This lecture is about language and its development and social development. We start with a characterization of language, what its major features are, which of them are centrally important and how human language differs from animal communication (animal signal systems). One role of language is that it allows us to build a cumulative culture (where each generation does not have to start all over again from the beginning because cultural knowledge can be transmitted) is examined in support of the view that it is language that really distinguishes us from animals--even smart ones who have good signalling systems! The ability of language to produce (and understand) an infinite array of assertions (including creative--brand new--ones) together with its ability to describe distant (in time and place) things (displacement) are particularly important in this regard. We will also discuss attempts to teach animals human languages. The slides can be found here. Please note that they have been changed from Tuesday's originally posted set.

• Language can be viewed as a heirarchy.

1. Phonology (unit is the phoneme)
2. Semantics (unit is the morpheme)
3. Syntax (allows infinite array of utterances
4. Pragmatics (rules of usage in a given culture

• Language Development

1. It starts early, (infant "conversations" with caregiver, babbling).
2. Then on to 1-word and 2-word stages.
3. Then proliferation and rapid acquistion of syntax and vocabulary explosion.
4. Issue of holophrastic and telegraphic speech where the child intends more than they can say.
5. The aspects of language that are best described as exhibiting a critical period in their development will be discussed. These include the necessity of learning a first language sometime fairly early in life if you are ever going to be able to learn a syntactic language, and the development of phonology (speaking a new language accent free) will be examined as two aspects of language to which a critical period in their development seems to exist. We will also discuss the relation between language and thought.