Superman's entire history says a lot about this trope. As has been well-documented, Superman did not originate as much of a "boy scout" (thus making it ironic when people say, "there's no room for a boy scout, this isn't 1938 anymore") and was distrusted by and distrustful of authorities, while his adventures pitted him against people abusing the downtrodden. During World War II, he moved into the role of "boy scout" and was often depicted as fighting enemy spies to the point where by the end of the decade, he was frequently depicted in front of the American flag, and so-forth. Then, of course, by the fifties, everything about him seemed to change to suit the atomic age, from his powers, to his ideals. This, however, didn't stop him from occasionally tackling common prejudices of the time in which he has to battle an Expy of the KKK who are threatening a Japanese boy.
Values dissonance began to haunt Superman by the end of the '60s as he had not reverted to his earlier, rebellious form, but remained a symbol of the establishment, despite the youth movement moving that way. Attempts at "modernizing" Superman were often scoffed at, and between the '70s and the '00s, Superman was often used as an example of the right and virtuous old-fashioned superhero for better or worse, though besides "I don't kill," they're rarely specific about what "morals" of his are supposed to be outdated. That's not to say Superman never had any high points during this period, they just tended to be more about the overall plot or spectacle. Lately, they seem to be trying to get away from this.
Many Superboynote Superman in his youth comics had the main character, Clark Kent, being subjected to corporal punishments, usually in the form of spanking, by his adoptive father, Jonathan. However, Jonathan discovers the hard way why he would be called Man of Steel, even with a spanking machine, which it too gets destroyed. One even has it in a school! Now, think about that for a moment considering corporal punishment of any kind in school... at least state ones, would not go well with today's view.
Many modern collections of Golden Age stories have taken steps to try removing content that would be deemed offensive. For instance, many of the Wonder Woman collections remove the painfully racist caricatures of black people, replacing them with more natural-looking black characters.
Wonder Woman from the Golden Age had a particular problem because her creator, William Marston, believed that dominance, submission, and a very bondage-oriented culture were all needed in today's world. Wonder Woman at one point extols the virtues of being a (consensual) slave. And while Marston had very progressive ideas about women's empowerment for his day, he also seemed to think that women were "naturally" prone to things like vanity and emotional outbursts.
J. Michael Straczynski's Marvel Comics maxiseries The Twelve contains an In-Universe example. Golden Age hero Dynamic Man sees a woman who's been mugged being chased by a black man. Upon grabbing the black man he finds out that this is the victim's husband. He instantly loses interest in helping either one. Likewise, when he helps out a bar that is being attacked, only to realize it's a gay bar, he disgustedly comments that this sort of thing should have been stopped a long time ago before flying away.
The whole series examines the dissonance between Golden Age heroes and the modern world they've found themselves in; while all of them suffer to a degree, Dynamic Man is a particularly ironic example given how he constantly stresses that he's "the Man of Tomorrow."
An in-story example occurs in Infinite Crisis, when '70s superhero Black Lightning meets modern black superhero Mr. Terrific. Terrific remarks that a black person actually calling himself "Black Lightning" is ridiculous. (He did wear a black-and-blue costume, and his lightning bolts are often depicted as literally black, but still.) Lightning replys that when he began his career he was "the only one of us out there" and wanted people to know that.
Tintin in the Congo has often been criticized as having racist and colonialist views, as well as several scenes of unnecessary violence against animals. Hergé said that he was portraying the naive views of the time. When the album was redrawn in 1946, Hergé removed several references to the fact that the Congo was at that time a Belgian colony. This failed to mollify critics. Because of its controversial subject matter, the album was previously only published as a facsimile black and white edition in English. However, a color English edition was finally published in September 2005, by Egmont Publishing, with a foreword explaining the historical context (a similar move had been employed for the 1983 translation of The Blue Lotus) and a collectors'-edition banner in red covering the main image over the front cover.
When the album was to be published in Scandinavia, the publishers objected to a scene on page 56 of the color album, where Tintin blows up a rhinoceros with a stick of dynamite. They asked the page to be redrawn, and Herge complied. Instead of blowing the animal to pieces, the rhino accidentally fires the gun of the sleeping Tintin, gets scared, and runs away. This page was also used in the English- and German-language translations.
When discussing racism in the Tintin comics series one should also mention the fact that Hergé was forced to redraw black characters in "Tintin in America" and "The Crab With The Golden Claws" and change them into Caucasian characters under pressure of American publishers. This happened way in the 1950s!
Hergés early albums were mostly drawn for fun, without much documentation. The Blue Lotus was the first story where Hergé actually did a lot of research. He had met a Chinese exchange student who told him a lot about Chinese culture and the Chinese-Japanese war that was going on back in 1934. This motivated Hergé to put more research into all of his stories. "The Blue Lotus" actually has a section where Tintin discusses various racist stereotypes about Chinese people to Chang, who laughs and says "people in your country must be crazy!" Hergé later lost contact with his Chinese friend and wrote arguably the most beautiful and touching album in the entire series, Tintin in Tibet, just to express how much he missed him. They finally met again two years before Hergé's death.
In his earliest appearances, Black Panther was often called "Jungle Man" by Hawkeye and Goliath. While the name was in reference to his beast motif, calling a black man that name would justifiably be considered highly offensive in the 21st century.
Quite a few people didn't think it was appropriate in the 20th Century.
UltimateCaptain America is another in-story example. In order to maintain his World War II origin story for stories in the 1970s and beyond, the original Cap was said to have been frozen in an iceberg and thawed out years later. The Ultimate version goes into depth about the kind of culture shock that would happen if a man, frozen in the 1940s, actually woke up in the 2000s.
Unfortunately, Ultimate Cap actually doesn't feature enough values dissonance. At one point, when talking about possibly surrendering, he asks insultingly if any one thinks that the A on his forehead stands for France. Cheese-Eating Surrender Monkeys is a modern stereotype and during WWII, Cap actually fought beside dozens of French resistance fighters who regularly gave their lives to complete a mission or save Cap.
The Actual Captain America proved this point only a few issues later, during Civil War, when he makes a rather more intelligent and eloquent speech about the bravery of the men and women he fought besides in occupied France.
In Ultimate Avengers, Cap was in custody of some French soldiers, who just happened to be mentioning how brave the French Resistance was. About a page later, Cap's free and kicking ass... whilst the soldiers are cringing, giving up without a fight. That's Mark Millar for you.note He licks goats, after all.
Nextwave Cap: Close your eyes, go back to Avengers Mansion, and make my dinner.
'60s-era Cap featured many similar views played straight, with Cap nudging his career-woman girlfriend Sharon Carter to resign from SHIELD so that she could be his wife; back then, that was pretty normal. Nowadays, it makes Steve look like a dick. As such, Steve is now far more progressive with his views (including bowing leadership to Wasp and serving alongside many female Avengers without questioning their abilities), and his relationship with Sharon is modernized into a Battle Couple with Sharon being the one who proposes to Steve.
The entire early run of Cap's stories from WWII fit this category, most especially the ones featuring villainous "Japs."
Similarly, in the '50s there was a run where Captain America and Bucky came back and fully embraced the idea of the Red Scare. This was later retconned to be a replacement Captain America and Bucky who went a bit paranoid after getting a bad batch of the Super-Soldier Serum.
Ultimately, the differences between original Captain America and "Ultimate" Captain America are a values dissonance between the comics industry of the 1940's and the modern day. At the time, the industry was all about big patriotism and sticking by your country in times of trouble because hey, it's your country. Nowadays, comics are more willing to stick it to the man. Thus original Cap attempted to symbolize everything best about America, while post-Silver Age Cap tries to fight everything that's worst about it.
Manolito's parents' quick willingness to use corporal punishment on their son is also quite cringeworthy. It's worth pointing out, though, that this is still shown in a very negative way.
Also, one strip shows that mentioning divorce during dinner is a big no-no.
Early X-Men comics have some inevitable casual sexism that can be jarring to the modern reader, all the males (including Xavier) spend much of their time making crude remarks about Jean Grey and in one early issue the maid is ill so it falls to Jean to make everyone dinner (nobody questions this, least of all Jean).
Similar to the treatment of Sue Storm throughout most of the early Fantastic Four stories. Even tales that tried to demonstrate her value to the team - like "A Visit to the Fantastic Four" in FF #11 - come out painfully sexist now (as for the old running gag with Namor... let's not even go there...).
One early issue showed the team training in the Danger Room, with the male members fighting a robot while Jean - who went into combat alongside the men all the time - practiced using her telekinesis to sew.
One very early issue showed that every male member of the team was lusting after Jean, even Professor Xavier, who believes the biggest obstacle to a romance between them is his wheelchair, not that he's her teacher and twice her age. This has almost never been mentioned since then.
This idea was played with in X-Statix Presents: Dead Girl, where the Golden Age heroine Miss America was portrayed as an unapologetic racist. Ironically, she ended up in a romantic relationship with Anarchist, a black superhero she had earlier hurled a vile slur at.
Miss America's racism was later used by artist Nick Dragotta as part of a justification for making the new Miss America a Latina. He pointed out the delicious irony behind making the successor of an out-of-touch bigot a woman of color.
The climax of an early Constantine story dealing with a serial killer who targets the hero involves the hero getting a gun. Given that the killer is a Knife Nut, the confrontation is a bit uneven. For a British audience, the pistol was presumably an unexpected and shocking twist. For any nation where pistols are perfectly legal and commonplace, this is both an Anti-Climax and a bit of a What an Idiot moment for Constantine who did not think to use a gun on many previous occasions.
Chick Tracts either stubbornly ignore it, or simply don't realize it in many tracts which contain outdated values (one example is in "The Little Bride", when the Christian Suzy insists that Mohammed was not a man of God because he married teenage girls and had slaves).
In the Gargoyles "Bad Guys" series, it's revealed that Dingo was raised by his stepfather, who showed visible shock when the teenaged Dingo came home with a mohawk. You'd think someone who'd kill his wife, lie to her son about it and raise said son to a life of crime would be more understanding.
Writer James Robinson talked about this when explaining some of the character changes in the New 52 reboot of the JSA. He pointed out that while the team's all-white, all-heterosexual (and mostly male) line-up was to be expected back in the Golden Age, there was no excuse for it remaining that way in 2012. To that end, he slotted in the black Mr. Terrific and the Latina Hawkgirl as founding members of the team, and made Alan Scott/Green Lantern an openly-gay man.
DC Comics trend of returning characters from the Legacy Character inheritors to the versions the writers grew up with has had the unintended consequence of removing/killing off dozens of minority characters from the DCU. Because back when they were reading, all the major heroes were white.
An odd version of this occurs with the Flash (Barry Allen). Barry was previously treated as something of an optimist and a good-natured fellow, with cheerful science lessons for the readers. In the decades since his death, this almost became Flanderization, with Barry being treated something close to a saint whose only flaw was spending too much time on heroics, showing up late on dates with his wife. The problem with his return? Barry was intended to be a nerd hero, so his day job was a police scientist. In the 1950s, nobody thought much of it. In 2010, CSI, profiling, and forensics investigations are the subject of nightly television drama, so Barry's happy attitude was jarring on a character who'd retroactively seen more death than the Joker.
Although there is such a thing as Gallows Humor; it's common for people in jobs like Barry's to develop strong (albeit often somewhat dark) senses of humor as a psychological defense mechanism to counteract the grime and misery they're confronted with on a day-by-day basis in their careers. This tends to not make it into said dramas because angst is generally more dramatic and makes those involved seem less insensitive.
And with an increasing number of more comedic elements in forensics shows (Autopsy Snack Time, just as an example), the modern reaction to this is ITSELF subject to this trope,.
The typical climax to many strips in British Comics like The Beano in the '70s would involve a child doing something naughty and being given, as some stories put it, 'six of the best' - in other words, being bent across Dad's knee and whacked on the bum with a large slipper. It can be pretty surprising to a younger reader (ie. a reader not old enough to remember the time when smacking wasn't controversial) to realize that not only was that considered a moralistic plot element, you were supposed to laugh. Of course, recent (for example, 1990s-present) comics don't do that.
Racial stereotypes, especially black and Chinese caricatures, were also pretty frequent in British Comics back in their early days although no strip with these sort of characters were particularly longlasting. Some racial caricatures appeared in British Comics as late as the 1980s.
Dave Gibbons recalls encountering this trope when writing Powerman for a Nigerian audience in the '70s. In particular, he had difficulty with the idea that a fat stomach indicated success and power rather than gluttony and greed.
In the Mortadelo y Filemón comics by Ibañez, most non-white characters are drawn and speak as typical wartime caricatures, complete with accents, which raises more than a few eyebrows in the present day. That said, Ibañez's black characters tended to be universally more competent or at least less suicidally stupid than the white protagonists, so maybe it was just him catering to the drawing style expected at the time.
In Mexico, long-running comic Memín Pingüín features a blackface as the main character. And over there it is not seen as offensive at all.note Mexico doesn't have much racial discrimination nowadays, since most of the discrimination there is more based in socioeconomic factors. Though, there has been times when Black Mexicans have been stopped at the streets by policemen due to them misidentifying them with illegal Cuban inmigrants, but that's a story for another day... However, in 2008, when the Mexican Postal Service announced they would publish a series of postal stamps with the image of Memín, many American civil rights groups noticed the character, and criticized both the stamps, the comics, and the Mexican society as a whole as being obscenely racist, to the point it caused a minor international incident between Mexico and the United States, while the Mexican postal service was more or less left wondering why they were making so much of a fuss since these stamps weren't really intended to them. Whether it was deliberately done by the postal service or not, the stamps were sold out within days, reignited interest in the comic, and the stamps were also found on auction sites being sold at many times its face value. And for the record, the comic actually called out on the U.S. segregation issues in the 1960's, and spoke very harshly against racism.
It doesn't help that the titular blackface character looks more like a monkey due to the artist's drawing style, and in fact some issues have other characters think he's a talking monkey.
Shortly after Supergirl's introduction, there's a Superman story in which (for typically contrived Silver Age reasons) he has to pretend to be engaged. So, he spends a good part of the story making kissy-face with the mysterious new superheroine Mighty Maid. At the end of the story it's revealed she's Supergirl in disguise, and thus Supes has been making out with his 15-year-old first cousin. (A later story makes it clear that this is not Kryptonian-Earth values dissonance; first cousins couldn't marry on Krypton.)
Fact Note: in most US states first cousins can legally marry, doesn't lessen the squick though.
Superdickery is something of a sub-trope of this, as the "humor" of the time now comes off as manipulative, abusive, and all-around in bad taste in these heavily-P.C. times.
One arc in Runaways has the kids travelling back 100 years to 1907. New character Klara Prast is depicted in a number of ways that are very different to the modern kids, notably her reaction to the lesbian relationship between Karolina and "Negress" Xavin (actually a shapeshifting alien, which is a whole different set of things). Not to mention Klara's rather squicky relationship with her middle-aged husband. Klara, for reference, is twelve.
Fortunately, Klara herself was somewhat displeased by the latter, and eventually got over the former a bit, after spending some time with Molly and her modern-day worldview.
Speaking of Xavin, s/he was a product of Marvel's reluctance (at the time) to put openly gay characters in a series that they had hoped to market towards teenagers, which is also why his/her first appearance created a pretense for the newly-outed Karolina being put on a spaceship, and why, after Xavin and Karolina returned, Xavin kept assuming a male form. If Marvel had tried imposing such rules in modern times, they'd probably be subject to the kind of public-relations nightmare that DC faced when it vetoed Batwoman's lesbian marriage in 2013.
Fortunately, in the latest reboot, the nickname "Pieface" showed up only on one occasion, and got the speaker pummeled shortly thereafter.
A Donald Duck comic from 1949 called "Voodoo Hoodoo" showed, in a flashback, Scrooge McDuck hiring thugs to chase stereotypically drawn Africans out of their village so he could take their land, causing a witch doctor to send a zombie after him. Most of the sympathy of the story is reserved for Bombie the Zombie (who has had to search for Scrooge for years) and Donald (who the Zombie is currently chasing, mistaking him for a young Scrooge), with relatively little for the African tribe. When later depicted in Don Rosa's The Life and Times of Scrooge McDuck, there is no doubt that his treatment of the natives is Scrooge's Face–Heel Turn, and arguably a crossing of the Moral Event Horizon.
The story Asterix and the Secret Weapon (La rose et la glaive) had a female bard, Bravura, come to the village, and introducing feminism to its women, which causes the men to leave the village in protest of their unfeminine ways. The main plot deals with female legionaries being introduced to fight the Gauls, because Gaulish gallantry insists they can't fight women. In the end, though the women of the village are prepared to fight, Asterix suggests they defeat the female legionaries by turning the village into a combination shopping center/spa, where the women can get mani/pedicures, get their hair done, and buy new clothes. In the end, the story ends with the men coming back and the women happily going back to their roles as housewives. Bizarrely, this comic was written in 1991, at a point where everyone should have known better. Even more bizarrely, most critical outrage was focused on a scene where Asterix punches Bravura, saying this would normalize violence against women, even though the context was completely different to domestic violence (it was in reaction to the second time Bravura had sexually harassed him publically, using her size difference to manhandle him and completely ignoring him asking her to stop - and he immediately felt horrible about hitting her, and almost all the other characters treat him like crap for the rest of the story as a result of what he did) and the comics rely on silly violent slapstick constantly.
The comic also frequently presents black characters in the stereotypical blackface fashion with inky black skin and huge, red lips (in the earliest issues they even had thick "African" accents, although this was fortunately dropped in later volumes and the English translations). Interestingly, they rarely act out negative stereotypes when they have larger roles, behaving like any other character.
A more cultural issue is the frequent use of gentle Alcohol-Induced Idiocy and "funny drunk" archetypes, which are considered innocent in France, acceptable but not particularly child-friendly in the UK, and a thoroughly Discredited Trope in America where heavy drinking is connected in the public consciousness primarily to alcoholism. This may have contributed to how the comics have repeatedly failed to break America.
The Outbursts of Everett True depict a man with a Hair-Trigger Temper beating up anyone who angers him (or simply yelling at them if they're female). While this isn't so bad (several victims are depicted as Asshole Victims who deserve their comeuppance) one strip features a woman laden with many packages from a shopping trip politely asking Everett to give up his seat for her, which he responds to by yelling at her and accusing her of being one of those women who "gives women's rights speeches". While this may have been acceptable in Edwardian times, nowadays it just comes off as rude and unchivalrous.
Newspaper Comics have fallen victim of this since the 1970's, with attempts to modernize strips by the syndicates not doing much to avoid getting them Deader Than Disco.
Zipi y Zape: A lot of stories show the twins receiving Corporal Punishment for their pranks. Keep in mind that most of that stories were written in the Spain of the 1940s and 1950s... Nowadays, YOU GO TO JAIL for this kind of punishments. The only reason the old comics still get away with this (sort of) these days is because it's always Played for Laughs.
Polish comic book Tytus, Romek i A'tomek was created when Poland was a Communist country under Russian control. In order to have the books published, the creator Henryk Chmielewski was forced to include elements of Communist propaganda in them as well have his heroes praising current system while being critical of much more western world.
In One particular story the heroes meet Fidel Castro who is shown as a very nice and sympathethic person...
Hob Gadling from The Sandman is another in-universe example. Being an immortal who has lived for centuries, he's done things in the past that were acceptable then but would be considered horrible in the present. He's especially ashamed of his past involvement in the slave trade.
Urbanus has lots of racial stereotyping (one of the characters is called "het Negerke", roughly translated as "The Little Negroid"). This makes export in other countries rather difficult, though the series is already too self-referential Flemish for that. The series did manage to be published in the politically correct Netherlands, though.
The infamous One More Day has this. The point of the story is that it's heroic to do whatever you can to save a life, which a fine moral... Except that "whatever you can" in this case involves making a deal with the devil, so the moral becomes "do WHATEVER YOU CAN to save a life."
There's also the reason behind using a deal with the devil to separate Spider-Man and Mary Jane; Joe Quesada wanted them broken up, but believed divorcing them would send a bad message and so used magic to remove the marriage from existence. For those who don't think divorce is a bad thing when you have suitable reason for it (which is a decent number of people nowadays), that makes the decision to use magic devil-deals ridiculous. Especially considering that most of Spider-Man's long-established supporting characters of roughly his own age-group were already divorced or widowed before One More Daynote Cleanly divorced: Randy Robertson (who is a few years younger than Peter Parker) from Amanda, and Debra from Mr. Whitman. Quasi-divorced (not married, but went through a very painful separation): Flash Thompson and Sha Shan. Widowed: Betty Brant Leeds (but not before her husband walked out on her because of her (second!) adulterous affair with Flash) and Liz Allan Osborn. To cap it all off, the issue immediately following One More Day revealed that Harry Osborn was alive and now a triple divorcé, having apparently married two more women after getting a divorce from his former widow Liz.
The follow-up arc, One Moment in Time, compounded this by motivating Mary Jane's decision not to get married to Peter in the altered-by-Mephisto timeline by having her say that she could not envisage raising children with Spider-Man and that marriage without children was meaningless. Which of course is not just out of touch with Mary Jane's established characterization, e. g. her joyful reaction to her pregnancy during the Clone Saga, but also with most readers' ideas about love and marriage.
Ever since it became popularized during the 2000s (with stuff such as De Kiekeboes) Fanservice shows up quite frequently in Franco-Belgian comic books that are targeted towards children (the best example of observing this phenomenon probably has to be Le Petit Spirou). This can be quite jarring in countries such as in the United States where this is considered inappropriate for the target audience, but is usually seen as quite acceptable in the BENELUX and France, where kids frequently show up as Dirty Kids in media, although it has been quite jarring for plenty of immigrants in those countries as well.
Jommeke can be this towards lots of people who grew up with comics that were not Belgian Comics (be it the American, Japanese or French type) due to how heavily it avoids having even the lightest mature subject matter (such as action, black comedy, flaws about school life, growing up, death, the environment, economy etc.) and thus ends up looking for the plenty who grew up with those comics as material that is so saccharinethat they would not even give it to their kids for a reading. Fact is that its heritage dates back from the '50s when there was a genre of Belgian comic books in which everyday families did everyday stuff. Before Jef Nys even worked on Jommeke he even created a comic book with an edgy kid character whose edginess stems from the fact that at times he would be a jerk. In its native Flanders the comic series does have a very long-lasting demographic and is even popular with Muslim immigrants, something that you do not expect from something that originated in a Catholic magazine. That here being said all of those facts also allow it to avoid Unfortunate Implications.
De Kiekeboes: Album #125 Vrouwen komen van Mars (women are from Mars) has in-universe Values Dissonance when the main characters travel to an album so old that it has become a holy grail among comic book collectors called De avonturen van snijboon en zoon through a machine that transports them there.
There is no female character in the entire album. At the end of the story it is revealed that the creator wanted his characters to search for womankind in the album Vrouwen komen van Mars but it was never finished due to Author Existence Failure.
There's a bit of discussion on Tumblr and 4chan's /co/ boards on how Harvey Comics' "Little Lotta" character, whose entire personality is more or less "hahaha, she's so fat", will never get an animated adaptation due to how relevant body-shaming and self-image issues have become.
In Watchmen, the first Silk Spectre not only forgiving The Comedian for trying to rape her, but having at least one consensual encounter with him later in life that resulted in her daughter's birth, can come across as awkward to modern readers. The Comedian in general, who in addition to the attempted rape was also a war criminal and multiple murderer, would likely be portrayed not nearly as sympathetically were he created today.