I Once picked my nose ‘til it bleeded. Child Language Acquisition in The Simpsons How do children learn to speak their native language? The answer to this question might seem obvious. They just copy their parents, right? Not so fast. Consider, for example, the following sentence spoken by Simpsons’ TV Anchorman Kent Brockman “And the elephant that couldn't stop laughing was put to death” (The Frying Game). Did Brockman learn this sentence as a whole from a parent, or, for that matter, from anyone else? Clearly not. Rather, he learned from his parents, and other native speakers, both the individual words and some kind of abstract rules or sentence patterns that allow these words to be put together to convey particular meanings. Explaining just how children do this is the goal of language acquisition research. There are essentially two possible answers. The first (e.g., Chomsky, 1957; Pinker, 1984) is that children are born with some empty categories (e.g., [NOUN] and [VERB]) and some basic rules for combining them into sentences (e.g., one possible sentence type consists solely of a [NOUN] and a [VERB]; e.g., (the) elephant laughed). On this view, children’s task is simply to fill in these pre-existing categories with words that they hear, and to find out which particular version of the sentence-construction rule applies in their language (e.g., is it [NOUN] then [VERB], like in English, or [VERB] then [NOUN] like in some other languages?). The second possible answer (e.g., Braine, 1963; Tomasello, 2003) is that children must build these generalizations from scratch on the basis of the language that they hear. For example, a child who heard The elephant laughed, The man shouted and The dog barked might abstract across these strings to build what is known as a slot-and-frame schema (e.g., The [PERSON/ANIMAL] [ACTION]ed); a pattern that allows entirely new sentences of the same form to be generated (e.g., The woman danced). The first approach is known as the nativist approach, because it stresses the importance of categories and rules that children are born with (a native of a country is someone who was born there; the nativity is the story of the birth of Jesus). The second approach is known as the constructivist approach because children instead construct these categories and rules from the language that they hear. In this chapter, we will compare and contrast the nativist and constructivist explanations for some of the major phenomena in language acquisition, on the basis of examples from The Simpsons. Lisa’s First Word: Word Learning. In the episode Lisa’s First Word, we discover the first word spoken by each of the Simpson children: “Aye Carumba” (Bart), “Bart” (Lisa) and “Daddy” Maggie (Daddy is actually the most common first word, slightly edging out Mummy; Fenson et al, 1994). But just how do children learn words? There are two basic problems. The first problem is finding where one word ends and the next begins (a problem that – in a roundabout way – is the source of Bart’s chalkboard gag “I will not scream for ice cream” in Lisa Gets an A). Unlike written text, speech doesnthavegapsinbetweenthewords. So how do children split up the stream into words? One nativist answer (e.g., Gambell & Yang, 2005) is that they are born with the knowledge that each word contains no more than one stressed syllable. So, for example, even the first time we heard his name, we knew that the bartender was called Moe/Syzslak and not MoeSyzs/Lak (Bold=stressed syllable, /=word boundary), because the latter would violate this rule by having two stressed syllables, Moe and Syzs, in the same word. One constructivist answer (e.g., Saffran, Aslin & Newport, 1996) is that children keep track of how often one syllable follows another, and assume a word boundary whenever a very rare combination turns up. So suppose Maggie hears herself described as a PRI-TY-BAY-BE (pretty baby). She can tell that the correct way to slice up this stream is PRI-TY/BAY-BE and not PRI/TY-BAY-BE, because the combination PRI+TY is quite common (and so probably a word) whilst the combination TY+BAY is extremely rare (and so almost certainly not). The debate between the rival accounts is ongoing. The first account works well in computer simulations, but is hard to test on real children. The second works well with children, but only with very artificial made-up languages. The second word-learning problem is figuring out what each word means. Say, for example, that Maggie hears someone Snowball as the cat walks past. How does she know that Snowball is the name of the cat? It could just as well mean “furry”, “tail”, “look at that”, and so on (Quine, 1960). One nativist answer (e.g,. Markman & Wachtel, 1988) is that children are born with assumption that new words label whole objects rather than properties (“furry”), parts (“tail”) and so on. The problem with this answer is that many words don’t label whole objects at all (e.g., party; the), so this assumption would actively hinder children much of the time. A constructivist answer (e.g., Tomasello, 2003) is that children understand what speakers are trying to do with their language, particularly when this language is part of familiar routines. For example, if Marge and Maggie often play a “naming game” together, Maggie will understand that when Marge says “Snowball” she is naming the cat rather than saying, for example “look at that”. A problem for this answer is that children seem to learn some words when they are just a few months only, and so probably unable to understand speakers’ intentions in this way. I Once picked my nose ‘til it bleeded: Morphology In Natural Born Kissers, Sideshow Mel, upon seeing Homer float past, exclaims “Look at that blimp…He is hanging from a balloon”. But if Mel were to recall the incident later, he would have to say “He was hanging from a balloon”. Similarly, in The Simpsons Spin-Off Showcase, “Lisa” sings a song called “I want candy”. But if she were singing about past candy-cravings, she would have had to sing “I wanted candy”; or, about someone else, “He wants candy”. The use of either whole words (e.g., is, was) or bits of words (e.g., - ed, -s) to indicate tense (e.g., past vs present) or the person that we’re talking about (I want vs He wants) is called morphology (and the words, or word-bits, morphemes). When learning systems of morphology, children typically make four characteristic mistakes. The task of theories of child language acquisition is to explain exactly why they do so. The first common mistake is to miss out these morphemes altogether. For example in the episode Trilogy of Error, when Lisa’s grammar robot, Linguo dies, Homer cries in alarm “Lingo…dead”. With its dying words, the robot corrects him, “Linguo is dead”. The most common nativist explanation (e.g., Wexler, 1998; Legate & Yang, 2007) is that children do this because they think that marking tense is optional. That is, they think you can include the “is” if you like, but, if you can’t be bothered, that’s fine. This isn’t as crazy as it might sound. First, there are lots of words that are optional, for example the “that” in Homer’s description of a dancer in Mayored to the Mob, “I think (that) I saw him in Rent or Stomp or Clomp, or some piece of crap”. Second, there are many languages in which speakers don’t mark tense at all. A speaker of Mandarin Chinese really would say (the equivalent of) “Lingo dead”, and it would be up to the listener to work out whether he meant is dead, was dead, will be dead etc. The problem for this account is that it can’t quite explain why these errors are much more common in some languages than others. The rival constructivist explanation (e.g., Freudenthal et al, 2007) is that children hear adults say things like “Is Linguo dead?”, store these sentences and re-use them, missing off the start of the sentence “Is Linguo dead”. This explanation works well for most languages, but doesn’t predict why English children make this error quite as much as they do (around 90% of the time for most 2- year-olds). The second common mistake that children make is using the wrong morpheme. This mistake is quite hard to see in children learning English, so I’m going to have to hope that, like Bumblebee Man (who is actually Belgian; see Simpsons Comic #110), you have learned just a little Spanish. Imagine that a Spanish child wants to say “They play” (talking about a group of people). The correct thing to say is “Ellos jeugan”, which has the plural (“they”) ending –an. But what Spanish-learning children often do (Aguado-Orea, 2004) is to use the singular (“he”) ending –a and say “Ellos jeuga”. As I said, this mistake is quite hard to spot in English, but the nearest equivalent would be something like the Italian mobster Louie’s “They’s throwing Robots” (Lingo: “They are throwing robots”). So why do sometimes children use the wrong morpheme? The nativist answer is basically to argue that they don’t (ignoring the very occasional slip of the tongue). This is because the nativist account assumes that children are born already understanding how systems of morphology work, and so should rarely trip up.