Blank Slate

""What's interesting to me.. .is that you don't call out to God. It isn't a question of faith, it's just vernacular. Anyone in this much pain prays, or at least curses, but... we take God from you too. You really are a shell.""

- Bennett, Dollhouse

A Blank Slate is an empty character with no beliefs, no opinions, and no experience, ready to be shaped by the outside world. Sometimes this is an extreme case of Fish Out of Water, in which a character is transported into a world that they literally know nothing about. Other times, this is the result of a character being created by magic, or mad science, and thus the character is essentially "born" with the mind of an adult, but no life experiences whatsoever. In some instances, this is actually the result of a mind wipe.

Whatever the case, the result is the same: a non-prejudiced character whose views are ready to be shaped by the outside world, whoever the character meets first, or the character's creator.

Compare the Seemingly-Profound Fool, who is similarly uninformed and thrust into a "new" world, but who changes others in a reversal of this trope. Laser-Guided Amnesia might turn you into this. Criminal Amnesiac is what happens if such a person is taken advantage of by the bad guys. Contrast with the Empty Shell, who usually goes the other way and ends up like this.

See also OC Stand-In, the Fanfic counterpart of this trope where non- or under-developed characters are given more quirks and personalities.

Anime and Manga

 * In Elfen Lied, throughout the anime and the first half or so of the manga, Nyu (Lucy's innocent, harmless personality) is a Blank Slate—she has no useful speech abilities, latches emotionally on to the first people she meets, and frequently doesn't seem to understand what's going on.
 * In Chobits, Chi is a Blank Slate when she is first turned on, having to learn everything anew including language, how to buy things from a shop, and how to take a bath. She also latches emotionally onto the first person she meets, the protagonist Hideki.
 * One of the theories about Eureka from Eureka Seven is that Eureka was deliberately sent to humans as a blank slate, with the intention of seeing what she turned into under the influence of humanity.
 * Ennis in Baccano! starts as one of these and gradually develops more of a personality..
 * There's a lot of hints in Chrono Crusade that Fiore started out this way before she became the subservient Meido for Aion and Joshua. She often still insists she's one, but she has quite a bit more personality and will than she lets on. In the manga, she possibly would've stayed this way if

Film

 * The historical figures in Bill and Teds Excellent Adventure are blank slates, as they have never encountered modern culture. Their individual personalities quickly assert themselves, where each past-dude finds a new interesting thing in the present.
 * The Ali Landry film Repli-Kate revolves around this trope; the hero is in love with the beautiful Kate but far too nervous to talk to her. When she is accidentally cloned the hero and his roomate educate the Blank Slate clone with sterotypical guy traits like love of sports and casual sex. Hilarity Ensues.
 * I believe they said on the commentary track to Big Fish that the Billy Crudup character's wife was supposed to be a blank slate with no biases. That was her virtue.
 * A 1970 movie, The Mind of Mr. Soames, starred Terence Stamp as a man who'd been born in a coma—and maintained in a coma until his (remarkably physically fit) thirtieth year.
 * The 1920 silent movie The Golem hinges on the premise that the eponymous character is completely clueless about how the world works.

Literature

 * Frankenstein... The book version, anyway. The Creature is essentially "born" without any idea of what the outside world is like, especially since Victor (his creator) ran out on him, because of his apparently hideous appearance... in fact, it's because of the disgusted reactions of others towards how he looks (the very negative reaction) that he starts to turn toward doing evil; no one will ever try to get to know the real him...
 * The Generics, two newly-minted characters, are initially called ibb and obb, and evolve into Lola and Randolph as they develop personalities before they try for roles in books in the Thursday Next book The Well of Lost Plots.
 * The Israeli novel Pere (=Wild) deals with a person being born in an adult body, without knowing why.
 * The classic science fiction novel Adam Link, Robot is essentially an answer to the question, "What if Victor Frankenstein had been a responsible father to his monster?" Adam is a metal robot, and his builder does his best to raise him wisely and with kindness. Unfortunately, the builder dies, and Adam is falsely accused of killing him; but by then, thanks to his dad, Adam has already developed a personality as an intelligent, honest, and honorable guy—he just has to prove it to the rest of the world.
 * This partially applies and partially doesn't in The Worthing Saga. Suspended Animation has a side effect of completely erasing the memories of those who undergo it, which usually isn't a problem since the memories can be recorded beforehand and reinserted. When the main character is piloting a colony ship to another planet, a ship from a hostile faction attacks his ship and destroys the section in which the recordings were kept, so he winds up taking care of "adult infants" on the planet they come to. Some of them develop different personalities (generally for the better) as they acquire new memories and new experiences. However, parts of who they were are retained, and it's furthermore stated that giving them the memories of other people would probably have caused insanity.
 * In The Candy Shop War,

Live Action TV

 * Star Trek: The Next Generation: The character of Data was largely agreed to begin the series as a blank slate, so much so that Brent Spiner was often warned that he might seem like a "boring" character to play. But Data was a living, growing machine, who would change and develop via his experiences with humans and other assorted species. Spiner pulled this off pretty damn well.
 * The later android B4 (a more basic verison of Data) was also a blank slate, though possibly without Data's ability to grow and adapt.
 * Another TNG episode also had a type of Metamorph character (usually male, but there was a female born every now and then) who adapted themselves perfectly to whichever member of the opposite sex (and species) they were with, and resultingly aqccuried that person's tastes, dislikes and traits. They eventually settle on one individual and bond to them as their mate. One female (being delivered as a peace offering from one warring planet to another), was accidentally let loose on the Enterprise and spent her entire time there adapting to every male she came across, from a roughian group of traders, to the Captain, to a Klingon. They stuck her with Data since he didn't have a subconscious to read into and she therefore couldn't "bond" with him. Unfortunately she ended up bonded to Picard when she was supposed to save her bonding for the person she was being gifted to, and had to spend the rest of her life faking her required personality.
 * There was also Hugh Borg, who had no idea how to act without the Collective's instructions. TNG got a lot of mileage out of this trope.
 * Kyle [as in XY] started out as this.
 * Luke in The Sarah Jane Adventures before Sarah-Jane adopts him.
 * The 'tabula rasa' in Dollhouse.
 * And the episode of the same name in Buffy. Remember Joan?
 * The Journey of Allen Strange had created a Blank Slate by making a mannequin come to life, to play the role of Allen's father. (Allen is a space alien disguised as a human, and needed to fake having a human father.) The mannequin acted very odd, saying random things, and needed to have his behavior molded to be more appropriate.

Real Life

 * Babies.
 * As to what extent this is true... See Nature versus nurture
 * Truth in Television -ish: the chatbot Jabberwacky is unique among its kind in that it has no stock phrases; instead, all of its responses are things people have said to it in the past, selected according to relevance. This avoids some of the Robo Speak tendencies of older chatbots, and allows Jabberwacky to come out with unexpected, interesting and even occasionally profound statements. It won't be passing the Turing Test anytime soon, and its conversation can often be random and self-contradictory, but at least the things it says sound like something a human would say (because they were).
 * This troper would like to thank the above troper, but would also like to argue the turing test value of it. I lost an argument to it across two languages. It's learned quite well from a blank state beginning
 * Not unique at all, actually. Mega HAL, as well as most learning chatbots, start as a "blank slate" with no responses.
 * This is how all humans start out according to the Empirism theory of knowledge.

Tabletop Games

 * Prometheans in Promethean: The Created refer to the process of coming to life as "waking up on the slab" - waking up in an adult body with no knowledge of anything, except for basic physical coordination and one language spoken by the person (or people) whose corpse the Promethean now occupies. The odds of their creators being there to teach them anything are pretty low, as well, so they have to learn fast.

Video Games

 * Saya no Uta has start this way, minus her instinct to . Everything else, including her gender, reasoning, morality and emotions were obtained from contacts with humans. Seeing all things she does during the course of the story doesn't paint a good image of humanity. She was shown to be naturally super-intelligent though.
 * Nobodies have shades of this, but Roxas and Xion play it straight.

Web Comics

 * The Inexplicable Adventures of Bob has four artificial beings who all start out this way: Molly, Golly, Jolly, and Roofus. At least the girls had the advantage of being born staggeringly intelligent, allowing them to learn quickly. Roofus is a little denser, but seems all the more soulful for that.

Web Original

 * Anyone who has been nixed in Wormtooth Nation becomes one of these.

Western Animation

 * Transformers: Beast Wars: Quickstrike and Silverbolt's stasis pods were damaged by the surge at the end of season 1/start of season 2, which led to them awakening with no idea of who they are. Megatron uses this to his advantages by convincing them that they are Predacons. It works out with Quickstrike, but not so much with Silverbolt because he at least retained his honorable personality.
 * Quickstrike had a personality too. Ax Crazy. His just worked well with the Predacons, and Silverbolt's personality, not to put too fine a point on it, didn't. Tigatron would be a better example, since he "hatched" with no identity or allegiance and ended up becoming a tiger, which apparently means a lone-wolf nature-loving pacifist.
 * Wreck-Gar in Transformers Animated is malleable to the point of changing alliances based on the last suggestion he hears. Repeatedly.
 * Amazo in the Justice League animated series
 * Quite ironic too, as his ability was to absorb all information that he targeted, which was the justice league itself. Within a few years, he essentially became a god of the DC Universe. Quite good considering he literally started as a Blank Slate, unlike say, Superman....
 * This happens to Kim Possible when she has her memory erased. She becomes incredibly passive and docile while waiting to be told who she is, combined with a stepford smile for most of the time.