Friends are great. Which is why having friends is often what separates the hero from the villain. An unfortunate and inevitable side-effect of The Power of Friendship is that if you don't have friends, there's something wrong with you, since being a loner is not "natural".
Similarly, if a writer is going to create a sympathetic Anti-Hero, they often choose to make the character a brooding and friendless loner. Introversion seems to get used much more often than other epic or humanizing flaws like pride, addiction, jealousy or lust. Perhaps this is because showing a complete lack of a social life as opposed to a self-destructive one is much easier to accomplish. A quick establishing shot of a character sitting alone in a social setting is an easy way to alert the audience that something isn't quite right.
Fiction also doesn't seem to draw a distinction between being asocial, and anti-social. A loner character usually is more than just socially awkward, they'll have a number of serious psychological issues too. Arrogance, selfishness, and mentalinstability are all fairly common. At worst, they're portrayed as evil since their refusal to socialize is proof that others are not worthy of their presence and that the only person they could ever care about is themselves. Right? When fiction doesn't make a distinction between being a loner by choice or being driven to it, this is the attitude at work.
Cultural norms can make this even worse. In Japan, Hikikomori are seen as either NEETs gone over the edge, or lazy students cutting class rather than victims of a nearly-Social Darwinist society defined by ambition and fear of shame. Rather than reaching out for help, the family is expected to isolate the weirdo from society and deal with the problem themselves.
Even more unfortunately, there is somehistoric basis for this; humans are social animals. Cooperation along with the invention of language is how we survived and those who were alone often weren't able to reproduce or hand over their innovations to the next guy. Through most of human history collective action was the only practical means of survival; being extremely selfish, hiding all the time, or being shunned/banned/exiled/cast out was very often a precursor to slow death by starvation and predation. Thus a person condemned to Dying Alone was almost certainly alone because of a problem he'd had fitting into another group and thus he should be avoided.
A loner can also become a freak through isolation. Humans learn how to be human through social interaction. And there are many social skills that can only be learned in person — isolation can lead to No Social Skills. When you're raised in isolation, you behave differently. Many psychological disorders originate from a deficit in human interaction. Then that person will be shunned, isolating him further in a vicious cycle, putting him closer to the Despair Event Horizon.....
A more tragic explanation for this trope is that loners are simply expressing their true personalities (in this case, being a loner) by refusing to adapt to societal standards they don't like. This can be interpreted as being an act of rebellion by others when nothing deeper is really going on. Thus, many introverted people are assumed to be going through an immature stage or dismissed as having ulterior motives for their behavior that ends up just isolating them more.
Of course, this trope could just be the inversion of the idea that nobody could like a freak, so freaks are loners. This doesn't logically translate to all loners are freaks, but a lot of fiction doesn't follow logic.
In idealistic works concerning this trope, the All-Loving Hero will often affect a Heel-Face Turn on an antagonist by trying to be their friend. Often this will work by itself, hammering home the idea that what's wrong with the villain isn't the need for revenge or a severely unbalanced psyche, it's a lack of friends. Even if The All-Loving Hero eventually accepts the Loner as a Loner, the Loner will often appreciate the effort, and begin making token attempts to be sociable with the True Companions.
It's hard to determine whether this trope originated from assumptions about loners in the real world or helped cause it...or whether that's another vicious cycle.
There are exceptions, as with all other tropes: the crusty old hermit or Witch Doctor who rebuffs the villains and helps out the heroes is a fairly popular stock character. And both of those are frequently portrayed at the very least as eccentric. The Misunderstood Loner with a Heart of Gold is a subversion. The Snark Knightdeliberately seeks to defy this trope.
And, as Freaks proved, loners may be freaks, but freaks aren't loners.
Compare The Complainer Is Always Wrong and perhaps Intelligence Equals Isolation. Contrast You Are Not Alone. See also No Social Skills.
In Neon Genesis Evangelion, everyone is a loner to some degree, and it does none of them the least bit of good. Shinji is the most lonely, because of all the depressing, horrible, and just plain sad things that happen to him. Watching his mother die, being forced to pilot EVA-01 by his father, getting little respect from his peers and/or being bullied, watching EVA-01 tear a rogue EVA to shreds beyond his control, and later finding out that the pilot was one of his friends who is now crippled as a result, being forced to kill the only person who truly understood him, and being forced to activate an apocalyptic event, leaving him and Asuka the only two people on Earth.
Rebuild has an aversion in the form of Mari, who outright states that she doesn't like involving others in her plans, deliberately cuts off the intercom when she hijacks EVA 02, and is hardly shown talking with anyone but the protagonist. She still manages to be a very positive, badass character who teaches said protagonist an important lesson.
One of Ash's rivals, Paul, from Pokémon, seems to be taking this route. He doesn't even seem to form proper friendships with his own Pokémon. He's only interested in them for their power.
On Digimon Adventure, the evil Puppetmon was defeated specifically because he had no friends.
In a sense, all of the evil Digimon were destroyed because they were loners. Puppetmon was simply the only one who had it spelled out to him, by both the Digidestined and Cherrymon (his childlike nature also meant that he angrily rejected the notion that no one was his friend).
The relationship between Naruto and Sasuke reeks of this. Sasuke, a loner due to a strong, all-encompassing desire for revenge, and power for the sake of that revenge, ends up becoming a Rival Turned Evil due to his pride being damaged by both Naruto's ever increasing power and an ass-kicking/Mind Rape by his Aloof Big Brother Itachi. Though after the time skip Sasuke seems to be clearly one of the most powerful ninja on the planet.
But he's also increasingly off his nut and evil. This trope in relation to Sasuke was made pretty clear with him sacrificing Karin without a second thought to get to Danzo.
Gaara exemplified this before his defeat by Naruto. Constantly ostracized by his village, he had retreated into solitude and gone gradually more insane as doing so only strengthened Shukaku's hold on his mind.
Naruto's response to his backstory also fits. His first reaction was to fear Gaara because he thought someone who could willingly accept such loneliness must be incredibly strong.
Exception: Kino of Kinos Journey is remarkably well adjusted and prefers to travel alone with just a talking motorcycle (yes) for company. Kino doesn't hate people, but doesn't want to form attachments that would hinder the ideal of the Traveler. It helps that most people and societies they encounter are really screwed up.
The main message of One Piece boils down to "if you don't have any friends, You Suck!" It's actually difficult to stay a loner in One Piece unless you're really a douchebag and therefore, deserving of it. Consider Tony Chopper, a talking, shapeshifting reindeer, who was outcast for his weirdness until Luffy's crew comes along and openly accept him.
Also, Zoro, Robin and Brooke. Zoro was even alone by choice. Also worth mentioning is Arlong, who cares as much for his True Companions as Luffy, and is a vicious bastard.
Played straight in a very realistic way by Brooke who's fifty years of complete isolation drove him mad.
Death Note does this in different ways, with L being the most straight-up example of this trope. Light seems to be his polar opposite, being very popular at school (apparently), and having a very devoted following for his alter ego, Kira. However, Light doesn't seem to be close to anyone in his life, and sees his girlfriend Misa as more of a tool to reach his goals. It turns out he and L are really Not So Different.
The Diclonius in Elfen Lied are rejected by society. As a result, most are either depressed or (more commonly) sociopathic, sadistic killers.
It's worth noting that all of them are psychotic to varying degrees and/or have split personalities.
In Berserk, the half-mad main character, Guts, finally relents and allows others to follow him after wandering alone battling demons for years. They eventually become True Companions, but he goes off to being a loner again, which is one of the main causes of everything going into shambles since Griffith is obsessed with him. The sad thing is, he only left the Hawks because he wanted to be a better friend and peer to Griffith, and he believed that he couldn't do that unless he could find a dream of his own.
Princess Tutu has Autor, a character who is first introduced by several cameos of him sitting alone in a library, yelling at others to be quiet while employing Scary Shiny Glasses. Once he becomes integrated into the plot, it appears that he doesn't have many friends because he's consumed by his obsession with Drosselmeyer (as well as a belief that he's better than everyone)—although there's occasional hints that he's bothered by his position, including him having an angry reaction to Uzura calling him "Weird Autor". In the end, he helps give Rue an epiphany using The Power of Love, and also saves Fakir, possibly hinting that he's come to accept the boy as a friend.
Johan of Monster would be a aversion of this trope, as he's very charismatic... if he didn't kill everyone that ended up being his friend. Though it could be argue that he never considered anyone his "friend."
The closest things he has to friends are Tenma and his own sister Nina, the people whose lives he made hell and whom he tries to mindrape into killing him over the course of the series.
While the heroes of JoJo's Bizarre Adventure slowly gather friends over the course of their bizarre adventures, the Big Bad of the series, Dio Brando, also has an ever-expanding group of friends/minions who are extremely loyal to him. It's even noted by Joseph that this is part of the reason why he's so dangerous (besides the vampire powers and time-stopping).
A more direct example is Part 4 Big Bad Yoshikage Kira.
Sousuke Sagara from Full Metal Panic!specifically tries not to get too attached to people, mainly because he wants to maintain his business-like, cold way of following orders. Unfortunately for him, people just seem to be so attracted to him that, even if he doesn't want to, he constantly ends up with groups of True Companions. Gauron becomes rather angry when he finds out that Sousuke is constantly surrounded by friends, and breaking speeches Sousuke about how being a loner is a good thing that makes him strong and unique. Funniest part about it is that Gauron himself kept two very loyal girls by his side, making it more likely that his grand speech had more shallow reasons.
The plot of Welcome to the N.H.K. is how the protagonist Satou tries to get over his social anxiety and connect with people after he realizes how unhappy he is as a loner.
Averted in Mahou Sensei Negima!, oddly enough. The hero himself is a very kind person, but is also formal and uses Keigo with almost everyone. He tends to be rather distant otherwise. As it's an aversion and not a subversion, he's a loner but has no pathological case of avoiding people, he just doesn't socialize.
He also doesn't have a lot of time to socialize because he's constantly going through Training from Hell. However, he does tend to grow closer to the students who are training alongside him.
He probably uses Keigo because Japanese is not his first language, and the more formal ways of speaking are generally taught first when someone is trying to learn. Keigo being the first way of speaking Japanese that he learned, he's probably most comfortable using it.
This isn't true actually, he knows how to speak in an informal manner and does it with the Kotaro, Takahata-sensei and Anya, as pointed by one of the students.
It also doesn't help that Negi has a huge helping of survivor's guilt after what happened to his village and wants to keep people away, in case they suffer the same fate as everyone else.
Being alone is a common factor for 'mad' characters in Soul Eater, right up to the original Kishin who rejected everything and everyone out of fear. Whilst being alone has not been explicitly stated as being bad, the way the alternative is presented makes the implication clear.
Crona was at the point of becoming a Kishin, did not know how to "deal with" people and their soul was represented as a desolate landscape until Maka intervened. Once Medusa gets her child back, however, things get worse and Crona has recently rejected any reminder of the friends they found at Shibusen.
Black Star became more detached from people when pursuing a misguided attempt at becoming stronger. He challenged teams without his Weapon partner, becoming increasingly...odd to the point that a comparison was made to his kishin fahter. Tellingly, he got over it by listening to and cooperating with Tsubaki.
Being a lone Weapon is one of the fandom theories regarding Justin Law's Face Heel Turn, especially considering he appears to have encountered the Clown whom Maka and Soul 'defeated' through epic team-work. In fact, teamwork forms the basis for all of the significant victories of that pair (if not all of the meister/weapon groups) in the manga.
While Stein does get on with people to an extent, he does not exactly seek out company. Marie leaves Death City with Stein because "he is always alone". Spirit was told by Shinigami to keep an eye on Stein, something which he has apparently been doing since childhood.
Shizuka of Bakuman。 is a basement-dweller who writes truly messed-up plotlines, barely acknowledges his beleaguered, well-meaning editor, and regularly sports truly terrifying facial expressions. When this boy snaps, it'll be something on the order of the Staff of the Magi.
Yukiteru Amano of Mirai Nikki is very much a loner at school, due to his own reclusive and anti-social personality. The other kids consider him to be a freak. He does grow out of it later on and gains a small circle of friends after deciding he never liked being alone, but unfortunately for him, Yuno Gasai considers herself the only friend he needs.
Konata from Lucky Star, while not being a true loner, often gets berated for her love of solitary activities, like playing video games or watching anime shows.
Kagami in particular sees Konata as the stereotypical otaku and/or hikikomori, and considers Konata as a potential criminal. (To be fair, Konata lacks most stereotypical otaku and hikikomori traits.)
Tenshi/Kanade Tachibana of Angel Beats! is placed in this category, but is rather a Boo Radley. She's seen as a freak because she doesn't have any friends, but that's only because She's actively trying to graduate those around her, and thus is never really seen with anyone for any length of time.
Averted in Amanchu!. We never see any of Hikari's friends from before she met Futaba and the rest of the diving club, but she is shown to be cheery and outgoing, although perhaps a bit eccentric.
All over the place in Puella Magi Madoka Magica. Homura doesn't have any friends because she was hospitalized for a long time, Mami doesn't have any friends because she must distance herself from others due to her job, Kyouko doesn't give a damn about humans after all she went through, and Sayaka actually become freaks, in so many ways, when she decides to be a loner. In contrast, Madoka try to connect with them all.
In Heaven's Lost Property, Eishirou Sugata is supposedly this, complete with living in a tent, by a river, on a FRIKIN' mountain. And yes, he is weird as hell, according to Tomoki Sakurai, who is weirder, so it's weird coming from him. Though, after meeting Tomoki and co., he kinda started following them around.
Played with in Fairy Tail. Marakov finds Gajeel bumming around after Phantom Lord was defeated. When Gajeel insists that he is fine by himself, Marakov points out that some people prefer solitude, but no one likes being alone.
Zig-zagged in Haruhi Suzumiya with the title character. She starts out a loner—no friends, refuses to join any clubs—and is seen as a disruptive weirdo by pretty much everyone. Then she starts the SOS Brigade...and becomes ten times as destructively obnoxious now that she has a team of "friends" to do her bidding. But, after a while, she experiences Character Development and becomes less of a jerk thanks to being around other people; although they're trying to pacify her more for the sake of the stability of the universe than for her own benefit.
Averted in Astérix and the Roman Agent: while everyone else is bickering thanks to the titular spy's influence, the bard Cacofonix isn't, since he, besides being aphonic at the time, usually keeps to himself and thus keeps away from the agent's jealousy- and paranoia-inducing influence.
Batman himself seems to think he is a loner, or that he needs to be something like that to keep himself at the top of the game, but he also acknowledges several people as family or friends, even if he keeps them at a distance at times, and is generally aware that he needs them for the sake of his own sanity and humanity if nothing else, and that he cares deeply for them. After all, he is a man driven by personal loss.
On the flip-side, The Joker is one of the most extroverted villains in all of fiction. He usually has a gang, and a very large one, has a girlfriend in Harley Quinn and is very fond of the Villain Team-Up both with regular Batman rogues and on the grander stage with guys like Lex Luthor. Of course, he is a Bad Boss to said gang and tends to kill members at random on a whim; his relationship with Harley Quinn is the Trope Namer for Mad Love, and though he might like teaming up with other villains, the other villains are afraid to team up with him. He's not a freaky loner; he's the freak you wish was a loner, because with friends like him, who needs enemies.
Averted with the Rogues Gallery of The Flash, who are very sociable to the point of acting like a club as much as a loose association of criminal masterminds.
Both Rorschach and Dr. Manhattan of Watchmen. Rorschach has difficulty relating to people on a social level, being paranoid, violent, and insulting. Dr. Manhattan pushes away from humanity due to his god-like powers.
It's implied in his back-story that Dr Manhattan wasn't the most gregarious man in the world even before becoming omnipotent, omniscient and probably omnipresent if he felt like it.
In many Legion of Super-Heroes continuities, Lightning Lord's misanthropy is at least partially attributed to this. His homeworld, Winath, has a population composed mostly of twins. As a single birth, he was apparently treated with pity, disdain and suspicion, and didn't take it well.
Doctor Doom regards friendship as a sign of weakness. He does have a handful of people he is relatively close to, but he refuses to call them "friends" because he imagines himself to be entirely self-reliant and superior to other men, and he keeps them at an emotional distance. Said "not-friends" are really his most trusted minions, anyway. He had a long-lost love called Valeria, but when he sacrificed her to a trio of demons for power, that kind of went out the window. He is not entirely asocial though and is Affably Evil enough to offer his female opponents a feast while their male teammates languish in the dungeons. Also, he has an annual dinner with the mercenary Silver Sable in her role as ambassador for the neighbouring country- apparently, she looks forward to them as Doom is a very good host. And he truly wants his own people to love and respect him and is relatively nice to them in return. Also, he has a very big soft spot for Valeria Richards, his god-daughter who he helped deliver (she gets away with calling him "Uncle Doom"), and has placed her under his royal protection (you harm her, he makes you pay).
Thanos of Titan was born with the Deviant gene, meaning he was an Eternal like the rest of his people but looked like a member of their historical mutant enemies / genetic cousins. He became a loner because of this and eventually killed nearly every other member of his race in a nuclear holocaustFor the Evulz. He claims that the other Eternals treated him like an outcast, but his surviving brother says that Thanos imagined this and was just naturally reclusive and paranoid, and obsessed with Death and Black Magic and other dark ad grim subjects that didn't exactly invite company.
Sarah from from Bazooka Jules is an anti-social girl that goes to Julie's school. She's nicknamed weird girl because she has no friends and spends a lot of her time talking to her imaginary friends. The only person that wants to be her friend in Julie and she hates Julie.
X-23 is already a withdrawn and quiet girl as a result of her Dark and Troubled Past, but then she goes through phases where she isolates herself from others entirely. In NYX she rarely speaks and creeps out her companions, and in the beginning of her solo series Laura mostly avoids the other younger mutants and has been spending most of her time alone after being pulled from X-Force. The other students are quick to comment on this.
Shadow Snark after being in self made isolation for a few years, he has No Social skills
10 Things I Hate About You. Julia Stiles and Heath Ledger both play social outsiders. In reality they are rather mundane, but their rejection of society causes people to assume everything they do has some dark or criminal explanation.
Brendan Frye in Brick is cool, and badass, and a perfect example of Determinator, but he eats lunch alone and the only two people who could possibly be called his friends are his ex-girlfriend and Brain, who serves as a sort of information broker. Brendan plays many sides against each other, and is not very well liked for it.
However, he does run with a pretty large gang, and seems to pick up new members out of nowhere and know where all the criminals meet.
It's noted that a good chunk of his men broke out from Arkham in the previous movie, and he also seems to absorb the lower ranks from the other mobsters he kills into his own gang, which would give him a) intel on the other criminals and b) underlings who aren't completely Ax-Crazy. Just mostly.
Averted in Silent Running - protagonist Freeman Lowell is a loner who is more at home with plants and animals than with people, but he's also the good guy in comparison to his uncaring, mercenary crewmates.
And he's got his droids, so it's not really that he doesn't want company, he just wants better company.
Taxi Driver's Travis Bickle just can't get a grip on relating to people. So he turns himself into a walking arsenal and decides to do some damage/good.
In the film version of How the Grinch Stole Christmas!, the Grinch complains about this trope: "Fat Boy should be finishing up anytime now. Talk about a recluse. He only comes out once a year, and HE never catches any flak for it!"
About a Boy features Hugh Grant in the loner role. Over the course of the film he learns how to be a decent human being by making some friends. (starting with a 12 year old boy, no less!)
WarGames is driven by the fact that the hero is a lone geek (apart from a highly unlikely girlfriend for dramatic purposes.) Which is one of the things that dates the film, since today he would have a whole cyber-community "World_Destroying_Online_PC_Games.net".
In Tangled, Flynn even admits that his dream involves him being alone and has to be forced into participating in the Crowd Song and the Dance Line. One Snuggly Duckling tavern thug explicitly tells him that his dream is stupid before the Character Development that led him to repudiate this.
Although what they seemed to have the biggest problem with was that while everyone else dreamed of doing things, Flynn just dreamed of getting lots and lots of money.
Played for laughs in Grosse Pointe Blank: One of the characters is an assassin who is trying to start up a trade union for assassins and approaches the main character demanding that he join. The main character argues the absurdity of the idea by pointing out that most assassins tend to be disaffected loners who don't work well with others:
Martin: Loner! Get it? Lone-gunman! That's the whole point!
Solomon Kane is the poster child for this trope, spending almost every story tramping around Darkest Africa all alone except for the Witch Doctor N'Longa, who he sees very infrequently, and various other characters whose main function, generally speaking, is to die violently.
Roland Deschain, the protagonist of Stephen King's magnum opus The Dark Tower, suffers from this trope: he has been alone for so long in his quest to reach the titular Dark Tower that it is his only reason for living. In the first book he goes so far as to let a twelve-year-old boy he rescued and bonded with to fall to his death, just to because his nemesis said it was the only way he'd ever allow himself to be caught, and said nemesis seemed to know about the Dark Tower. Roland's character softens into something a great deal more sympathetic after he forms a traveling party that helps him in his quest — which includes what amounts to a resurrected version of that kid, who'd have to be insane to follow Roland again under any other circumstances.
Susannah is clearly thinking of this trope when she thinks about how "the desert made him strange."
A key plot point throughout the series is that Lord Voldemort's lack of understanding of and inability to love another person or thing is one of his greatest weaknesses (he's actually a full-blown sociopath), whereas Harry's ability to love is his greatest strength. That said, Harry is a bit of a loner, of the more harmless variety. In fact, he is often mistaken for a freak, particularly in books 2, and 5, and his relatives think he's one too. Voldemort was also said to be quite popular when he was younger, and his followers, the Death Eaters, include many people he knew from school, although he tended to dominate his underlings and by the time he comes back its clear that most only hang around him out of sheer terror.
The young Severus Snape is also depicted as a loner, unpopular and often bullied, further tying him to Harry and Voldemort as one of JK Rowling's three "abandoned boys."
In the last book with Dumbledore is revealed to be a true loner himself. While adored by the entire wizarding populace, Albus never seemed particularly close to anyone- the most fondness we see him express over the series is for his old flame Grindelwald and for Harry. Part of this is explained because his genius made him feel isolated, but by the last book, it becomes very clear he didn't trust anyone with all of his secrets, preferring to kill Voldemort with a Gambit Roulette. While Dumbledore is adored by all, most of the time, his intense quirkiness can lead to him being seen as a freak, as throughout The Deathly Hallows, Harry grows increasingly disillusioned as it sinks in how little Albus trusted him. However, this is ultimately a Downplayed Trope with him. JK Rowling says on Pottermore that Albus Dumbledore and Professor McGonagall were quite close, bonding over similarities in their childhoods. Albus and Aberforth Dumbledore were also reported to be relatively close before everything went wrong.
Luna Lovegood lampshades it when she says she has no friends because everyone thinks she's weird.
Enders Gamedoubly subverts this. Everyone intentionally isolates Ender to make him a more efficient commander. Which also makes him an asocial freak that he never really gets over. But useful!
Enders Shadow goes back on this a bit, playing up the fact that Ender relied on his army while Bean was the real antisocial genius. Or, to be more accurate, Ender could project all the leadership qualities and bind their loyalty to him but was completely alone himself, except for Bean, who had no idea how to really connect to other people. This is something of a plot point and stated outright: Ender takes down his bogeyman by himself whereas Bean has learned how to form a team that may or may not actually like him, but accept him.
The subsequent Shadow books do this even more clearly. Who's the villain? Achilles, who seems to be able to make everyone, except some of the battleschoolers, love him. He feels no attachment to them and is noted by Bean near the end as being empty and unable to understand true bonds. Who're the heroes? Bean, Mr. Antisocial himself, although it is revealed that his detachment from humanity is more about him caring too much than too little. And Peter Wiggin, the terror of his brother's life and the ultimate "I can do it myself" loner. Until he realizes just how good his parents are to talk to and after he marries Petra.
Harry Dresden of The Dresden Files is a loner of the harmless variety. He has a small circle of friends, but he's more or less antisocial, only being immediately nice to pretty girls (not because he's a pervert, he's just the chivalrous type). People treat him as a freak, but not because he's a loner. It's because he publicly advertises his being a wizard and people think he's nuts. This is only really an issue in the first four books. During and following Summer Knight, Harry finally accumulates enough True Companions that he can no longer really be considered a loner.
Played with extensively in Gordon R. Dickson's Childe Cycle series of novels. The "main character" of the series, Donal Graeme, finds he cannot accomplish his goal of uniting humanity alone; he not only has to travel in time (though not in the same body) to not only set historical events in motion, but to change their significance in history so that not only events but people are in place for a Final Battle. The trope listed here is also subverted in Soldier, Ask Not where a newspaperman with the power to influence people is thwarted in his attempts to bring down a entire race by one person of Faith, acting as he sees fit; and played to a extreme in the short story Brothers - about a set of twins that embody this trope. When one is killed, the story follows the other in his pursuit of the murderers, and leads to one of the most powerful scenes I have ever read, at the end.
Subverted in The Andromeda Strain. The Odd-Man Hypothesis states that unmarried males should be given command during times of crises, as their lack of attachment allows them to make the most unbiased decisions.
Played frustratingly straight in the Kitty Norville series. Werewolves do not do well without a pack, and the further from civilization and multiple friendships, the worse the resulting monster becomes.
Played with in any Ayn Rand novel. Typically, villains or idiots believe this trope to be true, and most of the heroes are loners. The loners themselves consider the trope false, although they tend to get along with each other. Ultimately, Rand tends to invert this trope, although some of her heroes (Francisco d'Anconia in Atlas Shrugged and Austen Heller in The Fountainhead for example) are pretty sociable.
Speak: This is the reason Melinda is spurned by her classmates at school, other than the police-calling incident.
Everworld: Senna Wales. The first book, Search for Senna notes that she "was not the most popular girl at school." She doesn't allow anyone to know anything about her personality or motives at first, not even her boyfriend, David Levin. Later in the book it becomes apparent that she is an antisocial, scheming witch who is running her own plans. And that's the first thing we learn about her.
It was said later that he came under bad influences at this stage. But the secret of the history of Edward d'Eath was that he came under no outside influences at all, unless you count all those dead kings. He just came under the influence of himself. That's where people get it wrong. Individuals aren't naturally paid-up members of the human race, except biologically. They need to be bounced around by the Brownian motion of society, which is a mechanism by which human beings constantly remind one another that they are ... well ... human beings. He was also spiraling inwards, as tends to happen in cases like this.
Another Discworld example, played with A Hat Full of Sky. Witches tend to dislike other witches nosing in on their business, and it's repeatedly made clear that witches are not necessarily people people ("among the people, but not of the people"), but it's still important for them to visit each other occasionally to make sure they haven't gone bonkers.
Sherlock Holmes, arguably embodies the loner trope, with the exception of Dr. John Watson.
That said, he and Watson were introduced by a mutual acquaintance, and Holmes keeps some measure of contact up with his brother.
Dupin and his anonymous narrator in the works of Edgar Allan Poe are even more isolated than Sherlock Holmes and Watson although they still retain certain contacts in the police that allow them to carry out their amateur detective work.
In fact, an Alternate Character Interpretation is that Victor Frankenstein is the villain and the "monster" his victim. The monster himself points out that Victor created him and then immediately abandoned him, never allowing him to know love or affection. It poses a sort of chicken-or-egg question: is the monster a loner because he's a freak or is he a freak because he's a loner?
Victor himself was a Mad Scientist loner-freak when he was busy creating the monster, and was upset to find that when he arrived at university most of the science he studied- really what today we'd call alchemy and the occult- was deemed to be out of date, and took to trying to prove its worth on his own. He notes that he became less and less sociable while creating the monster, and tried to get over his sheer horror of what he had created by throwing himself back into human company and abandoning his research.
My God, mannie, if Freckles hadna the birds and the beasts he would be always alone. It was never meant for a human being to be so solitary. He'd get touched in the head if he hadna them to think for and to talk to.
The Cardinal was left boasting and strutting in the sumac, but in his heart he found it lonesome business. Being the son of a king, he was much too dignified to beg for a mate, and besides, it took all his time to guard the sumac; but his eyes were wide open to all that went on around him, and he envied the blackbird his glossy, devoted little sweetheart, with all his might.
Tobias has a lot of this in Animorphs after he gets trapped in morph. He does spend a lot of time with the other Animorphs, but he also has periods as a loner because he struggles with his triple hawk/human/Andalite nature and figuring out where he fits in in the world. It gets taken Up to Eleven at least twice when he retreats from everyone and sometimes even lets the hawk take over-right after he gets trapped and after Rachel's death.
Arguably, David. He moved around a lot as a human, and eventually gave up on maintaining close relationships. Could explain why he went axe-crazy in the end.
In Poul Anderson's "A World Called Maanerek", Torrek is at first horror-struck at Sonna's suggestion that it does not matter that he does not know who his people are, because what is a man without his family and clan — only later does it calm him.
While Elena is going through Godmother training in The Fairy Godmother, it's brought up that Godmothers need a certain amount of contact with others to keep them from flipping out. This would have been averted for Sorcerers/Sorceresses, who are claimed to spend large chunks of their lives in isolated study (without going bonkers), if it weren't for the fact that the Sorceress with the most page time is Arachnia, and fixing her up with a good man was the cure for her problems.
Zahrah in Zahrah the Windseeker tends to be introverted and shy, which doesn't help her reputation for being weird since she is already dada (born with dreadlocked hair with vines in it). She faces this stereotype all the time.
Scott in Hobgoblin wants little to do with his high school peers and they want little to do with him. This also makes him a primary suspect when people start dying.
Live Action TV
In the pilot of Selfie, Henry's boss tells him to bring a date to his daughter's wedding, saying its weird how he's always alone.
Seventh Heaven: When Lucy Camden tells her mother about a girl in Habitat For Humanity who's a loner, Annie actually says she believes nobody really enjoys being "alone," and that there always must be some problem behind it. Sure enough, the withdrawn girl had been molested by her mother's ex-boyfriend.
An interesting inversion of the trope can be found in the British spy series The Prisoner, which features an unrepentant, mildly misanthropic loner as its protagonist. Instead of being seen as a liability, the character's "loner-ness" and drive towards individualism is the only thing keeping him sane. It's also the only weapon he has against the shady government officials who want to brainwash him and turn him into an obedient and conformist government servant.
It's played straight in one episode, however, in which Number Six manages to make contact with other subversives within the prison; however, because they're all confident-but-intensely-secretive and insular types, they all think each of them is a double agent and end up scuttling their own escape. If they'd just trusted each other, they'd have gotten away.
Dr. Cox from Scrubs applies to this trope as well, but a subversion occurs in the second episode of the first season. JD reaches out to the curmudgeonly doctor with pizza and beer, and just when it appears he's on the brink of a breakthrough, Dr. Cox replies, "I can braid your hair. I know the couch isn't very deep, but we could move the back cushion and spoon." Not only has he been sarcastic this whole time, he's got friends coming over to watch the game — they just don't include JD. This is the only time we see Doctor Cox with friends over - an episode later in the show sets up the same premise, but closes on Cox alone in his apartment with a six-pack...
However, he is occasionally seen out in the bar with the other members of the cast, or just his ex-wife. And a few episodes have him hanging out with old friends from before he became a doctor- in fact, part of the reason he is a loner is that his best friend, Ben, died of leukemia in the middle of the show (and had been travelling the world alone to boot). As the series rolls on he also strikes up a friendship with Arch-Enemy Kelso, going to Friendly Enemy to mentor (after Cox get's Kelso's job) and finally just to friends. He's fairly friendly with Carla and gets on well enough with everyone else, and JD eventually manages to trick him into admitting that he thinks of them as friends as well. Cox wants people to think he is a Jerk Ass loner, but in truth he has a decent circle of friends.
Averted in Veronica Mars, where the titular heroine is a loner in season 1. Later seasons acknowledge the trope's effect, however, as Veronica sporadically feels guilty about the fact that she really operates better alone.
In season 1 of Gilmore Girls, Rory is criticized by her headmaster for being too much of a loner.
Smallville, obviously, where all loners turn out to be crazed mutants, though a fair number of popular kids in that show turned out to be evil too. It lacks even the tiniest bit of sympathy for anyone who isn't attractive and outgoing. While popular party-going types do sometimes go bad, the show has never featured a real geek or nerd or loner as anything other than a hideous loser with serious issues or hideous deranged monster.(Chloe does not count, due to her failing the "unattractive" test by a country mile)
Parodied in a sketch on Jam, in which a desperately lonely woman goes to increasingly sinister lengths to make friends (from setting traps for cyclists to dressing as a police officer, telling a woman that her son died in an accident, then inviting the grieving mother to the theatre that evening)
Played with in the episode "Frescorts" where Ned insists that just because these people are lonely it doesn't mean that they're freaks. Emerson thinks it does.
In the same episode, a visible inversion occurs: Buddy killed Joe because he (Joe) decided to quit to be with his girlfriend, which Buddy saw as abandonment. Ho Yay + Clingy Jealous Boy = Uh oh. Also, in the end, Randy tells Ned that Joe had taught him that there's nothing wrong with being by yourself.
Various examples in Star Trek, for example Soran and Khan are loners. Also the Evil Twins are usually loners: Lore was abandoned on a planet for a long time, and Thomas Riker lived 8 years alone on an outpost.
Soran is not the best example, considering it was the loss of his family and desire to get back to them that made him go la-la.
Khan wasn't really a loner; more so just the burden of being a Magnificent Bastard caused him to always be just slightly above everyone else. He had his wife on Ceti Alpha V for a while, and throughout the movie, he's seen conversing with Joachim as a good friend, even promising to avenge his death (though he ignored the fact that Joachim himself blamed his death on Khan's obsessive quest for revenge, not on the ship firing at them in self-defence).
Thomas Riker's kind of a questionable example as well. Most of the conflict in the episode he appears in comes not from having been alone for so long, but from his resentment of Will for having lived those years while he was trapped. Neither is he really "evil" when he appears in Deep Space Nine; he's working for the Maquis, sure, but that's morally ambiguous; and again, he doesn't seem to have joined them because of his time alone so much as to differentiate himself from Will.
Reginald Barclay might be a better example. In his first appearance, he is shown as very much the Loner and his re-creation of members of the crew in the Holo-Deck is regarded as somewhat freakish. During the show, as he gains respect from his colleagues, he becomes less of a loner and deletes almost all of his Holo-Deck programs.
But on the other side, the power of collective is often described as evil as well, like Borg Collective and the Great Founder Link.
Desperate Housewives sometimes plays this trope straight (Eddie Orlofsky, Felicia Tillman), sometimes it averts it. There's Karen McCluskey, who is first introduced as an insufferable old loner, but then we find out that she still suffers for her son's early death.
Criminal Minds plays with this trope in every permutation. Sometimes the unsubs are revealed to be loners or anti-social people, sometimes they're perfectly sociable. In one episode, the BAU investigate a triple murder that seems to be perpetrated by a Satanic cult and turns out to be one of the popular kids at the high school framing the Satanists.
Played with in one scene where Elle is profiling an arsonist:
Elle: This guy doesn't go on dates, doesn't go to parties, doesn't feel comfortable in front of groups...
(The team's socially awkward Badass Bookworm, Reid, gives Elle a strange look.)
Elle:(quickly) And of course he's a total psychopath.
Reid: Of course.
Given an interesting twist in "Solitary Man" where the killer essentially went crazy from loneliness, and that's what turned him murderous.
Simon Bellamy from Misfits has no friends, and he's portrayed as mentally unstable, obsessive, nerdy, and a bit of a pervert. To be fair, he does actually want friends and genuinely tries to reach out to people, it's just that years of bullying and isolation have left him painfully shy and socially inept. Plus he's actually shown to be far more kind, sensitive and empathic than most of the show's more extroverted characters, and his Sanity Slippage is mostly due to the traumatic things that happen to him and the fact that no one really offers him emotional support (or even acknowledges his existence most of the time).
House and Foreman are sometimes accused of this, especially by The Chicks (Cameron and Thirteen).
As a result of his father's training, Dexter Morgan is aware of this, and goes out of his way to cultivate a "reserved but sociable" persona to keep from being thought of as an emotionally withdrawn loner. It works on everyone but Sgt. Doakes.
A case of "Loners become freaks" in Life, where Charlie is clearly a well adjusted guy with a job and a wife and friends until he spends an ungodly amount of time (unspecified, but measured in years) in solitary confinement. When they let him out again, he's kind of crazy.
"The first six months in solitary, I did push ups, and I did not talk to myself. The next six months in solitary, I'll admit, I talked to myself. You don't want to know what I did after that."
Parodied in the Buckwheat assassination episode of Saturday Night Live. A series of people who knew the assassin, John David Stutts, all say the same thing about him—"He was a quiet guy, a bit of a loner, but he always talked about wanting to kill Buckwheat." The caption under his high school yearbook photo reads, "Most Likely to Kill Buckwheat."
Ranger Gord on The Red Green Show is a tragicomic example, in that being posted to a lonely tower to watch for forest fires and then forgotten by his head office has meant that he's lived all alone in the woods since about 1979. Being all alone out there has made him into a full-blown Cloud Cuckoo Lander, something Lampshaded by Red on multiple occasions.
Buffy the Vampire Slayer had an episode called "Out of Mind, Out of Sight" about a girl who'd magically turned invisible from social ostracization and set out to take violent revenge on everyone she deemed responsible.
Also implied to be why Buffy is such an effective Slayer. Her ties to the world give her something to fight for, while other, more isolated, Slayers tend to have far shorter lifespans.
Also in Angel, the titular character has a lot of this in his backstory, due to his guilt and not wanting to risk attacking anyone. He came out of it for most of the series, though he sank back into it in season 2 in an attempt to protect everyone from his darkness like before.
Degrassi The Next Generation has Rick. He was constantly bullied by the likes of Spinner and Jay. And when he was abusive toward Terry (which may or may not be associated with a mental illness), the amount of hate toward him skyrocketed. It got to the point where, after being humiliated at a televised academic competition, he brings a gun to school, and shoots Jimmy in the back, causing him to be paralyzed.
Worst, the show made him out to be a bad guy, even though he was obviously ridiculed by the rest of the characters. After accidentally shooting himself dead, and shooting Jimmy, his one friend Toby disassociated himself with him.
It got a better example with Connor, who suffered from Aspergers. Once his violent outbursts were explained, even Ally stood up for him. In fact, the amount of suffering he got from the principal was made public, and got Shepard fired.
In Supernatural, the Winchester boys (Sam in particular) often had trouble fitting in due to having to move around so often. This led to a great deal of I Just Want to Be Normal on Sam's part that eventually caused him to have a falling out with his father. The fact that being called a freak is his Berserk Button is just icing on the cake.
The X-Files: Mulder is a loner, due to his crazy ideas about aliens and government conspiracy. He's a joke to the FBI and is mocked by his peers, nicknamed "Spooky" (however, that nickname originated as a sign of respect). He doesn't seem to mind too much, though. He doesn't go out of his way to make friends and likes to work alone; the first half of the first season is him just messing with Scully to try and annoy her enough to get her to leave. It doesn't work, and she ends up being his defender of sorts to others in the FBI. He has exactly four friends, including her, three of which are just as odd as he is. His loner tendency may stem back to his childhood, in which his parents emotionally abandoned him after the abduction of his sister. He noted that it "tore the family apart", and he is never seen to have a close relationship with his parents, who divorced soon after the incident.
Toyed with in Dark Oracle. Lance is an antisocial gaming geek, but is one of the main protagonists. His Cloud Cuckoo Lander girlfriend Sage is similarly weird and isolated, but a very pleasant girl. Vern, Blaze, and comic!Sage on the other hand, cross in Loners Are Freaks territory and stay there.
I'm not afraid now of the dark anymore And many mountains now are molehills Back in Berlin they're all well-fed I don't care People always bored me anyway
Harry Chapin's "Sniper". The titular sniper is described throughout the song as a strange loner, according to those who knew him. Deconstructed as, according to the sniper's thoughts, everyone treating him as a freak is what sent him on his rampage.
Suicidal Tendencies (the name is program) "Alone":
I scream at the sky, it's easier than crying I'm shyish when I'm shouting out loud I feel so alone in a room full of people I'm loudist when I'm in a crowd
The Bible has a few scriptures that concerns this trope:
In Genesis 2:18, the only thing that God declared something in His creation "not good" is that Adam is all alone, which He Himself says that "it's not good for man to be alone." And this is why God took a rib out of Adam and created Eve to keep him company.
One meaning of Proverbs 18:1 is that a person who separates themselves from others in seeking their own desires and aren't concerned about the needs of other people fit under this category.
Ecclesiastes 4:9-12 shows how two is better than one and things won't end well for those who do things alone.
In Unknown Armies, spending three days alone is the sample Rank 3 Isolation stress checks, while spending 7 days alone is the sample Rank 5 Isolation stress check. This means that the average character and average rolls will reach a permanent insanity from being alone, and beating the odds leaves said character more than a little weird.
In Genius The Transgression, Geniuses of high Obligation (Morality) might transgress just from avoiding people for too long.
Same with changelings, but that's because they have issues.
Kopaka: I Work Alone. Pohatu: What, by choice? Or just because nobody else can stand you?
The protagonists of so many video games, especially older ones (i.e. before the dawn of multiplayer), are fully portrayed as Loners Are Freaks...but this is also played as being a good thing, because no normal person, or even average soldier, could...
...fight a one-man war against Hell's armies, eventually killing the big bad daddy of all demons, whose death throes destroy Hell itself. (Doom)
...save the world from a cyborg-mutant overlord and his plans to turn humanity into a peaceful Hive Mind of long-lived, super-intelligent beings...that would then be unable to procreate, resulting in inevitable extinction within a matter of centuries. (Fallout, which placed a lot less emphasis on the party than Fallout 2)
...mop the floor with the remnants of the American government, blowing up their main base, Logic-bombing the freaking president, racking up a surreal kill count and casually blowing up cities with nuke launchers, either becoming the new Messiah or Satan's offspring. And above all, he is even named 'The Lone Wanderer' (Fallout 3)
The Lone Wanderer and the Courier are, in fact, the most lonesome of the Fallout protagonists. They are allowed a maximum head cap of 1 human and 1 non-human per "party". As opposed to the older games, which allowed you a reasonable 5 man team. Depending on how you play, you may end up wandering the lonely wastes with naught but your faithfulhound as your only company. Or with absolutely no company at all.
In fact, in the Lonesome Road DLC, the Courier can get a perk that makes him stronger if s/he goes off to face Ulysses by him/herself, aptly titled Lonesome Road.
Fallout loves this Trope. Fallout 1 makes the PC the person who is most adept to wander the "World Outside" in the first place and he/she ends up to be cast out by his superior. In Fallout 2 PC is descendant of the original PC who must be sent out to the Big World. In Fallout 3 you are child of a person who wasn't supposed to be there anyway. In New Vegas you are a courier, who was not meant to be there in the first place.
...destroy the entire pantheon of Greek gods. (God of War)
...aid the formation of the unlikeliest military alliance in, well, quite some time anyway, in order to battle back a demonic apocalypse. (Warcraft III)
...prevent dragons from destroying the world by devouring their souls and using their powers against them. (The Elder Scrolls V: Skyrim)
...escape a bizarre Death Course of a testing facility and destroy the homicidal AI running it. (Portal)
Weighted Companion Cube: "I thought we were friends... T^T "
The Enrichment Center reminds you that the Weighted Companion Cube will never threaten to stab you and, in fact, cannot speak. In the event that the Weighted Companion Cube does speak, the Enrichment Center urges you to disregard its advice.
...defeat the risen Count Dracula and his legions of monsters, earning the undying gratitude fear and hatred of the townsfolk. (Castlevania I)
...save the world three times over while stealing everything even slightly shiny and not nailed down and on fire (Thief).
Final Fantasies VII and VIII are stellar examples of the first, while Final Fantasy IX provides an example of the second (who lapses briefly into being the first type and is then snapped back out of it). Almost all of the other games in the series feature at least one brooding loner learning that he needs to come out of his shell and join the hero crowd.
Then Dissidia: Final Fantasy goes and turns the trope on its ear, setting Squall up in the same "brooding loner" role he occupied in his own game, only to then reveal that he chooses to travel alone because he believes in the Power of Trust and feels he can support the others from a distance. His explanation of his reasons is enough to convince the Warrior of Light... not that it prevents everyone else from continuing to pick on him about it, even after he ends up joining forces with Zidane and Bartz after all.
And Sho Minamimoto is the classic "evil (or at least crazy) loner that becomes an Ensemble Dark Horse".
In Mega Man Star Force this is the main subject in the first game. In the second game the theme was more like "fight for the friendship", which was just an extension of this trope.
Averted in Shin Megami Tensei III: Nocturne. Nocturne's protagonist and his scattered friends all start the game proper alone, each doing their own thing. Out of all of them, he's the only one who ends up more or less stable(depending on the player), even having the option of readily accepting a puzzle game challenge from a kid.
Nocturne deserves some expansion - see, there's even a whole philosophy of existence you can embrace to recreate the world, Musubi. Its leader, one of said friends, is not only a Hypocrite of the first order, but will mercilessly use you and mock you for your dedication to Musubi as he succumbs to madness. Another philosophy, Yosuga, is a Might Makes Right world - albeit one with serious paranoia complexes, in which you can never cease looking over your shoulder, never rest, never relax. Yosuga's leader, another of your friends, also goes insane. Both of them lose their marbles and will die whatever you do. When the option to just go into absolute Omnicidal Maniac mode and trigger a Z-Class Apocalypse How starts looking good, you gotta reconsider whether being alone is worth it.
Depending on your alignment in Shin Megami Tensei I, you'll have to kill at least one of your allies, and no matter what both the Law Hero and Chaos Hero will die by the end.
Played straight in Persona 4 with Mitsuo Kubo, a creepy Gonk who decided becoming a copycat murderer was the only way he could ever get attention. His own shadow represents the fact that his true pathetic self hides behind video games and that he's practically dead inside. After being defeated he is later sent to an asylum after the characters learn he wasn't the true murderer.
Continued in Platinum where the player encounters Cyrus's grandfather, who tells you about how his grandson snapped at a young age due to parental pressure. Grandpa himself is quite a loner, holed up in a cabin in an eternal sandstorm that you have to pull off an impressive bike trick to even get to.
Touhou features several characters noted for shunning most human (or monster) contact most of the time. How much they are portrayed as "freaks" for this varies widely, however.
Alice Margatroid, who lives in much the same situation as Marisa (even living in the same woods), however, is portrayed as an anti-social freak, or even a Stalker with a Crush of Marisa's.
Fujiwara no Mokou likewise isolates herself, apparently feeling more connection to humans than youkai society, she protects people who wander into the bamboo forest, but isolates herself from them otherwise, main reason being that she knows she will outliveeveryone she meets. Her Bifauxnen appearance, and Les Yay relationship with Keine prevent anyone from calling her a freak, however.
Kaguya Houraisan, Immortal Enemy of Mokou, however, in spite of living with a friend and servants, is portrayed as a NEET and fangirl.
Katawa Shoujo: Hanako's classmates see her as this, thinking of her as a strange hermit who never talks to anyone. Becoming closer to Hisao reveals this, but doesn't really make her less of a loner - she becomes less anxious, but still tells Hisao matter-of-factly that she doesn't really like most other people, and Hisao doesn't really press her on that.
In Lilly's route, however, Hanako becomes less of a loner, not only befriending Hisao, but also joining the newspaper club and spending her summer vacation on a trip with one of her classmates who is also in the club. Her teacher also notices that her attendance and grades have improved since becoming friends with Hisao.
Rin also counts, as she is a Cloud Cuckoolander with a talent for making vivid and disturbing art. She, like Hanako, has only one friend, but she's significantly less close to Emi than Hanako is to Lilly.
Archer of Fate/stay night chose to never share his ideal with others and simply went from one battle to the next, never seeking the praise or company of others. Because nobody understood why he would choose such a life, nobody trusted him or questioned it when he was made into a scapegoat for a war he had tried to stop.
MAG-ISA: This trope applies to a lot of the characters in the webcomic. Kyle, Alice, and Chu were loners in school. That is why they joined some crazy cult and shoot up a school.
No Rest for the Wicked: Red, who's Ax-Crazy, and the Witch, who's worse. At one point, Perrault suggests to November that they might want to leave Red: the years alone in the woods might have been what drove the Witch crazy, and Red might be well down the same path.
The Smurfs was sometimes accused of this, along with a number of children's shows accused of preaching conformity (ruthlessly parodied by the "Buddy Bears" on Garfield and Friends). Smurfs often got in trouble for either working independently from the others or ignoring their informed warnings, depending on who you asked. This is a milder version of where some people took it...
The Ice King. He rules the Ice Kingdom, which is uninhabited (except for snow creatures he creates occasionally, and penguins.) He gets a LITTLE better once he becomes friendlier with Finn and Jake.
Lemongrab. He's a science experiment gone wrong, and is socially awkward and isolated- and a huge jerk. Apparently, he prefers to be alone... not that anyone would really desire his company, anyway.
Prowl in Transformers Animated is considered a bit of a weirdo for how much of a loner he is. Despite technically being part of a team, he's always saying he'd rather work alone, or that he only depends on himself.
Which is zig-zagged six ways from Sunday throughout the course of the series. Jonny is acknowledged as the weird one of the neighborhood for obvious reasons, but at the same time he was usually quite friendly with the other kids, and participated in many of their activities (with the Eds being the outcasts as their own separate clique, on the outside looking in). Jonny was just more capable of having fun on his own (although the series also took an ambiguous stance on just how "imaginary" Plank was). This is then played completely straight at the very, very end of the series, where the Eds finally get accepted and Jonny becomes full-on outcast.
Deep Six in G.I. Joe became a deep sea diver solely so he could go on missions alone. He's never been known for being sociable, and all of his teammates are constantly suspicious of ulterior motives that he simply doesn't have.
It is often joked that Danny Phantom's nemesis Vlad Masters should get a lonely guy cat... which he does in Season 3. Considering who he is, he does qualify.
As Mark Evanier notes in the Dungeons & Dragons piece linked above, this was a common Aesop that consultants would foist on cartoons in the 1980s. One extreme example Evanier points to in the piece: The Get Along Gang, where this was the only Aesop.
Mentioned in Daria, especially "Boxing Daria", where the title character's parents have a fight over her lack of ability to get along in pre-school. (Daria herself managed to avoid this mostly by her friendship with Jane, and to a lesser extent Beavis and Butt-Head.)
Played straight and subverted in the first episode of My Little Pony: Friendship Is Magic. Twilight Sparkle, the main character, is seen this way by the denizens of Canterlot, but on the other hand, the overly friendly ponies of Ponyville strike Twilight Sparkle as rather crazy.
Loners barely even seem to exist in the show; friendship is, quite literally, one of the fundamental forces of that universe. The biggest loner so far shown is Zecora (a faux-African witch doctor living alone in the dark woods), and she's a very sympathetic character - the first episode featuring her is all about how she's not a freak. On the other hand, even she is not a complete loner, as she keeps friendly relations with the main characters, doesn't mind visits to her hut and sometimes helps out with celebrations in Ponyville.
One of the themes in "A Friend In Deed" is that some people just want to be left alone, and that's okay.
Mr Freeze from Batman: The Animated Series is another example: where Batman has Robin, who he treats as a teammate, Mr Freeze is completely ruthless when one of his henchmen gets accidentally frozen.
Gargoyles live in a clan structure, and gargoyles within a clan are very close and protective of each other. Losing her clan and being alone for centuries is part of what drove Demona to go from disliking humans to actively trying to wipe out the species.
Scottish comedian Billy Connolly talks of Fred West, a British serial killer. He mentions when the neighbours were questioned, they described him as a "loner", to which he replied "You bet your arse he was a loner! They seldom attract the fun crowd..." And later joked "Mind you, he was a hell of a gardener"; West was known for burying his victims in his back garden.
American comedian Christopher Titus also joked about this, remarking that "if you guys got a neighbor, being real cool, always saying "hi"... take him out!"
Jay Leno had a joke about this, something to the effect of "The neighbors always say that he was a quiet man and kept to himself. Just once I'd like to see a neighbor say 'He was an obnoxious jerk that always bothered everyone! I should have turned him in to the cops when he peed on my Oldsmobile!'"
In fact Fred West was married, with several children (some of whom he raped and murdered) and a home full of tenants (see above). He was the very opposite of a loner.
Seung-Hui Cho, the perpetrator of the Virginia Tech massacre, was described as a loner by many students. He would apparently spend some days just sitting in a wooden rocker staring out his window at nothing in particular and had stalked several female students. Even after being diagnosed as having selective mutism and other mental problems, the only help his parents sought for him was from churches who insisted that he was being "afflicted by demonic powers and needed deliverance".
Both Churches that have an established exorcism ritual (Catholic and Orthodox) virtually always have, as the first step, "see a psychologist and see if that helps". "Consult a physician" (psychology as a separate discipline being comparatively new) has been the first step in exorcisms since at least the time of Augustine—contrary to popular belief, the ancient and medieval worlds didn't automatically attribute all mental illness to demons.
This trope often comes up in media news to describe a perpetrator in a major shooting massacre. It's usually the first headline about the shooter whether it's actually true or not. With some justification, most people aren't immediately prepared to admit friendship with an accused killer.
According to some psychiatric researchers, there is are a number of 'personality disorders' such as 'avoidant personality disorder' and social anxiety that cause victims to be severe introverts. There is increased risk of other mental disorders, but these people are rarely dangerous. Sadly, these people are often mistaken for 'antisocial' individuals who can be harmful to society.
In the examples above, the person deep down still desires friendship and intimacy, they just have problems obtaining them. For natural loners, who really couldn't care less if they have any friends or not, the personality disorder is called schizoid. However there is controversy about it actually being a disorder, since those affected may not actually suffer in any way. One calls the disorder "the medicalization of non-conformity".
Also, antisocial personality disorder has nothing to do with socialization. A psychopath can have a rather active social life when he's not shoplifting or torturing people. They probably secretly look down on the people they know, but they are still sociable with and may even genuinely like them, if in a narcissistic way.
In a real-life inversion, crimes are more likely to be committed by extroverts, not introverts. The researchers who discovered this theorize that it doesn't have much to do with any relationship between morality and the desire to socialize—it's just that introverts have fewer social contacts in general, and crime, especially violent crime, is usually a social activity. If you're sitting at home and reading, you haven't got the opportunity to punch somebody out at a bar, right? Oddly enough, people with antisocial personality disorder are also often extroverts, despite the "dangerous loner" stereotype.
The 19th century poet Emily Dickinson, who gradually withdrew from human society and lived alone for the rest of her life, communicating with the outside world primarily through letters. There is no definite answer as to why she decided to become a recluse. Some of her poems appear to imply that everyone else thought her to be pretty weird for choosing to live alone in a house instead of getting married and pumping out babies like all the proper, decent girls were doing. (Going into seclusion was one of the very few alternatives to marriage and childbearing in Dickinson's era. Women who did so - and it was only really possible for women who had money of their own - were often considered little better than freaks of nature.)
"He was quiet; kept to himself a lot" tends to pop up a lot when news outlets interview relatives and colleagues of murderers and other psychologically driven criminals, no matter how social they actually were.
A man was accused of selling US secrets to Israel, and surprise surprise, his neighbor said that she hadn't noticed it before, but he was unsocial and weird.
The reason for this is that being sociable is the norm, especially for criminals, so people rarely consider it worth mentioning if the criminal in question had a lot of friends. However, if a criminal is asocial it is considered out of the ordinary and therefore news worthy.
A lot of this could be chalked up to Opinion Myopia on the part of law enforcement and the news media. Both of those fields are dominated by extroverts (which makes sense, since they both require plenty of social interaction), so naturally they might view introversion as abnormal and maybe dangerous.
Dane Cook has a joke about this trope in which he states he'll try to befriend the guy at work that people would find creepy with a chocolate bar. In return, he'll be spared from the latter's eventual homicidal rampage through the workspace.
*gasp* .. Thanks for the candy!
When the first reported instances of postal workers "Going Postal" came about, in one instance an employee survivor actually lived because she was the only person that was friendly to the killer. No candy was involved, though.
Thoroughly averted in this article by Jonathan Rauch.
Averted with some of the greatest killers in history, including Ed Gein, Ted Bundy, Andrei Chikatilo, and John Wayne Gacy. Those guys were anything but loners. And that Charlie Manson.
Ed Gein was actually a severely disturbed individual who almost perfectly fits this trope, while he was not entirely cut off from the outside world he spent the majority of his spare time alone at home crafting furnishings out of human body parts. JW Gacy and Ted Bundy on the other hand are complete aversions of this trope. Gacy was a self-made business man and active in both local politics and his community, while Bundy at one time volunteered as a suicide help-line operator.
We'd like to think that Dylan Klebold and Eric Harris were a pair of whacked-out loners who were part of a pseudo-gang called "The Trench-Coat Mafia" and maybe, just maybe, if someone reached out to them (somebody else), the tragedy at Columbine High could've been averted. It's so much easier to write off the mass murderers as lone freaks with no sense of community when the reality is that psychopathy can manifest in anybody... turns out that the pair were accepted and liked amongst their peers. In spite of this Harris was a stone-cold sociopath - he wasn't a loner and actually considered quite charismatic. Klebold however suffered from depression and Harris was one of his only friends. Harris was the one who was largely behind the killing, with Klebold mostly just following him. As it turns out, psychopathy and sociopathy generally mean said people are actually very very social, if only to avoid appearing 'different' and to better blend in. Thus they learn how to project the illusion of emotion and how to use emotion to manipulate people even if they never feel these emotions themselves.
The "Loners Are Freaks" mentality really rose after the Columbine shootings because of these assumptions about Klebold and Harris. It's particularly jarring in that schools were telling kids to reach out to others and to stop bullying, while at the same time encouraging the "Loners Are Freaks" mentality, often by citing introverted characteristics as "suspicious behavior".
Chris Rock talked about the killers at Columbine being described as loners despite being part of something they called "The Trenchcoat Mafia". "I saw their yearbook. There were six of them! I didn't have five friends in high school. I don't have five friends now."
For the record, they weren't actually members of the Trench-Coat Mafia. That was a just a little club that...didn't really do anything but wear trenchcoats, and most or all of the members of that group had graduated by the time the school shooting took place.
Cats Are Mean is a product of this, because domestic cats are by nature loners, especially in contrast to pack-minded dogs.
This is also why loners and cats often get along so well, and both tend to prefer each others company to that of obnoxious sociophiles.
Notably, domestic cats would more accurately be categorized as "social but solitary," meaning that while important things like hunting are typically done alone and territorial disputes are Serious Business, overall they're still quite capable of friendly interaction in neutral zones, and many feral cats live in colonies. Many loners act in a similar manner, preferring to work or spend much of their time alone, but quite willing to socialize so long as it's under circumstances that they feel comfortable doing so.
Tucson, AZ shooter Jared Lee Loughner who became increasingly withdrawn and mentally unstable after high school.
Presumably, this is the principle, in part, of the wingman, as opposed to going out on your own to pick up women.
Aurora, CO shooter James Holmes was described as "unsociable" by his apartment-mates and was undergoing psychiatric treatment prior to dropping out from the University of Colorado-Denver.
This attitude got a member of a certain sci-fi board arrested for the murder of his father with an ax, with the prosecution basically declaring that since he was an internet nerd and a loner, he had to be a mentally unstable and Ax-Crazy freak. Most of the board basically threw their support behind his innocence, with one member from the same country actually helping out in petitioning for a court appeal. It took a few years, but the appeal resulted in a complete acquittal, with the judge basically deciding that his initial conviction had been a sham thanks to the prosecution playing to stereotypes and the jury falling for it hook, line, and sinker.
And now, we have Adam Lanza, which was described as painfully shy, with no friends, and according to his brother was even diagnosed with Asperger's Syndrome, though this may be doubtful.
And it's not the first time that half-baked attempts have been made to link autism with psychopathic loners. Tasmanian spree shooter Martin Bryant was erroneously believed to be autistic, when in fact he had a sub-70 IQ which is the legal definition of mental retardation.
A fair number of UK crime cases in recent years have involved people diagnosed with Aspergers, a notable example being Gary Mc Kinnon. This has led to people believing people diagnosed with Aspergers are dangerous. Nevermind if said person has other undiagnosed issues.
Elliot Rodger is another tragic example. For months, he posted an increasingly insane series of YouTube videos note To the point that his parents called the police over them complaining about how lonely he was. Mere hours before a shooting rampage in Isla Vista, CA, he uploaded a final video and mailed a manifesto which explicitly laid out that being a loner motivated the massacre, alongside a coupling of A Man Is Not a Virgin and Entitled to Have You (due to women not giving him the time of day).