This might explain why making Clary jealous doesn’t actually work in the long run. Jace is the one Clary is instantly attracted to and ultimately the one she wants—the aloof enigmatic boy who kisses her in the hallway outside her bedroom. Even when Simon interrupts the kiss and admits his feelings for Clary, professing “I’ve been in love with you for ten years,” he still doesn’t get the girl. Like Andie, Clary feels guilty and torn. But in the end, she can’t fight the way she feels, and Jace wins out.

Case Study 2: Sixteen Candles (John Hughes, 1984)

Sixteen Candles is another example of the Duckie effect at work. In the film, Samantha is turning sixteen the same weekend her older sister is getting married. Relatives descend on the house, along with a foreign exchange student, and Sam loses her room and her family’s attention. School is a welcome distraction, especially since her secret crush, Jake Ryan, is there.

Sam’s “Duckie” is more of an accidental friend than a lifelong best friend. Farmer Ted, as Sam calls him, is king of the geeks, and he bets his friends that he can “make it” with Sam at the school dance. The same night, Sam’s family forgets her sixteenth birthday. She shares a moment with Jake before his nightmare diva of a girlfriend drags him off to a party. Sam retreats to the school auto shop, where she spills her guts to best friend stand-in Farmer Ted and he tries to kiss her. Farmer Ted never gets a kiss (though Sam does give him her underwear so he can save face with his friends), and she ends up with Jake.

Farmer Ted and Simon have less in common than Duckie and Simon, since Farmer Ted isn’t technically Sam’s best friend. He does give Sam a shoulder to cry on and throws her an emotional life preserver when she needs one. But anyone who has ever harbored a monster crush knows a shoulder to cry on is no match for hundreds of class periods spent combining your name and your crush’s (especially if you added his last name to your first name just to “see how it would look”). This is particularly true of young women in literature and film, who suffer extreme cases of the grass always being greener on the other side. They seem to be more interested in the unattainable than in the boy who’s busy adding his last name to theirs.

Exhibit B : Simon is the grass on this side—the known quantity.

Simon is the boy Clary confesses her hopes and fears to in the auto shop, not the boy whose name she writes over and over in class—or, in the case of Shadowhunters, the boy upon whose skin she draws runes.

Clary isn’t the only one who needs an emotional life preserver. In City of Bones, Simon admits (though Clary denies it), “I’ve always been the one who needed you more than you needed me.”

This brings up another important distinction between Duckies and guys who get the girls: The guy who gets the girl avoids showing both physical and emotional vulnerability, except to the one girl he cares about.

Exhibit C: Jace bleeds and battles demons and still has enough energy to make a smartass comment afterward, while Simon just bleeds.

Unlike Simon, Jace doesn’t seem to lean on anyone. He suffers silently, hiding the pain of losing his parents, his insecurities, even his feelings for Clary at first. As the series continues, we learn Jace’s secrets along with Clary, and discover that he is more vulnerable than we could’ve imagined, which only makes him even more wounded and irresistible. To their detriment, Duckies are never wounded and irresistible (physically wounded maybe, but that’s not quite as sexy).

Case Study 3: St. Elmo’s Fire (Joel Schumacher and Carl Kurlander, 1985)

Another common denominator best friends in film and literature share is pining. You know, silently brooding over the girl you’re madly in love with year after year without saying a word.

The ultimate case study in best friend pining is Kevin, Andrew McCarthy’s character in the movie St. Elmo’s Fire. In the film, seven best friends graduate from college, and their lives slowly fall apart, tearing their friendship apart along with them. Almost everyone in St. Elmo’s Fire seems to have hooked up at some point, but Leslie and Alec are an actual couple. The turning point in the movie occurs when the lives of all seven of the characters are spinning out of control, and Leslie confronts Alec about his “extracurricular love life.” Alec throws Leslie out of their apartment, and she ends up at her best friend Kevin’s place.

They both drink too much, Leslie finds a box full of pictures Kevin has secretly snapped of her over the years (can anyone say stalker?), and Kevin admits that he’s been in love with her since they met. But viewers know Kevin is in love with Leslie long before she figures it out. The way he seems uncomfortable when Leslie and Alec are together, the awkward glances and longing looks—it’s all right there on the screen.

In the case of Simon, it’s right there on the page as soon as the Mortal Instruments series begins.

Exhibit D: Simon has been in love with Clary for years.

The boy who gets the girl never pines. He kisses her in the hall and takes her breath away, or he kisses her in front of the Seelie Court, even when he thinks she’s his sister (a fact made less creepy by the fact that we know it doesn’t turn out to be true). In City of Ashes, everyone watched when “Jace [took] Clary in his arms with such force Simon… thought one or both of them might shatter” and “held her as if he wanted to crush her into himself.”

Another similarity between Kevin’s relationship with Leslie and Simon’s relationship with Clary is that when both guys seem to “get the girl,” the spark is short-lived. The only thing that’s more obvious than Kevin’s pining in the first half of St. Elmo’s Fire is Leslie’s lack of passion for him when they are finally together in the second half. Like Simon in the beginning of City of Ashes, Kevin has the only thing he’s ever wanted—the girl he’s secretly loved for so long. But it’s a crushing revelation (Alec’s infidelity) that brings Kevin and Leslie together, not genuine interest on Leslie’s part, just as Simon gets a chance with Clary only after she learns that Jace is her brother.

In both cases, the girls are emotionally devastated by the realization they can’t be with the guys they truly love. So whom do they turn to? The guys who love them so much they are willing to be the rebound guys. It’s easy to fall back on someone you know is waiting in the wings, especially if your heart and self-esteem are in pieces at your feet. Who better to glue you back together than your best friend? Unfortunately, gluing you back together isn’t usually enough to turn friendship into attraction.

Exhibit E: The proof is always in the pudding, or in this case the kiss.

In City of Ashes, Clary describes kissing Simon as “a gentle sort of pleasant, like lying in a hammock on a summer day with a book and a glass of lemonade,” while kissing Jace is the opposite of pleasant, “like opening up a vein of something unknown inside her body, something hotter and sweeter and bitterer than blood.” Hmm…let’s see, “a book and a glass of lemonade” or “hotter and sweeter and bitterer than blood”? Which one would you choose?

It’s worth noting that Leslie doesn’t really choose at the end of St. Elmo’s Fire, claiming she needs some time without Alec or Kevin to decide what’s right for her, but who are the screenwriters kidding? We all know Leslie was just throwing her best friend, Kevin, a bone. In a month, you can bet she was making out with Alec again, and they probably didn’t need a Seelie Queen to make it happen.

Case Study 4: The Outsiders (Kathleen Rowell, Based on the Novel by S. E. Hinton, 1983)

The film The Outsiders, based on the book by the same name, is a case study in another aspect of the Duckie effect. No matter how gorgeous and heroic the best friend is, the other guy is more gorgeous, more heroic, more mysterious—more everything.

In The Outsiders, Ponyboy, a working-class Greaser, becomes friends with Cherry, a gorgeous Soc (short for socialites, the rich kids in the novel) from the other side of the tracks, when he chases off some other Greasers harassing her at the movies. Cherry and Ponyboy end up becoming friends, and he likes her. Granted, he hasn’t been pining for Cherry for years, but a crush on a Soc girl is no joke; it’s something we eventually learn can get you killed.

Dallas Winston is also a Greaser, and a friend of Ponyboy’s. But he doesn’t spend his time reading poetry and contemplating the social divide between the Greasers and the Socs like Ponyboy does. Dallas is too busy drinking and fighting and running from the cops, when he isn’t robbing liquor stores and hitting on girls. Cherry meets Dallas only once, and he’s less than charming, but her takeaway from the experience says it all: “I hope I never see Dallas Winston again. If I do I’d…probably fall in love with him.” Dallas embodies the bad boy, something the best friend will never be.

Exhibit F : Jace embodies the bad boy, and Clary is immediately attracted to him because of it.

In City of Ashes, Simon remembers the first time he noticed the way Clary reacted to “the blond boy with the strange tattoos and the angular, pretty face [Jace] as though he were one of her animated heroes come to life. [Simon] had never seen her look at anyone that way before”—including him. Jace is Clary’s Dallas Winston, a gorgeous, rule-breaking bad boy, who seems more like a superhero with his tough exterior and I-don’t-need-anyone attitude. From the moment she meets Jace, she can’t forget him, and despite his sarcastic comments, she can’t fight her attraction to him any more than Cherry can fight her attraction to Dallas. Like Simon, Ponyboy doesn’t get the girl either.

Lots of readers will argue that Simon does get the girl, it’s just not Clary, and that’s true. But that doesn’t challenge the basic principle of the Duckie effect, which is the best friend never gets the girl.

The Exception

It’s interesting to note that the opposite outcome is true when the person in love with her best friend is a girl instead of a boy. In literature and film, the girl always seems to get the guy, even if the girl is shy, geeky, or dare I say average looking. We only need to look to one ’80s film to see how this scenario plays out because it’s always the same; the girl is in love with her best friend, who chases some unattainable girl until he finally gets her and realizes it was his best friend he was in love with all along.

In John Hughes’ 1987 film Some Kind of Wonderful, Keith’s best friend, Watts (a girl), is secretly in love with him. Keith has no idea, in part because he is completely fixated on Amanda Jones, a girl who is way out of his league. Watts buries her feelings and agrees to help him with an elaborate plan to win Amanda’s heart, which tears Watts’ heart to shreds in the process. Unbelievably, as it always seems to happen when a girl is in love with her male best friend, the boy (Keith, in this case) manages to get the fantasy girl. The difference? At the last minute, Keith suddenly realizes he’s really in love with Watts and chases her down the street to give her the diamond earrings he planned to give to Amanda.

So what gives? Why do the girls end up with their best friends? Why aren’t they Duckies too? The message seems to be that guys don’t always know what they want—or who is right for them—until a resourceful young woman finds a way to show them. While this portrait of literary and cinematic boys in general is less than flattering, is it any less flattering than the portrait of girls who undergo some sort of chemical reaction the minute they meet an emotionally unavailable bad boy? Unless the bad boy in question isn’t really bad at all (like Jace). What if these fictional girls empower a few of us who are more Watts than Amanda Jones to go after our own Jace Waylands anyway, off the screen and the page? Girls going after what they want in literature, and life, always get my vote.

Couldn’t ending up with a Duckie be just as empowering? Unfortunately, most film and literature heroines will never find out, though more than a few real girls know the truth: Sometimes your best friend also happens to be the best choice.

Until then, like crop circles, UFOs, the Bermuda Triangle, and ESP, the Duckie effect is an unexplained phenomenon. Only one thing is certain: Even if he’s an adorable Jewish vampire, the best friend never gets the girl.

Kami Garcia is the New York Times, USA Today, Publishers Weekly, and international bestselling coauthor of the Beautiful Creatures novels. Beautiful Creatures releases in theaters in 2013 from Warner Brothers and Alcon Entertainment, starring Viola Davis, Jeremy Irons, Emma Thompson, Alice Englert, Alden Ehrenrich, and Emmy Rossum. Kami is also the author of Unbreakable, the first book in her solo series, The Legion (Little, Brown, 2013), which is currently being developed as a major motion picture. You can find out more about Kami and her books at www.kamigarcia.com or follow her on Twitter at @kamigarcia.

Kendare Blake

I’ve caused a lot of consternation among fans with the Jace/ Clary sibling plotline. I know this because of the amount of AUGH and ICK that have come my way over time. But isn’t that what we want from a story? For it to make our hair stand on end? For it to make us question our assumptions about what sort of love is acceptable to us, and why?

You can probably tell that I’ve written about this too much already, as evidenced in my language having devolved to “AUGH” and “ICK,” which is why I’m so glad Kendare has swooped in with this articulate essay, rescuing me from any further embarrassment.

Brotherly Love

Jace, Clary, and the Function of Taboo

There’s a reason that stories end at Happily Ever After. Happy couples are boring. Bo-ring. It’s all kissy faces and “honey-bear this” and “snuggle-pie that.” It’s sweet, and deep, and meaningful. And it makes us want to close the book. As readers, we’re drawn in by the struggle, by the drama, by the desires of the characters. There are few things in literature more enthralling to read than the tale of two people who yearn to be together. The great love stories tell us that to be truly engaging, couples should yearn against seemingly insurmountable obstacles. The more a couple has to overcome, the more forbidden the romance, the more we root for them. The young lovers of Romeo and Juliet defied a family feud and married in secret. Jack Twist and Ennis Del Mar fought against societal constraints and shame in Brokeback Mountain. Lancelot and Guinevere overcame the constraints of common sense and decency. In Cassandra Clare’s Mortal Instruments series, Jace Wayland and Clary Fray overcome the taboo of sibling incest, and they do it without ever crossing the grossout line.