis. The other three geeks also have skinny physiques. It's just that Sheldon's is more pronounced due to being a head taller than the other three.
• Geeky Turn-On: For a long time his roommates thought he "had no deal", because his deal is extremely specific, namely it is Amy roleplaying his favorite fictional characters or discussing scientific facts related to an on-going conversation.
• Genius Burnout: Sheldon was on a fast track to become highly gifted in the scientific community, getting multiple doctorates before others are in high school. He has had some success in his field, but underling a lot of his concerns is that he wants to be exceptional even among geniuses and has aspirations to be a Nobel winner. In other episodes, including getting fired, dealing with a new teen genius one-upping him and having some of his theories disproven, it's surprisingly easy to see him spiral into depression.
• Good is Not Nice: A perfect example in that he's really a good and well-intentioned person, but he's so obnoxious, selfish, and condescending that he comes off as irritating. Just about everyone considers him a foolish manchild who either can't or refuses to become independent.
• Grade Skipper: It's been mentioned numerous times on the show that Sheldon was much younger than traditional-age when he went to high school and college.
• Green-Eyed Epiphany:
  • Season 5 shows that Sheldon has grown very possessive of Amy, if nothing else. When Leonard states that he and Amy had quite a fun time together at a wedding party and playfully threw in sexual innuendo about this "fun time", Sheldon's reaction? A karate chop to Leonard's neck and then:
    Leonard: Why did you do that?
    Sheldon: To send a message: she's not for you.
    Leonard: What?
    Sheldon: Not! For you!
  • Later when Amy begins to date Stuart, Sheldon "officially" upgrades the status of their relationship to boyfriend and girlfriend.
• The Grinch: Sheldon hates Christmas, claiming it's a knockoff of the pagan celebration of Saturnalia, bemoaning being forced to participate by his zealously religious mother as a child, etc., all to the annoyance of Leonard, who just wants some Christmas cheer because he was forced to write papers by his family on Christmas. It all comes to a head during a Christmas themed game of Dungeons & Dragons where Sheldon leaves Santa (whom they were supposed to be saving) to die, ruining the game and Christmas spirit for all involved. He declares that the real reason he hates Christmas is that Santa never granted him his wish of bringing his "Pop-Pop" (grandfather, and the only family member to encourage his interest in science) back as a kid.
• Happily Married: To Amy Farrah Fowler.
• Hard on Soft Science:
  • Exaggerated with him to the point of absurdity. Not only does he regard the social sciences as "largely hokum" (although despite this, he deeply respects Leonard's psychologist mother, however, she's also a neuroscientist), but he also speaks disparagingly of other hard sciences, referring to the geology department as "the dirt people" and having a falling out with Leslie Winkle because she favored supergravity theory over superstring theory. The only non-scientific discipline he has not expressed open contempt for is the law, probably due to his mania with rules.
    Sheldon: I have never said that you [Howard] are not good at what you do. It's just that what you do [Engineering] is not worth doing.
  • Despite his distaste for the "softer sciences", he does occasionally show at least a basic knowledge of philosophy and linguistics, such as explaining to Penny what "semiotics" is. That's because, as revealed in Young Sheldon, he actually took philosophy classes while he was studying at university (and the one we see him taking focuses precisely on semiotics).
• Hates Being Touched: He's terribly awkward about getting close to people, sometimes due to his germophobia and sometimes because he's so bad at showing emotions. In later seasons, he gets a bit better.
  Sheldon: It's not a touch phobia, it's a germ phobia. If you'd like to go put on a pair of latex gloves, I'll let you check me for a hernia.
• He Cleans Up Nicely:
  • When he has to give a speech, Penny takes him out to buy a new outfit. Sheldon emerges from the changing room looking stylish, dapper and let's face it, handsome, in a black suit. Penny can see how much a decent suit changes his gangly appearance. Sheldon finds the outfit absurd - his usual suit is a garish checked number.
  • In Season 6, when Penny gives him a new haircut, Amy is shocked when she sees it and insists that Penny change him back — because she's worried he might attract other women. "I don't want him walking around like sex on a stick!" (Sheldon agrees. "She's right. I'm too hot.")
• Henpecked Husband: After a fight with Amy, he has decided to be one to avoid major fights in the future. So when Amy tells Levar Burton he's a worse actor than Wil Wheaton, Sheldon tells the former while he may not actually think so, he must agree with Amy. Levar understands completely. This does not normally occur, as he is mostly the dominant one in their relationship.
• Heroic Sacrifice: Not a lethal one, but during a paintball war his comrades (Leonard, Howard, and Raj) lack the enthusiasm due to prior events, and don't really want to fight. Sheldon decides to walk outside, into the open, claim that geology isn’t real science, and take several shots to motivate them into fighting, resulting in victory. Complete with slow-motion and a Platoon-style "death".
• Hidden Depths:
  • Sheldon proves to be surprisingly understanding and helpful when hearing about his friends' love problems. He also knows a lot about football, though it's only because his father always made him watch the games as a child, rather than out of his own interest; plus he grew up in Texas, where he mentions that football is inescapable there. Also thanks to his father he is apparently a crack shot with both a bow and a gun. Due to his upbringing, he is also a skilled ballroom dancer and archer. At times, he seems to know more than the other guys about proper social interaction, but he is that selfish and he's very poor at applying it to real-life situations.
  • Despite his irreligious views Sheldon is astonishingly knowledgeable about Hinduism, at times bringing up aspects of it that even Raj is unaware of.
• Hilariously Abusive Childhood:
  • Sheldon is revealed to have been so traumatized by his parents' constant fighting when he was a child that he is unable to be around people arguing. He goes so far as to run away from his apartment when roommate Leonard won't stop arguing with his girlfriend. He relates multiple incidents of being bullied (sometimes by his own siblings) that fit the trope, such as discovering string theory, due to being beaten round the head with a book about it.
  • However Young Sheldon reveals that this isn't exactly true, as while his parents had some marital problems which would explain his issues when hearing others fight, his childhood wasn't nearly as horrible as he made it sound. In fact it's implied that due to his arrogance and narcissism, he simply has a very Self-Serving Memory where he exaggerates the bad things that happened to him while downplaying or ignoring the suffering his family went through and the problems he caused.
• Hollywood Atheist: Sheldon is an atheist, and in his prequel series Young Sheldon he was very vocal about it because his mother and Pastor Jeff kept trying to convert him to Christianity but he resisted. Given that Young Sheldon occurs from 1989 into the early nineties, being an atheist was a rarity back then in the United States and atheists faced greater pressure to convert to local religions at the time. This is further compounded by the fact that Sheldon grew up in Texas, which is a Bible-belt state.
• Hollywood Autism: He's not officially diagnosed as Autistic but he's likely somewhere on the spectrum. Sheldon is a savant with science, literal-minded, possesses child-like qualities, and is socially awkward. Prior to meeting Leonard and Penny, Sheldon was socially impaired until he matured and eventually married Amy.
• Honor Before Reason: Will often avoid taking the easy way out of things, though this usually leaves him worse off than before.
• Humanity Is Infectious: As much as Sheldon doesn't want to admit it. He has been greatly influenced by the people in life because at first Sheldon was very anti-social with people, inconsiderate and had no desire for intimacy. Sheldon's morals were built by his mother and his friends, his relationship with Amy grew intimate and he learned to be considerate with his friends. Granted, he still has moments of sarcasm and bitterness, but he has improved greatly when he's compared to how he started out in the series.
• Hypochondria: Sheldon is terrified of diseases and prone to overprotecting himself. In one episode, he gets a stomach ache from eating too many Brussel sprouts and thinks it's cholera.
  Leonard: There's no cholera in Pasadena. Just like last summer, when there was no malaria in Pasadena.
• Hypocrite:
  • Calls Priya a know-it-all for explaining the origins of the "toast". This is in spite of in 90% of his conversations, he brings up such topics at any given chance.
  • Often makes fun of Penny for being born in Nebraska while he himself is from East Texas.
  • Sheldon loves rules and believes they are the foundation of society, but he only ever enforces rules that benefit him and will try to avoid or get around any that don't work for him. Also, if he believes the world has descended into chaos, the very thing he believes rules help avoid, he will openly ignore any rules, like his Mother telling him to sit back down in class or even his own Roommate Agreement. Season 3's "Excelsior" proves that Sheldon has contempt for the Californian legal system and unnecessarily insulted a judge simply because he was given a traffic violation ticket (which he overreacted about).
  • Often accuses Leonard of being a narcissist and wanting to make everything about him, without a hint of irony.
  • Is an opportunistic show-off concerning intellect, but in "The Jerusalem Duality" when Dennis arrived, Sheldon does not take well to being replaced by a 15-year old North Korean teenager as the smartest scientist in CalTech. If Sheldon were to follow his own words he would have bowed to Dennis and not shooed him to go away.
  • Hates all forms of change big and small and constantly tries to keep his life as consistent as possible. However, as Leonard points out in "The Table Polorization", the spot on the couch that Sheldon loves so much was itself a change due to Leonard buying the couch in the first place, and Sheldon is unable to explain why that was a good change and all others are automatically bad.
  • Sheldon is a major germaphobe and does everything in his power to avoid getting sick, which includes refusing to visit hospitals to support his friends and staying as far away from anyone he knows is sick to avoid getting infected. However, when he actually does get sick himself, he expects for everyone to cater to his every demand, and help him get better when he dismisses their own sickness as "not his problem".
• Iconic Attribute Adoption Moment: He spent the first five seasons of Young Sheldon wearing button down shirts with a bowtie. The season five finale "A Clogged Pore A Little Spanish And The Future" ended with him embracing adolescence by donning a Flash T-shirt on top of a long sleeve shirt, much like the outfits he would wear as an adult in The Big Bang Theory.
• Ignorant of Their Own Ignorance: While Sheldon is undeniably skilled in the field of theoretical physics, the moment he steps out of his narrow range of expertise he becomes woefully inept at any subject he approaches. Nobody seems to have told him that though, as he is utterly convinced that he as just as brilliant and informed on any other subject under the faulty logic that because he's an expert in theoretical physics, and because everything else is an application of theoretical physics, that he must be an expert in everything.
• Informed Ability: Although the other scientists do have some level of respect for his abilities (Leonard at one point calling him "one of the greatest minds of the 21st century"), Sheldon is by far the most fervent admirer of his own intellect, but he frequently makes mistakes (especially in non-scientific fields, sometimes even then) and besides being given an award by the University all his accomplishments are second-hand information. Lampshaded by President Siebert, "The board tells me he has a beautiful mind, but I just think he's bananas."
• Innocent Bigot: Occasionally says things that may be considered offensive without realization.
• Innocent Blue Eyes: He has large, expressive blue eyes. They may or may not be a physical manifestation of how clueless he is about social interaction, despite his intellectual brilliance.
• Innocently Insensitive: Even when he's trying not to be an Insufferable Genius (usually at the request of one of the other guys), he has a problem of insulting people anyways without realizing it. It's debatable whether or not he realizes how insufferable he really is. Much of his innocent insensitivity stems less from his arrogance and overbearing manner than his total ignorance of social conventions. For example, in one conversation with Penny, he asks her where she currently is on her menstrual cycle. He doesn't understand why it's inappropriate.
• Innocent Prodigy: In Young Sheldon. He's more naive and innocent than both his siblings, despite being much smarter than them. In one episode, it's revealed that he knows how the human reproduction works only because it was his twin sister who told him. Of course, as an adult, he will grow up into a full-on Ditzy Genius.
• Insane Troll Logic: Sheldon's thought processes are very alien, and he occasionally purposefully distorts logic to get his way.
  • If he cannot have his way or if he manages to fail at an activity then he will often dig deep to find some way to justify why he didn't succeed. After failing at learning how to drive he decided he was an evolved form of humanity that was smarter but incapable of driving properly.
  • In Season 4, he and Amy play a game called "Counter-Factuals", where they offer a For Want Of A Nail scenario where the world is different in some manner, and figure out what the answer to a question is. In this game, Sheldon rationalizes that if a giant beaver ruled the world, it would lead to a chain of events that results in the cheese danish never being invented due to worldwide flooding.
  • By the rules of the Roommate Agreement, if he and Leonard vote on something and it's a tie, he settles the tie. Leonard reminds that he voted against this, to which Sheldon counters he voted "yes", and he settles all ties, so it was a yes.
  • Subverted in some other ways. Though some of his lifestyle choices are strange to outsiders, he has well-thought-out reasons for them that make sense, if in a obsessively compulsive way. For example, his spot on the couch comes with a list of reasons why it is his spot, from balanced airflow in the room to allowing maximum interaction with guests (with minimal head-turning) while still allowing a proper view of the TV without distorting the image.
• In-Series Nickname:
  • His mother and sister call him "Shelly", though he does not seem to like the nickname. Leonard and Penny have occasionally used the same term. His grandmother calls him "Moonpie", because he is so sweet to her. When Penny uses the nickname, however, Sheldon replies: "No one calls me Moonpie but Meemaw".
  • In "The Isolation Permutation", a drunk Amy nicknames him "cuddles".
• Insistent Terminology: He is not a rocket scientist. He's a theoretical physicist! Also, he takes great pains to point out that his team t-shirt spells "The Wesley Crushers" (Those Who Crush Wesley) and not "The Wesley Crushers" (Multiple People Named Wesley Crusher). Dr. Sheldon Cooper would also have you know that he's not crazy; his mother had him tested. She later confirms this (... though she should have followed-up with that specialist in Houston). He also does not play "pranks"; he subjects people to his classic pranks. He also prefers it when accurate terms are used. One of the more notable things he prefers is to refer to sexual intercourse as 'coitus', probably to separate it from sex as in 'male or female'..
• Insufferable Genius: He's that page's image for a very good reason. Though it's been shown repeatedly that it isn't impossible to outsmart him or even point out mistakes in his work, it's a matter of being stubborn enough to fight him through the insufferable part (Stephen Hawking notwithstanding). He was even more insufferable as a 9 years old kid.
• It's All About Me: Though he is able to show concern and attention for his friends on occasion, Sheldon's default attitude is wildly egocentric, taking the view of "the world revolves around me" as an axiom.
  Penny: I'm sorry Sheldon, but this really isn't about you.
  Sheldon: [pause] I don't follow you.
• Jerkass Has a Point: There are a few times where despite being a condescending jerk, Sheldon does make some good points.
  • Sheldon spent years telling Penny to pay attention to her check engine light on her dashboard (even though her car wasn't built with one). While Sheldon is annoying and rude, he did have a point that Penny should pay more attention to her car, especially when it finally breaks down for good.
  • In "The Apology Insufficiency", Sheldon intentionally tried to ruin Howard’s chance to work on something he really wanted to work using a series of petty reasons that no one but him cared about, only to accidentally let slip that Howard got the Mars Rover stuck in a ditch. While this is an highly jerkass thing to do, especially given his reaction in "The Electric Can Opener Fluctuation", it doesn’t change the fact that Howard let a random girl into a secure area to pilot the Mars Rover, which eventually ended with her crashing it in a ditch, all in a vain attempt to get laid, then destroyed the evidence of it to cover his own ass. Even if it was something Howard really, really wanted to do, it still doesn't change the fact that he really, really didn't deserve the clearance because of that.
  • In the episode "The Excelsior Acquisition", Sheldon is fined for driving without a license and running a red light to get Penny to the hospital for her fractured arm from the episode "The Adhesive Duck Deficiency". While Sheldon stubbornly refuses to accept he was guilty of the crime and pay the fine, he was right to be angry at Penny, because the ordeal was her own fault for denying responsibility for the ticket on her car and throwing him under the bus so she herself wouldn't get into trouble.
  • In "The Lunar Excitation", when Zack question how the guys know their laser project won't blow up the moon, Leonard states that is an excellent question to which Sheldon quickly points out that it is not. Penny then tells Sheldon to play nice, but Sheldon states that it is not and proceeds to ask why someone would possibly think that they are going to blow up the moon, stating that that is an excellent question. Jerk though he may be, Sheldon was well within he rights to chastise Zack for asking such a stupid and ridiculous question.
  • As much of an Insufferable Genius as he can be Sheldon often demonstrates that, in terms of scientific knowledge, he is as smart as he thinks he is.
• Jerkass to One: A "Crueler to One" example. Sheldon is an insufferable know-it-all who likes to belittle people for not being as intelligent as him. Howard gets the worst of it due to him possessing a Master's Degree (Sheldon once referred to it as a "trade school diploma") instead of a PhD like Sheldon, Raj and Leonard. Even Penny, who has no college degree at all, doesn't have her intelligence insulted by Sheldon as frequently as Howard does.
• Jerk with a Heart of Gold:
  • He's insufferable most of the time, but he shows concern and attention for his friends in his own ways, can offer genuinely helpful advice on their problems if he's in the right mood, he's never actively malevolent to them beyond verbal jabs, and is hurt if they slight him in some way. On the other hand, his perspective on social interactions are skewed, so he doesn't understand when he does something offensive or inappropriate, he's constantly flaunting what he considers his superior intellect, and while he can offer helpful advice on a problem at times, he's just as liable to interrupt their explanation of said problem to note he doesn't care. The Heart Of Gold is there, but it's deep down under a lot of arrogance and neuroatypicality.
  • In the flashback where he and Leonard met, he first forces the latter through rigorous tests to determine if he's allowed to move in, and later ruins his relationship with a North Korean exchange student. At the end of the episode, he saves Leonard's life, and doesn't even make an issue of it (also, the exchange student turned out to be a spy, although he might not have known that beforehand).
  • Throughout the series, he will always maintain this trope-sometimes, the focus is more on the "Jerk" part, and sometimes more the "Heart of Gold" part.
• Jock Dad, Nerd Son: He often talked about how his father forced him to learn football. In Young Sheldon his father is revealed to be a football coach.

K-O

• Karma Houdini: Rarely does he receive more than a slap on the wrist for all the crap he puts his friends through. In many cases, when it seems like things have come to a head and one of the other guys has finally had enough of his antics, a Deus ex Machina will ensure that Sheldon escapes punishment and his obnoxious behavior is vindicated.
• Karma Houdini Warranty: Eventually, his actions in his relationship with Amy catch up to him and it crashes and burns.
• Kick the Dog: He often mocks Leonard for his short height, his poor vision requiring glasses, his asthma, his lactose intolerance and for not graduating from high school at age 14. Leonard's physical disadvantages just make Sheldon feel all the more superior to Leonard.
• Kind Hearted Cat Lover: When he and Amy disagree over the superiority of physics vis-a-vis neurobiology, they terminate their friendship.^note Sheldon's mother manages to bring them back together in the end, thanks to a little judicious reverse psychology. He fills the void left by her absence by adopting a plethora of cats. His mother also sings him his sick song, "Soft Kitty" whenever he's sick, and so does Penny. Sheldon even sings it to her at one point.
• Know-Nothing Know-It-All: Sheldon tends to lapse into this when he veers away from physics and into the life sciences. Sheldon acts like he knows United States history when he doesn't. He tries to convince Leonard that he should be a history professor instead of a physicist by testing whether Leonard knows that slavery in the United States ended in 1863. It didn't. At the Renaissance Fair, when he complains about the historical inaccuracies, but doesn't realize Leonard's knight costume is at least 200 years out of date. His "defense" to a charge of running a red light in "The Excelsior Acquisition" shows he knows absolutely nothing about the law, as well. On similar lines, his beloved Roommate Agreement is full of loopholes, and doesn't stand up to the scrutiny of a legal professional. Many of his beloved factoids, when outside the sciences, are actually common misconceptions: The Romans did not sow over Carthage with salt, for instance, as any archaeology undergrad could have told him. Even worse, sometimes he fails at science. For example, when Amy is sick, and Sheldon wants to help her, he asks if she believes in the placebo effect, then shows the placebo - but the placebo effect only works if you believe the placebo actually is medicine. However, this is often a case of Depending on the Writer, as sometimes he is presented as being as smart as he thinks he is (or at least knowledgeable in a broad range of areas). The Rule (following the Rule of Funny) often seems to be that he only slips into this whenever it would actually benefit him not to.
• Lack of Empathy: Subverted. Although he often comes across as this, Sheldon is perfectly capable of feeling empathy and can even be quite caring on occasion. It's just that he's very bad at showing it.
• Large Ham: He can be quite overdramatic.
• Lean and Mean: Lanky and incredibly insufferable and obnoxious. He does have a good side deep down but his jerkishness is more emphasized.
• Like Brother and Sister: With Penny. In the episode "The Intimacy Acceleration" they conduct an experiment designed to make people fall in love by asking each other a few personal questions. They don't fall in love but reflect more about their friendship and they both admit that they look on each other like a brother and a sister.
• Like Parent, Like Spouse: Like Grandparent, Like Spouse is more appropriate, but his wife Amy is very much like his Meemaw. Dowdy clothes, glasses, and married to a narcissist.
• Limited Wardrobe: Almost always wears short-sleeved t-shirts with a longer shirt underneath, rolled up to the elbows. Superhero t-shirts are the most common, Green Lantern (or a symbol of one of the other Lantern Corps) and The Flash especially. This leads to a rather amusing variation of Characterization Marches On, as in one early episode he follows the general pattern, but it's far removed from what he was later known for.^note Interestingly enough, the color combination is that of classic Silver Age Lex Luthor's power armor, meaning that, perhaps they went for the "evil genius" look.
• Literal-Minded: More than everyone else, being Sarcasm-Blind.
• Little Known Facts: Loves bringing them up in conversation, sometimes to benefit himself such as why he should have the last dumpling, because in Tia culture its reserved for the most valued member of the group.
• Mad Scientist: Has about as many shades as you can get while still being thoroughly grounded in reality. A brief list of examples is his willingness to try electric shocks to modify Penny's behavior by negative reinforcement, the government monitors his computer activities due to his efforts to hack their systems, as a child he attempted to build a "death ray" and to create a griffon by cross-breeding lions and eagles, and he occasionally makes references to societal reforms he plans to implement when "[he] comes to power". Lampshaded by Leonard, who notes Sheldon is "one lab accident away from becoming a supervillain."
• Manchild: While all the characters indulge themselves in silly stuff, Sheldon insists that someone take care of him the way his mother would when he's sick (or even just homesick), locks himself in his bedroom where no one else is allowed whenever he's furious, runs away from home when he's upset, is practically traumatized by the sound of people arguing^note Although this one may be perfectly justified, as his parents often got into arguments when he was a child and it is also implied that a lot of the arguments were exceedingly violent (he mentioned that his father would start throwing plates and shattering them in the kitchen, and that his mom planned to place glass shards in his father's meatloaf), even when they said to Sheldon that they quit fighting, and is stubborn and petty beyond all reason. The only thing on this planet that can force him to behave rationally when he's angry or depressed is an order from his mother, whom Leonard calls "Sheldon's Kryptonite". He also responds positively to being patronized by Penny, especially if he gets a toy robot and a comic book out of it. Lampshaded by Bernadette at one point, after she successfully got him to go to bed by first reasoning with him about the effects of lack of sleep, and then simply treating him like an overgrown child and sending him to bed.
• Manipulative Bastard: Although failing on most of his attempts in the first few seasons, starting Season 6 and appearing more commonly in Season 7, Sheldon begins to get more successful at his attempts to manipulate others, learning how to play off of their weaknesses to his advantage.
• Meaningful Name: Named for television producer Sheldon Leonard and possibly for physics Nobel Laureate Leon N. Cooper.
• Minor Injury Overreaction: His response to getting a cut on his thumb? He faints.
• Momma's Boy: His mother still treats him like a child and is the only person who can tell him what to do.
• Mother Nature, Father Science: A rather blatant example with Amy, who's a biologist and him a physicist.
• Mouthy Kid: From time to time when he was a child, most notably in "An Entrepneuralist and a Swat On The Bottom.'
• Narcissist: The most fervent admirer of his own genius.
• Neat Freak: He broke into Penny's apartment to clean, because being that close to mess made him have trouble sleeping.
• Never My Fault: He always tries to avoid any blame for anything that happens to him or his friends. If he failed something or did something wrong then he will state that he is so smart the thing he failed at isn't important enough to learn. Whenever he is an inconvenience for someone then it is their own fault for being too dumb to understand his genius advice or not being able to control their own anger. Many of his own problems have a very simple solution to them and he would avoid angering a lot of people if he would simply apologize, but instead he often thinks of overly complex solutions to avoid the simple solution because doing so would either damage his pride or would cause a very minor inconvenience that only he cares about. If he does apologize to someone it will usually be a Backhanded Apology so he can have the last word or avoid taking all the blame. Which makes those rare occasions (see Pet the Dog below) when he does admit his own fault even more significant, such as when he accidentally cost Howard his security clearance, leading to his career suffering a serious setback.
• No Sense of Humor: Zigzagged. Sheldon has a sense of humor, but it's so separate from everybody else (except for Amy) that he doesn't get most jokes and most people don't get his. And he always explains his jokes.
• No Social Skills: To the point where Sheldon seems to consider "accepted social protocol" more like inviolable laws he must obey, rather than doing nice things simply because he's trying to be pleasant. Lampshaded a few times by Penny.
  Sheldon: Social protocol does, however, require me to bring you a hot beverage in your time of need.
  Raj: No, thank you. I'm fine.
  Sheldon: It's not optional.

  Bernadette: Well, what does your cotillion training say is expected of a gentleman when three ladies ask him to escort them to a dance soiree?
  Sheldon: I saved a nun’s life. Why am I being punished?
• Not-So-Harmless Villain: Although rarely a true villain, whenever he does take an antagonistic role, it's normally either as a petty prankster seeking revenge or an egomaniac Control Freak whining to others when he doesn't get his way. However, in "The Itchy Brain Simulation", he proves he when he's had time to plan he can be quite impressive. He successfully manipulates his own best friend into simulating OCD, and torturing himself, all while barely lifting a finger. He is certainly smart enough to plan some extremely potent revenge schemes but he tends to fail or go sideways in execution (a prank against Kripke involving a fast expanding foam ended up being sprung when members of the board are visiting his office).
• Now Allowed to Hug: Sheldon dislikes hugging people, though as he notes to President Seibert in one episode, it's not a touch phobia, it's a germ phobia. However, there are two occasions where he hugs people.
  • In one Christmas Episode, Sheldon has gotten a large number of gift baskets for Penny in order to prepare for whatever gift she gives him. His plan is to give her the gift basket equivalent to the gift she gives him, then returns the rest. When she reveals that her gift is a napkin signed by Leonard Nimoy, he gives her all of the gift baskets, and declares it's not enough. He then offers her a sincere and heartfelt hug.
  • In another episode, Sheldon guilts Penny into giving up her place on a trip with Leonard to Switzerland to see the Large Hadron Collider. Sheldon gives her a hug. This actually causes him to miss out on the trip, because Penny was already carrying a flu bug, and Sheldon caught it from her. Sheldon and Penny are stuck together on Valentine's Day, while Leonard ended up having to take Raj to Switzerland.
• Odd Friendship: A brief one with George Jr.'s bully Tommy Clarkson in Young Sheldon episode "David, Goliath, and a Yoo-Hoo from the Back". They bond together because Tommy can control George Jr. But it looks like now it's not going any further, implying that Sheldon could've been punished for what he did.
  • With Mike Rostenkowski (Bernie's dad), of all people. The two of them bond during Thanksgiving over Sheldon's knowledge of football.
• Ooh, Me Accent's Slipping: There's only a slight hint of Sheldon's Texan accent when he normally speaks, but he does slip into it more when he's with his mother and goes full-on Texas when he's drunk.
• O.O.C. Is Serious Business: The few times he deviates from specific idiosyncrasies is treated as exceptionally odd and results in some big reactions from the characters, notably how Penny started crying when Sheldon gave her a hug for the Leonard Nimoy Napkin Christmas gift.
  Leonard: Between Sheldon giving up his spot on the couch and you (Penny) playing chess like Bobby Fischer, I would guess that someone went back in time and stepped on a bug, changing the course of human events.
• Omnidisciplinary Scientist: To a ludicrous extent in the first few series, (built a complete, functioning CT scanner up to the imaging software when he was eleven, discovered a new phase of matter but didn't even bother to present his findings and genetically engineered a bioluminescent fish, working from home, in a matter of weeks) toned down later on but still present.
• Only Friend: To Tam Nguyen, in his childhood (Except for that brief time when Libby was also their friend, as well as his brief and one-time Odd Friendship with George Jr.'s bully Tommy Clarkson).
• Out-of-Character Moment: His obsession with cleanliness was evident early on, with him cleaning Penny's apartment himself while she slept and later panicking when he hears she came from a family gathering where they were sick. In the Season 1 episode "The Loobenfeld Decay", he places a bag of chicken in a take-out container into an outside bin, then recovers it a few minutes later with nothing more than a quick blow. It certainly stands out as an anomaly with his regular behavior.
• Out of Focus: Despite his name being in the title, Young Sheldon focuses on Sheldon less and less as it goes on. From season 5 onward, Sheldon is often relegated to the B-plot while his family members are usually the focus of the A-plot.
• Overcomplicated Menu Order: He expects all his food to be severed to him in an incredibly specific way. This often includes him going through a list of things he wants with his food upon it being delivered to him to make sure it is exactly the way he likes it, and will be disappointed if even the slightest thing is not right. This and his usual annoying personality and ungratefulness make him a nightmare for waitresses, with Penny implying that she would occasionally spit in his food for his rudeness and the implications in the penultimate episode that other waitresses do it as well.

P-T

• Pet the Dog: He's typically very selfish and insufferable and frequently comments on how much he hates social interaction even with his closest friends. But there are a few rare moments where he actually uses his selfish behavior as a smokescreen to hide that he's actually concerned and/or happy for his friends, but doesn't want to admit that right out. For instance, he discovered through Amy that Penny had some doubts about her relationship with Leonard. So he confronts her late at night and tries talking Leonard up, saying that he just wants to keep the status quo for his own sake. As the conversation went on, he eventually asked with sincerity, "Please don't hurt my friend."
  • When Mrs. Wolowitz suddenly dies in her sleep during Season 8, Sheldon tries to speak to Howard. Leonard, righteously worried that Sheldon will say something inappropriate, tries to stop him, but Howard lets him talk. He says the most heartfelt thing he has ever said in-series:
    Sheldon: When I lost my own father I didn't have any friends to help me through it. You do.
    Penny: [sobbing] I really thought he was going to say “Let it go”.
  • One of the earliest is when Penny has a string of financial problems. Without a moment's hesitation, Sheldon reveals his secret cache of emergency funds, implied to be a few thousand dollars, and tells her to take what she needs and pay him back whenever she's able. And he means that last part; he trusts that she'll pay him back eventually, so he doesn't worry about when.
  • Happens more frequently in Young Sheldon.
    • In "A Crisis of Faith and Octopus Aliens", Sheldon consoles his mother when she stops going to church and saying grace before dinner, helping her regain her faith by saying that while he doesn't believe in the Christian God, he does believe that the Universe has a creator. How else would he have such a wonderful mother? And it works.
    • Done again in "Body Glitter and a Mall Safety Kit". Paige has stopped applying herself in school and has started dressing and acting like a delinquent even placing stolen body glitter in Sheldon's backpack to avoid detection. Even though Sheldon dislikes Paige and is upset that she framed him, he knows something is wrong. After calling Dr. Sturgis for advice, Sheldon willingly listens to Paige talk about her problems at home, even offering her a hot beverage after the fact (his go-to in comforting people in The Big Bang Theory).
• Photographic Memory: He has it, though he objects to the name and insists that it's properly called eidetic memory. He certainly has hyperthymesia, as he can recall details about his lived experience like what he ate on any given date and whether someone complained that their chicken was dry, but he's never actually shown to have a photographic memory of things he reads or watches, although he has been shown to read complex materials frightfully fast.
• Polar Opposite Twins: With Missy. Sheldon is wildly egocentric, only interacts with others when forced to and tends to look down on anyone who isn't as smart as he perceives himself to be. Missy is out-going, friendly, level-headed and sociable. Sheldon points out that non-identical twins will only resemble each other as much as siblings born on separate occasions.
• Precocious Crush: Might have had one on a girl named Libby in Young Sheldon. At the time he was a nine-year-old in high school, so she's several years older than him. He doesn't object when his family refers to Libby as his "girlfriend", the two spent hours talking on the phone, were toying with sharing activities together outside of Geology, and the most damning piece of evidence being how he reacts to Libby telling Mary that she was "babysitting" Sheldon. He breaks down in tears and swears eternal hatred over Geology due to this. However he could have also simply became friends with her and was hurt that she didn't see him as an equal.
• Proud to Be a Geek: Sheldon simply refuses to be anything but a geek and unlike his friends (mostly Leonard) he isn't embarrassed at all by his geekiness.
• Rail Enthusiast: A fan of model railways, he even wears his own pretend-Engineer's hat. This would be rather sweet if he didn't neglect Amy for it, something which visibly offended her.
• Renaissance Man: One episode of Young Sheldon reveals that he has an impressive talent for acting, singing, and tap-dancing besides, of course, being an academic genius (and later becoming an Omnidisciplinary Scientist). He immediately gets the lead role in a play... but he can't perform because he has stage fright.
• The Reveal: Young Sheldon episode "A Stunted Childhood and a Can of Fancy Mixed Nuts" reveals the origin of Sheldon's "Bazinga" catchphrase on Big Bang. In an attempt to loosen himself up and be more carefree like Missy and Paige, he buys a set of practical tricks from the comic shop, manufactured by Bazinga Novelties; Sheldon takes the tagline "If it's funny, it's a Bazinga" quite literally.
• Rule of Three:
  • His characteristic knock on the door is a Running Gag. Three knocks, followed by calling the name or names of whoever is on the other side of the door (Penny, Amy, Bernadette, etc.). Followed by a second set of three knocks and another call of the name/s. And finishing with a third set of three knocks and another call of the name/s. When the door opens before Sheldon has a chance to complete his ritual, he simply continues knocking the open door.
  • There a few minor deviations of the general rule. In "The Toast Derivation", Sheldon does not call Leonard, Howard, and Raj by their names, using the phrase "all my friends" three times. In "The Anxiety Optimization", Sheldon does not call Penny, Amy, and Bernadette by their names, using the word "ladies" three times. Played for Laughs in "The Opening Night Excitation" as (1) he has to match the name with whoever asks him to come in, and (2) he calls Amy "Birthday Girl".
• Rules Lawyer: Provided they're either rules he drafted himself or those governing the playing of Tabletop Games. As Priya and "The Excelsior Acquisition" showed, he doesn't have a very good handle on the actual law. Though it is likely his arrogance plays a part in this. He was able to match her on his second try.
• Sacrificed Basic Skill for Awesome Training: Sheldon is such a Child Prodigy that he entered college at age eleven and graduated with honors at fourteen. He has devoted pretty much his entire life to research since then, and this may have contributed to his lack of rudimentary social skills (such as not gloating at a judge) and his overall inability to deal with the mundane world (germophobia for instance).
  Leonard: Sheldon's in jail?! For what?
  Penny: For doing the same crap he always does, except to a judge.
• Safety in Indifference: Tries to insist that he's fine with Amy's decision to end their relationship. It cracks when he has an anger outburst when Penny points out that he's capable of emotion like everyone else and concedes that he's not moved on yet.
• Sarcasm-Blind: Zig-Zagged. He understands the concept of sarcasm and can use it himself, but almost never picks it up when it's about him. He gets lucky once in a while, but it seems like guesswork on his part. Leonard even made a sarcasm sign in an early episode. And Sheldon keeps track of how many times he correctly understands sarcasm. Once, when Howard made a sarcastic comment, Sheldon asked "Was that sarcasm?", and Howard sarcastically replied "No!" — which, of course, Sheldon failed to recognize the sarcasm of. In at least one episode, this is inverted: Sheldon takes something as sarcastic when it isn't. There was one episode where after being kicked off the group's app team due to his unbearable attitude and staying with Penny, she eventually convinces everyone to take him back if he apologizes. Sheldon doesn't want to apologize so Penny tricks him into "apologizing sarcastically" as practice for his sarcasm. Sheldon thinks he did a good job when really he was just lying to everyone.
• Selective Obliviousness: Selective is an Understatement. Sheldon will almost NEVER see his own faults, mistakes, or flaws as his own fault. On the other hand, he will hypocritically point out the, in his own arrogant and often wrong opinion, numerous faults and mistakes in others. He will often use pop culture references to prove a point only to completely disregard them as irrelevant when he's called out as wrong. He will also never apologize or help someone if he can help it but expects others to bend over backward to please him. Pathetic wimps like Leonard actually encourage this behavior due to low self-esteem.
• Self-Serving Memory: His obliviousness to his own faults and Lack of Empathy mean he tends to rewrite his own recollection of events with his opinion of those involved, while Young Sheldon shows how things actually happened. For instance, despite Sheldon's stories, his father was a kind and supportive man who made one mistake, and that mistake warped Sheldon's opinion of his father to only focusing on perhaps the few minor mistakes he made in his life. He describes Billy Sparks as a bully, even though (outside of the pilot episode) Billy was always nice to Sheldon while Billy's younger sister Bobbi was the one who actually bullied him. Also because of Tam unintentionally hurting Sheldon, he leaves him out of every story he tells about his childhood in Texas. This extends to his family as due to his great relationship with his grandmother he ignores the many flaws she had during the prequel, while with Georgie and Missy he can be cruel in how he talks about them and all the times they "bullied" him growing up (one episode showed Sheldon befriending one of Georgie's bullies and using him to get what he wanted, and most of Missy's worst behaviour towards him was caused by how horrible he was to her).
• Sesquipedalian Loquaciousness: Uses lots of big words, even when it's not necessary.
  Sheldon: 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.
• She's Not My Girlfriend: Amy. In his own words: "She's a girl and she's my friend, but there's no touching or unsanitary exchange of saliva." Finally subverted in Season 5, where while Sheldon holds to the ban of physical intimacy, he and Amy are "officially" together, as noted by the Relationship Agreement he drew up. As of Season 7, occasional kissing seems to have entered their relationship. Presumably, the exchange of saliva is highly sanitary. As of "Opening Night Excitation", coitus seems to have entered their relationship.
• Sibling Yin-Yang: Missy and him couldn't be more different despite being fraternal twins.
• Signature Laugh: A sort of quick inhalation sort of thing.
• Silence, You Fool!: Expect Leonard to get shut down by him if his love-life interferes with their order waiting times at bars or restaurants.
• Single-Target Sexuality:
  • Amy is the ONLY person he has ever expressed romantic (and later sexual) feelings towards. While other women (and men) have shown some form of attraction to him, the most he ever reciprocates is an appreciation that they appreciate him. For the most part, he seems entirely oblivious to people who display attraction to him and openly expresses his total lack of interest in romantic/sexual relationships. The only exception to this is Amy when he ends up developing unexpected feelings for her and asks her out. Even though a sexual relationship is still repulsive to him and the first several years of their relationship are non-sexual, he confessed to Amy that what the two of them have is the most intimate relationship he has ever had. Later, when Penny asks if there's a possibility for sex in his relationship with Amy, he says yes. This completely floors Penny. When his colleague Ramona ends up kissing him while Amy is away on a work trip, he realizes the only person he experiences intimate feelings for is Amy and she is the only match for him. He also explains that the experience of being kissed by another woman told him that "Amy is the only woman [he] ever wanted to kiss for the rest of [his] life". As of "The Opening Night Excitation", he decides to start a sexual relationship with Amy in order to finally show how much he truly loves her. He admits to enjoying the experience more than he thought he would and, afterward, has no problem having sex with Amy whatsoever.
  • Young Sheldon had an episode where it's suggested that he might have a crush on his rival Paige, another Child Prodigy, and after answering some questions in Missy's magazine starts to consider it a possibility. Paige then tricks him into thinking that she also has a crush on him and that they should kiss, and she then drew a moustache on him while his eyes are closed. While it's implied that he was simply jealous of her and he expresses relief that he didn't feel anything romantic when they "kissed", this moment shows that when Sheldon was younger he wasn't completely opposed to the possibility of romantic feelings as he would be in TBBT. An earlier episode also implied that he had a Precocious Crush on an older girl named Libby, though it's ambiguous whether that's accurate or he really enjoyed her company.
• Small Name, Big Ego:
  • Played With, as in "Know-Nothing Know-It-All". He believes himself to be multi-talented when his only real skill is in theoretical physics but this does fall into Depending on the Writer as he sometimes genuinely is near to as smart as he believes he is and has shown in-depth knowledge of other subjects and his friends do on occasion acknowledge that he really is the smartest of them. He's also very unaware of how much people dislike him and can't understand why they wouldn't want to spend time with him. But of his friends he is the most successful (being the Senior Theoretical Physicist at Caltech) and is apparently held in high regard by the physics community. Never the less its made very clear that he doesn't live up to his opinion of himself.
  • This big ego was present even as a child. He thought that merely offering a correction to Dr. Sturgis' paper meant that he'd be credited as a co-author.^note  While Sheldon did correct a massive error on John's part, it still wasn't enough of a contribution to warrant a co-author credit.John did give special thanks in a footnote, but that wasn't good enough for Sheldon, who went as far as to accuse John of plagiarism, which nearly destroyed their friendship.
• Smart People Play Chess: He and Leonard play three-dimensional chess (yes, it does exist). He also created 3-man chess, complete with new pieces. Unlike many of his socializing-related projects, his new rules are seemingly enjoyable and not over-complicated.
• Smug Snake: Very smug about his genius-level intelligence. He sometimes talks about himself as a new and improved human. Ironically he can often live up to his claims, it's purely down to his ego that he fails. Indeed, many of the problems he encounters could be avoided if he wasn't so arrogant. A good example is "The Excelsior Acquisition", where he tries to fight a traffic violation on principle when a scene just before he finds out about his summons establishes he has several thousand dollars in uncashed paychecks.
• Social Darwinist: As shown when his guided meditation gets sidetracked by imagining Godzilla attacking SimCity.
  Sheldon: People of Sheldonopolis, this is your Mayor! Follow me and I will lead you to safety. If your children cannot run, leave them behind!
• Southern-Fried Genius: Subverted for the most part. Despite hailing from Texas, he displays none of the traits that are typically associated with the "redneck" aspect of the trope. This is apparently a conscious decision on his part; he reverts to his Texas drawl when angry, upset, under duress and a few times when drunk, even using idioms.
  Sheldon: Sure, why not?! And after the sun sets, we can pile up in my pickup truck and go skinny-dipping down by the creek (pronounced "crick" here)! Cause today's the day to stop making sense!
  • He is also very knowledgeable on American football, as being in Texas meant it was inevitable he would know (his dad would make him go to games and watch). He also knows how to chicken-fry pretty well (or as he puts it, "fry meat that is not chicken as if it were chicken). He's also very knowledgeable in handling firearms, because, well it's Texas.
  • He also notes that being from Texas, he can "taste the difference between rabbit and squirrel."
• Spin-Off: Because of his popularity, he later earns a show about his childhood in 2017.
• Spock Speak: Just let this example speak for itself:
  Sheldon: Well, 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 on its original trajectory and adheres to you. ^Translation I'm rubber, you're glue, bounces off me and sticks to you.
• Spoiled Brat: Sheldon tends to embody this trope, often getting whatever he wants, how and when he wants it, no matter how unreasonable, merely by being extremely difficult. Ironically, his family seem to be the only people not enabling him.
• The Starscream: He feels the need to be in charge of whatever the group is doing, just to give himself a feel of authority. The biggest example perhaps was when Leonard got an app idea and he immediately tried to declare himself in charge, while only listing Leonard as the "founder." After Leonard makes it clear he is in charge, Sheldon begins insulting every decision he makes, tries to get the app named after himself, and tries to vote Leonard out of leadership when he won't give in to his demands. After Leonard finally fires him he tries to sabotage the group by bribing Raj and Howard to join him instead and later prevent them from working.
• Strong Girl, Smart Guy: In Young Sheldon, he's the Smart Guy to Missy's Strong Girl. He is a smart and unathletic nerd, while his twin sister is a Book Dumb but athletic Cute Bruiser.
• Surrounded by Idiots: His opinion of everyone around him.
• Team Prima Donna: His huge ego and childishness always cause problems whenever he and the others try to work together on anything. Like the time they tried to make a cell phone app and Sheldon tried to stage a mutiny because Leonard wouldn't let him name the app after himself. Heck, his nitpicking and obsession with getting his way even makes going to see a movie a complicated project.
• Terrified of Germs: Sheldon is such a clean freak that he showers multiple times a day and constantly washes his hands.
• Token Evil Teammate: He's not actually evil but given the previous tropes that represent him is a different story.
• Took a Level in Jerkass:
  • In "The Itchy Brain Simulation", he goes from a merely annoying Innocently Insensitive jerk to an Evil Genius.
  • Sheldon continually insulting Amy after their breakup, even though it was entirely his fault over his inability to pick up on social cues and other people's feelings, comes across as incredibly juvenile and cruel.
• Took a Level in Kindness:
  • After he and Amy get back together, Sheldon treats her and all of his friends better than he did before, completely undoing the above Took a Level in Jerkass.
  • The adult Sheldon's narration in Young Sheldon shows that this future version of him, post The Big Bang Theory, is a far more emotionally aware and kinder person.
• Trademark Favorite Food: Spaghetti with cut up hot dogs.
• Trekkie: Star Trek is one of the group's favourite franchises. They especially dig Star Trek: The Original Series and ''Star Trek: The Next Generation'. Spock is Sheldon's favorite character.
  • This fact is eventually lampshaded in "The Spock Resonance": due to Sheldon's refusal to believe in the constant "What Would Jesus do" attitude of his mother to help with his constant bullying, he instead resorted to asking "What Would Spock do" and idolizing the character due to his approach to logic and rationale as opposed to emotions and belief (even if it still got him to be beaten up). Penny correctly points out that Spock's character is half-human, and therefore emotions are a huge part of his development in the original series and as a character overall, and by doing so demonstrates that he actually uses the character's basic description as an escape. Sheldon proves her right by digressing into a breakdown over his recent break-up with Amy and running to his bedroom.
• Troll: He's often guilty of this behavior, as demonstrated by most of his "Classic Pranks", his heckling of both Leonard and Brian Greene's lectures and when his continual swiping of the One Ring from Leonard.
  Howard: You're not helping!
  Sheldon: I'm not trying to help! [smirks]
• Tsundere: Platonic version towards Leonard. Although he constantly mocks Leonard for being a less-intelligent Experimental Physicist, he has constantly proven that he cares greatly for him.
• Twitchy Eye: Gets a very prominent one when he either doesn't know something, or the others don't let him finish explaining something.
• TV Genius: This is a huge part of the sitcom's premise. Leonard, Raj and Howard are also extremely intelligent, but nowhere near as TV Genius as Sheldon. To reiterate, in a show where five of the seven main characters have at least one doctorate (Penny has a high school diploma, while Howard only has a masters) and most of the recurring characters are university professors or otherwise in highly technical fields, Sheldon is universally regarded as bizarre. Not incomprehensibly so, however, as he literally came with a manual. That he himself wrote in PDF format and hands out to new friends.

U-W

• Übermensch: Sheldon has a slight disregard/disapproval of certain social protocols, his obsessive-compulsive behaviors are often seen as weird or overdone by his friends, and he outright considers compassion and understanding to be a limitation to himself. Despite all of this, Sheldon is an incredibly intelligent genius physicist, and it can't be denied that his zealous imposition of order on his household really does help himself as well as Leonard, despite his protests.
• Uncle Pennybags: Surprisingly — Sheldon's lifestyle is very low-budget and he saves his money, to the point he feels perfectly comfortable giving Penny enough money to both pay her rent and fix her car when it breaks down. Despite her assumption that Sheldon's obsessive tendencies would lead him to hound her, it turns out that he's quite calm about having to lend his money. He only lends money he believes he doesn't need in the first place, and honestly doesn't care when it's paid back, as long as it eventually is.
• Ungrateful Bastard: While he can repay a favor to someone, most of the time he's this to everyone. When his friends tended to him while he had the flu, he either rejected their help or repaid their kindness with complaining or insults.
• Unreliable Narrator: Almost everything in his life is skewed around his own viewpoint and perception of his own suffering, and as such will describe any given event as him being an innocent victim and everyone around him are morons acting out of jealousy. It becomes more apparent whenever dealing with his family members, as they have spent so much dealing with his egotism that they have little patience with him skewing the truth. His mother even says that his childhood bullying was in large part due to him being an Insufferable Genius.
• Unskilled, but Strong: In an intellectual sense. He's exceptionally bright, but has nearly NO technical/people/organizational skills and his default approach to problem-solving is to just stare at his whiteboard until a solution comes to him.
• The Unsmile: Masters it and is even the page image.
• Unsympathetic Comedy Protagonist: Sheldon's self-centered egotism and condescending behavior is the source of conflict for any given episode, even just by being sick and asking for help (his obnoxiousness at that stage is feared by practically everyone).
• Verbal Tic: Sometimes refers to things with unnecessary tautologies, such as "Green Lantern Lantern", or "Lord of the Rings Ring".
• Virtue Is Weakness: He actively believes that being compassionate and open-minded is a weakness, to the point that he (unsuccessfully) attempted to break up with Amy when he realized her effect on his personality.
• White Sheep: Sees himself as this, by demeaning bullies from Texas, including his family, as backwards idiots who don't appreciate his genius. He even wrote a Star Trek Fan Fiction about him being taken away from his family to the future. The truth is more complex, his family was middle class and had to dedicate a lot of their time and resources to Sheldon's education, who was already difficult to deal with. Both his siblings resent him to different degrees because of being Overshadowed by Awesome, their own modest accomplishments seem insignificant to Sheldon's genius.
• With Friends Like These...:
  Sheldon: Those are traits associated with a psychopath.
  Leonard: Are you worried about me killing you in your sleep?
  Sheldon: No, I imagine if you were going to do so, you would have done it years ago.
• Whoopi Epiphany Speech: Played with. While such a speech is usually one of great wisdom made by someone who isn't all that educated or book smart, it can't be said that Sheldon is either of those things. But he is very socially inept. So it comes as a surprise at times when Sheldon has rare gems of social wisdom (albeit wrapped in Sesquipedalian Loquaciousness) that give Leonard new insights he couldn't see before.
• Work Off the Debt: On Young Sheldon Sheldon takes on a paper route to pay George after he dismantled the refrigerator, costing his father $200 to get it restored.

---

"I was under a misapprehension that my accomplishments were mine alone. Nothing could be further from the truth."