This trope arises when two or more members of the same family have noticeably different accents, despite living in the same household during the years that would have shaped their speech patterns. This trope only applies to cases where family members should logically speak with the same accent, such as a case of siblings who were raised by the same parents in the same environment inexplicably having different speech patterns or a child having a differing accent that doesn't logically derive from either of their parents. Situations involving Immigrant Parents are excluded, as children can and do pick up their parents' accents despite not speaking the language that created the accent or never having visited the country where the native language is spoken. Younger children also may pick up the accent prevalent in their new home rather than their parents' speech pattern, leaving them with a very different speech pattern than the family members who raised them.
If the trope goes entirely unexplained, it may have been an attempt to make a character more relatable to the target audience, but could be the result of an actor is Not Even Bothering with the Accent. It's also common for all accents from the same foreign country to be lumped together - if a pair of siblings in an American series are French, then it's likely that their actors will use (real or fake) French accents, but there's little guarantee that their accents will be from the same part of France.
A sub-trope of Unexplained Accent and Misplaced Accent. Compare The Kids Are American, where the adults have appropriate accents for their country of origin, but their children inexplicably have American accents.
- Yu-Gi-Oh!: Zigfried has a noticeable accent, but his younger brother Leon, doesn't.
- How to Train Your Dragon: The parental generation of Vikings all have Scottish accents,note but their children (including the protagonist) all have American accents. And then some of the other Vikings have English accents.
- In The Lion King (1994), everyone in the royal lion family speaks with American accents except for Mufasa's treacherous brother Scar, who has an English accent provided by Jeremy Irons.
- In The Prince of Egypt, the Egyptian royal family (except the high priests) have British accents while Moses, who was adopted, speaks in an American accent.
- In Shrek 2: King Harold and Queen Lillian both have English accents (and are played by English actors) but their daughter Fiona has an American accent. She's also married to someone with a Scottish accent.
- In Chitty Chitty Bang Bang Caracatus' father and children have English accents, but he has an American one. Of course this is because Dick Van Dyke's attempt at an English accent in Mary Poppins failed to go over well and they didn't want to repeat it, but it does raise questions.
- Repo! The Genetic Opera: Parvi Largo speaks with a pronounced Italian accent that nobody else in his family speaks with.
- The Phantom Menace: Anakin Skywalker has an American accent. His mother, Shmi, has a Swedish accent, or whatever the space equivalent is.
- Toys: Leland Zevo speaks with Michael Gambon's British accent even though the rest of the Zevo family are American and sound like it. The handwave is that his father was stationed in Britain when Leland was growing up and he got stuck with the accent.
Leland: Yes, I went to see a dialect coach, and the best I could do was [indistinct drawl] "You men stand over there, on my notation, until further notice." [British] They didn't buy it!
- Angel: Connor speaks with an American accent, which is odd as that accent doesn't exist where he was raised. His adoptive father Holtz is a Brit.
- Sheldon Cooper of The Big Bang Theory affects an East-Atlantic accent despite being from Texas, while the rest of his family have Texan drawls (although he does slip from time to time). This extends to the spin-off Young Sheldon, where he's nine years old. Narration from the pilot episode of that series explains that he chose to change his accent to sound smarter. Ironically, his sister, Missy, does not have a Texas drawl in Young Sheldon even though she had one in Big Bang.
- On Chilling Adventures of Sabrina, Hilda speaks with an English accent while her sister Zelda speaks with an American accent, even though it's implied they grew up together in the United States.
- In Quantico, Alex Parrish has a noticeable Indian accent despite having been born in the US and having an American father. Supposedly, she picked up the accent from spending several years living in India.
- Roseanne: The titular character and her husband Dan have a southern accent, but this doesn't apply to their three children.
- In Shadowhunters, character Izzy is played by actress Emeraude Toubia, who is the daughter of a Mexican mother and a Lebanese-American father. Because of this, the character speaks with a very noticeable accent not shared by any other members of her on-screen family.
- Sons of Anarchy: Despite supposedly having lived in California his whole life, main character Jax Teller has a different accent than the rest of his family due to being portrayed by British actor Charlie Hunnam.
- In Star Trek: The Next Generation, Deanna Troi has a heavy Eastern-European accent. Her mother has a more American accent.note
- In Supernatural, Dean often slips into a southern accent (as is natural for his Texas-born actor) despite moving around frequently as a child. His brother, Sam, doesn't speak with an accent.
- Reba: The show is set in Texas, but only Reba, Brock and Barbara Jean have accents appropriate for that area. Their children do not.
- Discussed in Cabin Pressure. Arthur claims his Australian father Gordon is the reason his Australian accent is so good. (It isn't.)
Douglas: Two things, Arthur: Australian accents arent genetic; and you cant do one.
- Invoked in a later episode: Douglas is impersonating Gordon and speaks in an Australian accent. Arthur, ever helpful, tries to do an Australian accent as well, despite having spoken earlier in his normal British accent. Douglas quickly explains that Arthur "likes to tease his old dad."
- Overwatch: The characters of Fareeha "Pharah" Amari and Brigitte Lindholm are the daughters of other playable characters Ana Amari and Torbjorn Lindholm respectively. However, Pharah and Torbjorn are voiced by Americans performing accents that may not be the most convincing. Ana and Brigitte, however, are voiced by people from the character's country of origin and thus sound much more authentic.
- inFAMOUS: Dr. Sebastian Wolfe in inFAMOUS 2 speaks with an English accent, but his brother Raymond—who appears in inFAMOUS Second Son—speaks with an American accent in addition to looking at least twenty years younger than Sebastian.
- The Oats Series: Older Pig speaks with an American accent while Younger Pig (and just about everyone else they know) speaks with a British accent.
- In Animaniacs, Wakko Warner has a Liverpudlian accent while his siblings have New York accents.
- Numbuh One and his dad from Codename: Kids Next Door have British accents, but his grandfather and uncle have American accents.
- out of universe, this can be explained by these characters being revealed as relatives in later seasons, being a big twist that probably wasnt the original intention.
- The title character of Dexter's Laboratory has a vaguely Eastern-European accent despite the rest of his family having American accents.
- Webby of DuckTales (2017) was raised by her British grandmother in a Scottish trillionaire's mansion and claims to have never heard an American accent until she was seven. Her natural accent is completely American.
- Family Guy's Peter and Lois Griffin both speak with thick Rhode Island accents, but none of their children do: Meg and Chris sound like they're from Southern California while Stewie sounds like he's from the city of Westminster. Even when he finally outs himself as a Fake Brit, the trope still applies, as his accent is no different from his siblings.
- Futurama: Amy speaks with a Valley Girl-kind of American accent with some Future Slang, while her parents have noticeable Chinese accents. It clearly resembles a family where the parents are immigrants, but all three were born and raised on the same colony of Mars, and the (non-native) culture there isn't recognizably different than in New New York.
- Neither Rarity nor Sweetie Belle of My Little Pony: Friendship Is Magic share their parents' heavy Upper Midwest accents. Sweetie Belle speaks with a fairly general Canadian-American accent, while Rarity has affected a Mid-Atlantic accent, though it occasionally slips into something closer to her sister's accent than her parents'.
- Star in Star vs. the Forces of Evil has a general American accent, even though her parents (along with the rest of Mewni) both speak with English accents.
- Teenage Mutant Ninja Turtles: The Turtles, growing up in New York City, all have American accents though they were raised by a Japanese immigrant. However they all have wildly different American accents suggesting they may have been raised as much by TV. Usually only Raph sounds stereotypically New York, Mike is somewhere in southern California, and Leo and Don are more neutral/midwest.
- Voltron: Legendary Defender: In a flashback, Keith's father is seen. He speaks with a heavy southern accent, but the son he raised mostly alone doesn't have one. This spawned the theory that Keith is Texan, and since his father has yet to receive an official name, gave him the Fan Nickname "Texas Kogane".
- Children on the autism spectrum have been known to speak with foreign (or foreign-ish) accents.