Overregulation Overgeneralization

[Overlapping speech sounds.]

[Intro music.]

Teacher: What did your person
do before they went to school?

Girl: They drived to school.

Teacher: They did what?

Girl: They drived.

Teacher: Drived to school?

Man 1: Children are designed
in such a way to look for rules

in the data around them.

They're very good at finding
rules that are there and

they're very good at even
overgeneralizing these rules.

What's going overhead?

Girl 2: Geeses

Man 2: We find everywhere that
children take the irregular

patterns of their language and try
to make them as regular as possible.

So just like English speaking children
will say things like "two foots" instead

of "two feet" or "it breaked" instead of
"it broke", children in every language

will fill in the missing gaps, fill in the
errors, and try to make the language

follow a system.

They have a clear sense of system.

Woman: We find that deaf children of
deaf parents begin to learn first words

and then begin to learn the grammar
at the same age as hearing children

learning a spoken language.

And is so doing, we find they make the
same kinds of mistakes or overgeneralizations,

showing that in fact they're extracting out the
rules of the language.

So if you want to sign, this is "duck."
If you want to sign "two ducks", you'd

probably say "two duck."
But a deaf baby instead will overgeneralize

and sign "two ducks" like this.

Woman 2: So they are looking for some deep
principles. They follow these deep principles.

If the language chooses to violate those
principles now and then, the children

seem to say, "So much the worse for the
language."

Teacher: Ruth says that they're foots.
I say that they're feet.

What do you say they are?
Girl: I say they are foots.