History BigBrotherInstinct / Film

* ''Film/Aquaman2018'': Defied. Arthur was originally overjoyed to find out that he had a little (half-) brother, and wanted to try to be a brother to him after their mother died. However, when he found out that his brother was a warmongering racist and "... kind of a dick", their relationship quickly soured. [[spoiler: The end of the film teases that the brothers may reconcile, so...]]

* Franchise/MarvelCinematicUniverse:
** Switches back and forth between Thor and Loki [[Film/{{Thor}} depending]] [[Film/ThorTheDarkWorld on]] [[Film/ThorRagnarok the]] [[Film/AvengersInfinityWar film]]:
*** Zig-zagged in ''Film/{{The Avengers|2012}}'', when Thor begins to defend Loki but thinks twice after hearing how many people Loki has killed:
---->'''Bruce:''' I don't think we should be focusing on Loki. That guy's brain is a bag full of cats. You can smell crazy on him.\\
'''Thor:''' Have care how you speak! Loki is beyond reason, but he is of Asgard and he's my brother.\\
'''Natasha:''' He killed eighty people in two days.\\
'''Thor:''' He's adopted.
*** The most prominent example appears in ''[[Film/AvengersInfinityWar Infinity War]]'' when Loki hands over the Space Stone to protect Thor from Thanos, and is then [[spoiler: murdered for his efforts]]. [[HeartbrokenBadass Heartbroken and nearing a total breakdown]], Thor goes on a RoaringRampageOfRevenge against the Mad Titan to deal with his guilt and despair.
** Like in the comics, [[ComicBook/{{Quicksilver}} Pietro Maximoff]] acts as this for his twin sister [[ComicBook/ScarletWitch Wanda]] in ''Film/AvengersAgeOfUltron''. The minute she is taken out by Hawkeye, he carries her off to safety and furiously promises to murder him for her sake.
** ''[[Film/BlackPanther2018 Black Panther]]'' -- insult or threaten T'Challa's sister Shuri, and you are ''guaranteed'' to get your ass kicked... as Killmonger discovered the hard way.
** In ''[[Film/AvengersInfinityWar Infinity War]]'', Gamora reveals the [[spoiler: Soul Stone's location]] to Thanos to stop him from torturing her sister Nebula.
** [[spoiler: Nebula returns the favour in ''Film/AvengersEndgame'' as when her [[IHatePastMe evil past self]] aims her gun at Gamora, Nebula shoots herself down without hesitation]].
** The opening flashback of ''Film/BlackWidow2021'' shows that Natasha Romanoff was extremely protective of her "younger sister" Yelena Belova. When their mission to pose as an American family ended Natasha, who was ''[[LittleMissBadass eleven years old]]'', grabbed a gun off one of the soldiers that came to separate them and threatened to shoot if they tried to put Yelena in the Red Room again. When they reunite as adults Natasha's protective instincts kick in again and she's seen telling Yelena to put a seatbelt on during a car chase.
** In ''Film/SpiderManNoWayHome'', [[spoiler: the [[Film/SpiderManTrilogy Raimi]] and [[Film/TheAmazingSpiderMan Webbverse]] Spider-Men display this to their younger AlternativeSelf from the MCU as well as Ned and MJ (the latter of whom Webbverse Peter saves from falling). The older Peters do their best to impart what they've learned to MCU Peter and look out for him, with the Raimi Spidey personally stepping in to prevent his young counterpart from killing the Green Goblin in revenge for Aunt May. Webbverse Spidey even touchingly admits he always wanted brothers as an only child.]]

* ''Film/XMenFilmSeries'':
** ''Film/XMenOriginsWolverine'':
*** For all his (many) flaws, Victor Creed really loves his little brother Jimmy. It's best illustrated in the Civil War part of the opening montage, when Logan is shot and they are (at the time) unaware of their healing factors, Victor's expression says it all.
*** Kayla appears to be willing to do anything to keep her sister safe.
** ''Film/XMenFirstClass'':
*** Charles had this for Raven, being very concerned for hiding her mutant form in public and telling her directly that he didn't want anything to happen to her. However, his relationship with his foster sister [[{{Deconstruction}} deconstructs]] this phenomenon because it caused him to become [[MyBelovedSmother overprotective]] to the point where he denied her the chance to embrace her true appearance and be proud of what she was, as well as caused him to [[ObliviousToLove ignore her very obvious crush on him]]. This in turn made Raven turn to Erik as a mentor/love interest and eventually join him in his cause against humanity.
*** Darwin develops this for the younger mutant recruits, especially when Shaw attacked the CIA base. Unfortunately, [[spoiler:this only gets him killed by Shaw when he tries to protect Angel from him.]]
*** By the time of the Cuban Missile Crisis, Erik had already begun to view Charles as a brother figure. When the Blackbird spiraled out of control, Magneto used his body to shield Xavier from injury, and he [[spoiler:''immediately'' halted his attack on the American and Soviet naval forces when Charles was shot.]]
** ''Film/XMenDaysOfFuturePast'':
*** When the younger Charles sees Mystique again for the first time in 11 years, he caresses her hair and shoulder as a gesture of comfort while telling her that he will keep her safe among other soothing words. [[spoiler:When Magneto then points a gun in her direction]], Xavier stands in between the barrel and his foster sister, and [[spoiler:Erik later has to use his power to change the bullet's trajectory so that it won't hit Charles in the head]]. Despite their estrangement, Xavier is willing to die for Raven to save her life.
*** Peter Maximoff is seen playing with his little sister. He's even willing to sit down and watch television with her, which is heartwarming considering how hyperactive the guy is.
** ''Film/XMenApocalypse'':
*** Alex Summers brings Scott to Xavier's school in the hope that his former mentor can help his younger brother cope with his potentially dangerous mutant power.
*** When Apocalypse is asphyxiating Mystique, Charles doesn't even think twice before he expresses his willingness to surrender himself, but then Moira reminds him that he can't do this because the entire planet would then fall under Apocalypse's control. Xavier collapses in tears when he realizes that he can't exchange his life for his foster sister's.
*** Beast behaves this way towards Cyclops. He designs a means to help the young man see without vaporizing everything. During the final battle, the two are constantly by each other's side, which is especially poignant considering [[spoiler:Scott's actual older brother and Hank's former teammate Alex had died earlier]].
*** [[spoiler:Once Magneto pulls a HeelFaceTurn, he stretches his powers to their limits, doing everything he can in order to protect Charles, whom he loves like a brother, from Apocalypse.]]
* ''Film/{{Zathura}}'': Walter originally acts [[AloofBigBrother aloof]] and is somewhat a [[BigBrotherBully bully]] towards his younger brother, Danny, such that the astronaut whom they meet call him out on this. Then it's revealed that [[spoiler: the astronaut is in fact Walter all grown up who angrily used his wishing star to wish that Danny would disappear, which he has thoroughly regretted because that means he is stuck in space forever. He then tries to [[TheAtoner atone]] for this by going to the past and influencing Walter to start treating Danny as more than a plaything]]. Once he learns about this, Walter softens and becomes genuinely caring to Danny.
** Their older sister, Lisa, is this too, to a lesser extent. Contrasting with her aloofness and obliviousness to the situation, the bit where [[spoiler: she's pulling Walter away to safety from the titular Zathura in exchange for getting sucked herself]] near the end of the film is kind of sweet.

* ''Film/TheBlindSide'': [[spoiler:With only a split second to act, Michael instinctively saves adoptive little brother SJ from being seriously injured or killed during their car accident.]]
** He also will '''not''' [[KnightTemplarBigBrother tolerate anyone saying something derogatory about his adoptive little sister, Collins]].

* In ''Film/ResidentEvilAfterlife'', Chris Redfield is this to his younger sister Claire.

* ''Film/TheHollowChild'': Samantha sees her younger foster sister Olivia as more [[AnnoyingYoungerSibling annoying than anything else]] initially. Once she disappears in the woods then returns in a form Sam recognizes as not really her, she sets out to get her back. No adults will [[TheCassandra believe]] and [[AdultsAreUseless aid Sam]], so it's left to her. Sam greatly risks her own life doing this, but [[spoiler:saves Olivia in the end, with the film closes on her saying she'll always be there to protect her]]. Sam had lost her own biological sister earlier, with obvious guilt over not being able to help, so this serves as a way that she makes up for it.

* ''Film/FreshmanYear'': Marchella's brother is initially very hostile to CJ after he gets her pregnant, thinking he'd just used her for sex, but relents after seeing that isn't so.

* Seen in ''Film/{{West Side Story|1961}}'' when Bernardo interferes in his sister Maria's budding romance with Tony. DoubleSubverted in that Tony is the only decent member of the Jets, genuinely in love with Maria and with good intentions... but then he ends up killing Bernardo in a fit of rage over the death of his friend.
* In ''Film/WhiteFrog'', Chaz once beat up a kid who peed on Nick's shoes in third grade.

** In ''Film/SpiderManNoWayHome'' [[spoiler: the [[Film/SpiderManTrilogy Raimi]] and [[Film/TheAmazingSpiderMan Webbverse]] Spider-Men display this to their younger AlternativeSelf from the MCU as well as Ned and MJ (the latter of whom Webbverse Peter saves from falling). The older Peters do their best to impart what they’ve learned to MCU Peter and look out for him, with the Raimi Spidey personally stepping in to prevent his young counterpart from killing the Green Goblin in revenge for Aunt May, Webbverse Spidey even admits touchingly he always wanted brothers as a only child.]]