Question

2. What is the difference between positive and negative evidence? How does the fact that children do not rely on negative evidence support the claim that there is an innate Universal Grammar? How does the fact that children (almost) only rely on positive evidence support the claim that there is an innate Universal Grammar? Use an example to illustrate each of these parts of the Poverty of Stimulus argument.

Answer 1

Positive evidence is the set of grammatical sentences that the language learner has access to, as a result of observing the speech of others. Negative evidence, on the other hand , is the wvidevid available to the language learner about what is not grammatical. Positive evidence means that you have evidence directly indicating the conclusion. Negative evidence means that you are lacking evidence to establish the opposite conclusion, so therefore you make the conclusion based on the lack of evidence.

An example of negative evidence is the claim that there is an elephant in my house. I can exhaust the search all over my house , and find no elephant, no footprint, no sounds of the elephant, and no collateral damage that would have to occur from an elephant stampeding all over in my house. I therefore conclude that this claim is false.

Now suppose I replaced that elephant, with a house cat. I know I don't own a cat, but you claim that there is one in my house. I can do a general search for evidence of this cat throughout my house and be unsuccessful. But remember, a house cat can be very good at hiding. And leave no evidence of one's self. Sneaking behind me, and hiding in a place I have already checked. Therefore, by not finding any clues as evidence of the cat, that isn't sufficient evidence of the absence ot the cat.