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.
- How to Train Your Dragon: The parental generation of Vikings all have Scottish accentsnote , but their children (including the protagonist) all have American accents. And then some of the other Vikings have English accents.
- In The Lion King, everyone in the royal lion family speaks with American accents except for Mufasa's treacherous brother Scar, who has a British accent provided by Jeremy Irons.
- In Shrek 2: King Harold and Queen Lillian both have British accents (and are played by British 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.
- 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.
- 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.
- 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.
- 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 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.
- 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.
- 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 an English accent (Liverpool) while his siblings have General American accents.
- Numbuh One and his dad from Codename: Kids Next Door have British accents, but his grandfather and uncle have American accents.
- 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 mansion, yet speaks with a flawless American accent despite saying that she never heard one until she was seven.
- Family Guy's Peter and Lois Griffin both speak with thick, Rhode Island accents, but none of their children do: the eldest use regular American accents, and the youngest is, of all things, an Evil Brit. 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.
- 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 autistic spectrum sometimes speak with foreign accents.