Arguments for Nativism
Various other facts about child language add
support to the Nativist argument:
•Accuracy (few ‘errors’)
•Efficiency (quick, easy)
•Uniformity (within and across languages)
•Constrained (POS)
Poverty of the Stimulus
If
(i) children know X, and
(ii) evidence for X is not sufficiently present
in the input to children,
then X must be innate.
 Children come to know things that they
should not know, given what they hear.
Example of the POS:
auxiliary inversion (Chomsky, 1971)
(1)
the girl is in the market
Example of the POS:
auxiliary inversion (Chomsky, 1971)
(1)
the girl is in the market
Example of the POS:
auxiliary inversion (Chomsky, 1971)
(1)
Is the girl [t] in the market ?
Principle of Y/N Question
Formation:
 Move the auxiliary to the front of the sentence.
This works for 99% of the sentences in English.
But not all…
Sentences with Multiple Auxiliaries
John is in the house now that it is raining.
Sentences with Multiple Auxiliaries
John is in the house now that it is raining.
Is John [t] in the house now that it is raining?
Sentences with Multiple Auxiliaries
John is in the house now that it is raining.
Is John [t] in the house now that it is raining?
*Is John is in the house now that it [t] raining?
Revised Principle of Y/N Question
Formation:
 Move the first auxiliary to the front of the
sentence.
The girls is in the market
John is in the house now that it is raining.
But…
a.
The child that is sitting on the floor is
hungry.
b.
*Is the child that [t] sitting on the floor is
hungry?
c.
Is the child that is sitting on the floor [t]
hungry?
So what’s the principle?
[The child that is sitting on the floor] is
hungry.
So what’s the principle?
Is [the child that is sitting on the floor] [t]
hungry?
So what’s the principle?
• Linear Order Hypothesis (Incorrect):
To make a yes-no question, front the first
auxiliary.
• Structural Dependency Hypothesis (Correct):
In order to make a yes-no question, front
the main auxiliary.
How does a child learn this?
•The child must hear sentences of the
following kind:
Is the child that is sitting on the floor hungry?
•Nativists argue such evidence is stunningly rare in CDS.
•Crain & Nakayama (1987) show children aged 3;2 have
knowledge of this principle.
Poverty of the Stimulus
At its heart, the POS argument is a problem
of INDUCTION.
Induction: how do you go from individual
examples to a generalized rule?
Induction
A simple example:
1
2
…
What’s the next number in this progression?
3?
4?
7?
The Induction Problem
• You’re about to see 5
slides of 3 colored
bars in frames.
• The first 4 slides
exhibit a property that
you need to learn.
• Decide whether or not
the 5th slide exhibits
the property in
question.
1
2
3
4
?
Answer
 NO
 The property in question in whether the
area covered by the bars is greater than
50% of the area of the rectangle.
• This generalization is more natural for
pigeons to learn than for humans.
Try it again
1
2
3
4
?
Answer
• YES
• Property in question in whether the 3 bars
are unequal in height.
• This generalization is more natural for
humans than for pigeons.
Try it again
1
2
3
4
?
Answer
 YES
 You only saw examples decreasing in
height from left to right. But the
generalization was still that the bars
only had to be different heights.
Try it again
1
2
3
4
?
Answer
• YES
• Property in question is whether the 3 bars
are unequal in height.
• But what about the 4th example?
• Oh, that? It was a mistake.
The Induction Problem
• You have to be able to discern the
relevant dimension(s)
• Any set of input data potentially allows
an infinite number of generalizations.
• How does an unbiased learner select the
one correct hypothesis from amongst
these infinite hypotheses?
Returning to Yes-No Question
Formation
• Linear Order Hypothesis (Incorrect):
To make a yes-no question, front the first
auxiliary.
• Structural Dependency Hypothesis (Correct):
In order to make a yes-no question, front
the main auxiliary.
So how do kids learn the correct
principle?
Children are born with the
knowledge that language is
dependent on structure, not
linear order.
Lawn Bowling
This is the current state of the field
A ball is about to be bowled
This is the final state of the field
How did you get from the
initial state to the final state?
Lots of possibilities
Which is the correct way to get from
initial state to final state?
So how do kids learn the correct
principle?
Children are born with the
knowledge that language is
dependent on structure, not
linear order.
The End