I Have Brothers

The tendency of female characters displaying skills in something that is traditionally viewed as being more of a male thing to explain it as being the result of having a number of (usually older) brothers. Can have a certain degree of Unfortunate Implications since it can be viewed as the writers saying that the only explanation for female competence (in traditionally 'manly' areas at least) is that she grew up imitating males.

Occasionally there is gender reversal (that could be viewed as being equally sexist) with a male character explaining his ability in stereotypically feminine areas such as cooking as being the result of having sisters.

Advertising

 * Not a practical skill, so much as an ability to sympathize: In one car commercial, a father notices his daughter is feeling left out of her brothers' games. He cheers her up by telling her how he'd grown up outnumbered by four sisters.

Anime and Manga
"Alto: Mmm? [My family comprises of my] elder brother, elder brother, me and my little brother. Lucino: That's it then! Alto: Eh? Eh? Lucino: Perhaps it is due to this family situation that is why, before the age of seven, you thought that you were a boy! Alto: Ah! How did you know that!?"
 * Extreme variation in the second sound stage of Magical Girl Lyrical Nanoha's third season while Alto and Lucino discuss their families:


 * Touma Minami is the resident Bifauxnen and Bokukko in Minami-ke. Guess how many Aloof Big Brothers it took to make her thus?
 * Bokukko Hikaru from Magic Knight Rayearth has three older brothers, who work at their dad's kendo dojo. She's real good with a sword, too.
 * This trope and its genderflipped version form the plot of the short manga You're My Girlfriend: The female lead grew up surrounded by older brothers, whereas the male lead was more-or-less groomed by his older sisters.
 * Gender-flipped in Gundam Wing, where Quatre's family consists of his father and thirty-nine sisters, possibly explaining his gentle nature. Of course, if you lived with 39 women, you'd learn to put the seat down real quick, too.
 * In Digimon Xros Wars, Akari says that she's always playing shooting games with her brother, to explain how she managed to destroy a fleet of living aircraft carriers with missiles from a boarded craft.

Film

 * In My Cousin Vinny, this was how Vinny's fianceé, a hairdresser, knew so much about cars. She grew watching her father and brothers do car repairs, and helped out as well.
 * The reason Cameron Diaz's character in the Charlie's Angels movie is so tough is because she has 5 older brothers who are in law enforcement/special forces/the FBI/etc.
 * Subverted in Atlantis: The Lost Empire where the young Wrench Wench Audrey said that she became a mechanic because she did not have any brothers and someone had to follow their father in the family business. Her sister became a boxer.
 * In the film Race to Witch Mountain, the female alien expert beats up a soldier and then offers this explanation.
 * In the Police Academy movies, Tackleberry's new girlfriend is as tough as he is, because her brother and father 'joke around' by hitting each other as hard as they can.
 * "My brothers play hockey. For the Rangers."
 * This is why Vivian from Pretty Woman knows so much about cars.

Live Action Television

 * Daphne Moon on Frasier: "You don't grow up with eight brothers and not learn a thing or two about engines. Or the importance of being first in the shower."
 * There was a pretty good example of this one in a Drake and Josh episode, aptly named Girl Power. Drake's "Date of the Week" scares off some bullying jocks by throwing one of them into a table, and when asked about it, she replies, "I grew up with five older brothers. It was either learn how to fight or get held down and burped on."
 * Parodied on Little Britain, where Emily Howard (a lady!) is walking past and a man, seeing as it's incredibly obvious that Emily's a man, calls "her" over to ask if "she" can fix his van. Emily insists she can't fix it as it's not a very lady-ish thing to do, but she eventually caves in and explains what's wrong in great detail, fixing it entirely. Her justification? "Growing up with four brothers, I was always going to be a bit of a tomboy!"
 * Played somewhat straight, but with an added dimension, on Eureka: kick-ass ex-Army Ranger Deputy Jo Lupo is all about such "manly" things as guns and beating people up (and only reads girly magazines when she thinks no one's looking). They didn't trot out the brothers excuse until the second season episode "Noche de Suenos," when she confessed that she used to want to be a dancer, but growing up with no mother and three brothers, she had to "learn to survive" and gave up on the dancing thing.
 * A one-off character on House, interviewing for an open position on House's team, explains why she hasn't stormed out offended: "I have four brothers. Keep your hands to yourself, and I can take anything that comes out of your mouth."
 * In the Law and Order episode "Girlfriends," Rey Curtis recognizes an item of lingerie as "the same label Madonna wears," explaining that he "lives with four women."
 * One of Echo's imprints in Dollhouse who was not intended for combat showed off gun skills and explained them by saying she had "four brothers, none of them Democrats".
 * Full House: Becky takes over for Jesse announcing a charity hockey game. Noticing Jesse's surprise that she knows what she's doing (which he certainly didn't), she mentions growing up with "5 hockey-crazed brothers."

Literature
""The gods," Chartiphon explained, "did not give our Prince a son ... so our little Rylla must be as a son to her father.""
 * Ginny's Quidditch skills in Harry Potter are explained this way, although her brothers were equally surprised.
 * It helps that all of her brothers are completely Quidditch-obsessed in only the way Brits who've never heard of football can be.
 * In the final book Harry notes that having six older brothers probably explains Ginny's toughness.
 * In Lois McMaster Bujold's Barrayar this is how Droushnakovi acquired the skill and ambition to become (apparently) the only female bodyguard on the planet.
 * Deliberately subverted in A Song of Ice and Fire. Sansa and Arya both have two older brothers and two younger brothers, but while Arya goes the tomboy route, Sansa is hopeless at anything she doesn't think of as "ladylike". Arya's fire is because she's supposed to take after her father (or, more accurately, her late aunt) than Sansa, who greatly resembles her mother.
 * Scarlet, in the GI Joe comic books, learned to be so good at martial arts because of her five older brothers. Who were all instructors at her father's karate school.
 * In Terry Pratchett's Equal Rites - "It was true that the girl spent more time climbing trees and running around shouting than little girls normally did, but a girl with four older brothers still at home can be excused a lot of things."
 * Slight variation in Monstrous Regiment, where Polly gets her ability to imitate boys from her family's owning a pub.
 * Not a skill, but Juliet in Unseen Academicals dismisses Glenda's dismay that she knows what tonkers look like by reminding her friend that she's seen her brothers bathing.
 * Beka Cooper's friend Ersken once comments that a man flirting with Beka is good looking. Paraphrased - "Don't look at me, Beka. Well, do look at me, but not like that. I have four sisters. If I didn't know what made mots(girls) curl their toes, I'd have to have had my head in the river for seventeen years."
 * In Meg Cabot's mediator series, Jesse helps Suze bandage her blisters from new shoes (the walking home on asphalt in a California heat wave probably didn't help either). When she askes how he knows what to do, his response is (paraphrased): "I grew up with three sisters. I know a thing or two about new shoes."
 * Subverted in Lord Kalvan of Otherwhen with Princess Rylla, blonde, beautiful, and a hard-riding cavalry officer who loads her pistols with a heavier-than-usual charge:


 * Parodied (and taken Up to Eleven) in the Dear Dumb Diary books. "She has brothers" is basically Jamie's excuse for why her best friend is an Ax Crazy Manipulative Bastard.
 * Specifically, Isabella has "mean older brothers". In over a dozen books, the actual evidence presented in this direction is: 1) Said brothers may have once lined up and farted in Jamie's direction, and 2) one brother has a room so filthy and personal habits so unhygienic that the sight demands Brain Bleach in multiple females. The evidence that Isabella is a pure sociopath is much greater, and continual.
 * Subverted in the Mercy Thompson series, in that Mercy attributes her assertiveness (and how!) to the fact that she grew up with werewolves, not the fact that most of them were male. Also, her skills as an auto mechanic come from being trained by a fae later in her youth, not from a childhood among males.
 * The Animorphs series gives us Estrid, an Andalite theoretical physicist who happens to be very, very good at tail-fighting, because she learned from her brother - a renowned exhibition fighter. Unusual in that her gender isn't the (main) reason for Ax's surprise, her lack of combat experience (and the sheer skill she exhibits) is.

Video Games

 * Also Louie's mother's ability at baseball in Life With Louie.
 * A rare male example with brothers, the Scout in Team Fortress 2 gained his speed from being the youngest of eight brothers: It was the only way he could get to a fight before the others beat everybody up first!
 * According to Resident Evil: The Darkside Chronicles, Claire Redfield's brother did give her some basic training.
 * In Tokimeki Memorial 4, Itsuki Maeda lives within a family made only of men (father and brothers), who are all mechanics. As such, she has skills and hobbies percieved as masculine such as playing soccer, and being able to fiddle motorbikes and cars. That doesn't prevent her for having a cute feminine side, though.

Web Comics

 * Breya from Schlock Mercenary uses this to justify beating her black-belt martial arts instructor. Kevyn then uses "I'm one of her brothers." to justify doing exactly the same thing.
 * Nay's more nerdy habits in Khaos Komix are explained with this.
 * Silvia from Gold Coin Comics has two older brothers, and she tries to be like them by studying Time Magic.
 * Shelly of Wapsi Square had seven older brothers, and her mother died when she was around ten, so she was the only female around for much of her childhood. At present she is really tough, and worked as a mechanic for a while before she switched to being a personal trainer and kickboxing instructor.

Web Original

 * Gender Flipped in RWBY Volume 2, Episode 7 "Dance Dance Infiltration", when Jaune explains that it's because he has seven older sisters that he can dance as well as he does.

Western Animation

 * Foster's Home for Imaginary Friends: Mac and Frankie have called in to a radio show to win tickets to a new movie, but first they have to guess what romantic comedy the lead actor starred in. Mac immediately says, "Daffodil Days!" In response to Frankie's confused stare, he says his mom likes it.
 * Male verson: On Camp Lazlo, Raj plans 's wedding because "I have 17 older sisters. I think I know a thing or two about weddings".
 * Lor from The Weekenders has at least a dozen brothers (she's not sure exactly how many) and no sisters. She's enthusiastic about sports and very athletic.

Real Life

 * It has been said that Murasaki Shikibu (author of The Tale of Genji) learned how to write kanji (back then, men wrote in kanji while women were restricted to hiragana) by observing her brother's lessons.
 * Girls can and do sometimes pick up traits or tastes from their brothers that might otherwise be considered "unfeminine."
 * Studies of the behavioral effects of sex hormones have shown that female rats born to otherwise all-male litters tend to exhibit masculine behaviors, such as urine-marking and mounting to display dominance. Androgens from their numerous male siblings appear to have seeped over within the uterus, influencing the female pups' brain development.
 * Science aside, in America, all-girl households are horrified by basic things like farting and potty humor. That's because of the gender differences—if you're raising four kids, and three are boys, you end up punishing\rewarding the same behaviors in the same way, and the 'dominant' gender is masculine. Ergo, girls with fart jokes.