I've had a few requests to post this as a sticky.

A little background: When I interned at a literary agency a few years ago, I wrote this outline as part of my final project. Keep in mind the results of this project are not "an agent's view" of the differences between YA and MG, but a compilation of my research.


MIDDLE GRADE, YOUNG ADULT AND ADULT FICTION

Relatively speaking, young adult fiction is a new marketing category. In the 19th century, publishers did not market to younger audiences. Some novels, however, still appealed to young readers:
  • SWISS FAMILY ROBINSON, OLIVER TWIST, GREAT EXPECTATIONS, ALICE IN WONDERLAND, TREASURE ISLAND, HUCKLEBERRY FINN, THE JUNGLE BOOK

Novels like THE YEARLING and THE SECRET GARDEN also predate the young adult category, but are now considered YA. CATCHER IN THE RYE and LORD OF THE FLIES also predate the category and were written for adults, but nonetheless captured a large teen audience.

GENERAL GUIDELINES: The book should mirror the readers’ personal experiences. The age of the character is similar to that of the reader, but the age should fit the character. (Younger readers tend to read up.) The story is about the character, not the theme.

Readers do not make a book adult or young adult; publishers do. Because publishers have invented the marketing category, some books cross age levels. Publishers have taken the category and expanded it to market even smaller age groups: 6-8, 9-12, 10-14, and 15+.

MIDDLE GRADE
  • Under 12
  • 100 pages or shorter
  • At this point, readers should be comfortable with any vocabulary or sentence structure.
  • The readers are focused on personal, internal conflict, and so are the characters.
  • Readers want to know how they fit within their own world, like discovering or confirming their identity, or taking on new responsibility.
  • Characters change on the inside.
  • Less emphasis on swearing, sex or adult behavior.
  • Ex: A SERIES OF UNFORTUNATE EVENTS by Lemony Snicket, THE WAINSCOTT WEASEL by Tor Siedler, ALEX AND THE IRONIC GENTLEMAN by Adrienne Kress, HARRY POTTER AND THE SORCERER'S STONE by J.K. Rowling

YOUNG ADULT
  • Over 12
  • Generally 40,000-70,000 words
  • Profanity is determined by the age group and the publisher’s preference, but more importantly, whether it’s necessary and fitting for the character to use them.
  • Characters are still key, but the conflict may be more complicated.
  • The protagonist still experiences internal change, but that change is usually triggered by the external events – they want to know how they influence the world.
  • Usually, the characters are moving beyond what is comfortable and normal, and encountering new, and more adult, territory.
  • Themes of racial hatred, prejudice, violence may be present. The story lets readers explore unfamiliar conflicts.
  • Sex, love and lust are strong motivators for behavior. Sex is not described explicitly, but it is obvious. Some novels, like SISTERHOOD OF THE TRAVELING PANTS by Ann Brashares, allude to sex so that older readers understand the reference but not younger ones.
  • Common themes also include: the difference a person can make, importance of relationships, coping with tragedy. Scarier subjects are also addressed with the characters’ friends as the ones in the most dangerous situations.
  • The conflict may appear melodramatic, but teenagers are melodramatic – “they want to know why they feel like shit.”
  • Ex: GOSSIP GIRL by Cecily Von Ziegesar, TWILIGHT by Stephenie Meyer, THE PERKS OF BEING A WALLFLOWER by Stephen Chbosky, WICKED LOVELY by Melissa Marr, HARRY POTTER AND THE DEATHLY HALLOWS by J.K. Rowling

EDGY YA
  • Generally aimed at older teens.
  • Formerly taboo subjects are handled with care and sensitivity.
  • Abuse, cutting, suicide, rape (male and female), drugs, incest, peer pressure, crime and disease are all motivators for conflict. However, introspective is usually strong, and if the readers cannot identify with the actual situation, they should be able to identify with the emotion.
  • Ex: GO ASK ALICE by Anonymous, SPEAK by Laurie Halse Anderson, RAINBOW BOYS by Alex Sanchez, CUT by Patricia McCormick, SMACK by Melvin Burgess .

ADULT FICTION
  • In terms of theme and conflict, anything goes.
  • Adult fiction puts teenage years in perspective of the character’s entire life: Adults have been teenagers, but teenagers have never been adults. Young adults may be reaching to adult fiction to gain a different perspective.
  • “Most teenage fiction has an invisible ring of safety built into it. However sticky situations get, however dark the material, little signals here and there give off the message that this is 'only' a kids' book. Don't worry. Nothing too bad will happen.” – Mark Haddon
  • That sense of safety is nonexistent in adult fiction (depending on the genre), which may be why many YA readers turn to adult fiction.
  • THE CURIOUS INCIDENT OF THE DOG IN THE NIGHT-TIME (an ALEX award-winner) and LIFE OF PI by Yann Patel are two books that received teenagers’ attention. Others include PRIDE AND PREJUDICE by Jane Austen and THE LOVELY BONES by Alice Sebold.

In addition to the themes and ideas I address above, one of the biggest factors (if not the biggest) in determining where your novel stands is VOICE.

For example, I mention above Yann Patel's novel LIFE OF PI as an example that appealed to both young adult and adult readers. The protagonist of the novel is a teenager, but the narrator is the teen as an adult. This style addresses the second bullet point under "Adult Fiction"--
adult fiction puts teenage years in perspective of the character’s entire life. The voice is that of an adult, with perspective and distance from the events as they happened to him as a teen.

So, among everything else addressed here, make sure to take your voice into account.