27) [(x – 5)*(x – 4)*(x – 3)*(x – 2)*(x – 1)] + x = y
With this rule, all inputs equal to or less than 5 will give an output equal to the input, but for all inputs greater than 5, they will give some large number.
When you hypothesized the rule was x = y, you didn’t have all the crucial information; you only had part of the data. This seems to mean that if you hear only the first five pieces of data in our table then you won’t get the rule, but if you learn the sixth you will figure it out. Is this necessarily the case? Unfortunately not: Even if you add a sixth line, you have no way of being sure that you have the right function until you have heard all the possible inputs. The important information might be in the sixth line, but it might also be in the 7,902,821,123,765th sentence that you hear. You have no way of knowing for sure if you have heard all the relevant data until you have heard them all. In an infinite system, you can’t hear all the data, even if you were to hear 1 new sentence every 10 seconds for your entire life. If we assume the average person lives to be about 75 years old, if they heard one new sentence every 10 seconds, ignoring leap years and assuming they never sleep, they’d have only heard about 39,420,000 sentences over their lifetime. This is a much smaller number than infinity. Despite this poverty of input, by the age of 5 most children are fairly confident with their use of complicated syntax. Productive systems are (possibly) unlearnable, because you never have enough input to be sure you have all the relevant facts. This is called the logical problem of language acquisition.
Generative grammar gets around this logical puzzle by claiming that the child acquiring English, Irish, or Yoruba has some help: a flexible blueprint to use in constructing her knowledge of language called Universal Grammar. Universal Grammar restricts the number of possible functions that map between situations and utterances, thus making language learnable.
You now have enough information to try CPS8 & 9.
6.4 Other Arguments for UG
The evidence for UG doesn’t rely on the logical problem alone, however. There are many other arguments that support the hypothesis that at least a certain amount of language is built in.
An argument that is directly related to the logical problem of language acquisition discussed above has to do with the fact that we know things about the grammar of our language that we couldn’t possibly have learned. Start with the data in (28). A child might plausibly have heard sentences of these types (the underline represents the place where the question word who might start out – that is, as either the object or the subject of the verb will question):
28)
| a) Who do you think that Siobhan | will question _____ first? |
| b) Who do you think Siobhan | will question _____ first? |
| c) Who do you think _____ | will question Seamus first? |
The child has to draw a hypothesis about the distribution of the word that in English sentences. One conclusion consistent with these observed data is that the word that in English is optional. You can either have it or not. Unfortunately this conclusion is not accurate. Consider the fourth sentence in the paradigm in (28). This sentence is the same as (28c) but with a that:
d) *Who do you think that _____ will question Seamus first?
It appears as if that is only optional when the question word (who in this case) starts in object position (as in 28a and b). It is obligatorily absent when the question word starts in subject position (as in 28c and d) (don’t worry about the details of this generalization). What is important to note is that no one has ever taught you that (28d) is ungrammatical. Nor could you have come to that conclusion on the basis of the data you’ve heard. The logical hypothesis on the basis of the data in (28a–c) predicts sentence (28d) to be grammatical. There is nothing in the input a child hears that would lead them to the conclusion that (28d) is ungrammatical, yet every English-speaking child knows it is. One solution to this conundrum is that we are born with the knowledge that sentences like (28d) are ungrammatical.11 This kind of argument is often called the poverty of the stimulus argument for UG.
Most parents raising a toddler will swear up and down that they are teaching their child to speak and that they actively engage in instructing their child in the proper form of the language. The claim that overt instruction by parents plays any role in language development is easily falsified. The evidence from the experimental language acquisition literature is very clear: parents, despite their best intentions, do not, for the most part, correct ungrammatical utterances by their children. More generally, they correct the content rather than the form of their child’s utterances (see for example the extensive discussion in Holzman 1997).
29) (from Marcus et al. 1992)
1 Adult: Where is that big piece of paper I gave you yesterday?
2 Child: Remember? I writed on it.
3 Adult: Oh that’s right, don’t you have any paper down here, buddy?
When a parent does try to correct a child’s sentence structure, it is more often than not ignored by the child:
30) (from Pinker 1995: 281 – attributed to Martin Braine)
1 Child: Want other one spoon, Daddy.
2 Adult: You mean, you want the other spoon.
3 Child: Yes, I want other one spoon, please, Daddy.
4 Adult: Can you say “the other spoon”?
5 Child: Other … one … spoon.
6 Adult: Say “other”.
7 Child: Other.
8 Adult: “Spoon”.
9 Child: Spoon.
10 Adult: “Other … spoon”.
11 Child: Other … spoon. Now give me other one spoon?
This humorous example is typical of parental attempts to “instruct” their children in language. When these attempts do occur, they fail. However, children still acquire language in the face of a complete lack of instruction. Perhaps one of the most convincing explanations for this is UG. In the problem set part of this chapter, you are asked to consider other possible explanations and evaluate which are the most convincing.
There are also typological arguments for the existence of an innate language faculty. All the languages of the world share certain properties (for example they all have subjects and predicates – other examples will be seen throughout the rest of this book). These properties are called universals of Language. If we assume UG, then the explanation for these language universals is straightforward – they exist because all speakers of human languages share the same basic innate materials for building their language’s grammar. In addition to sharing many similar characteristics, recent research into Language acquisition has begun to show that there is a certain amount of consistency cross- linguistically in the way children acquire Language. For example, children seem to go through the same stages and make the same kinds of mistakes when acquiring their language,
