First Language Acquisition Theories : Linguistic/Innatist Theory
Theoretician(s)
•   Psammetichus
•   Lenneberg(critical period hypothesis)
•   Chomsky
•   Goldin-Meadow (deaf children's developing language)
•   Bickerton (pidgin--creaole)
•   Lightfoot 
Hypothesis: 
Many aspects of language development are preprogrammed in the individual and a child does not require explicit teaching or experience in order to acquire language. (Not "a" language) 
•   Language is autonomous (Modular)
•   There is Universal Principles (UG) which any natural human language obeys.
•   LAD
Evidence for the hypothesis
•   Studies with deaf 
•   Pidgin -- > creole studies
•   deficiency of input (Lightfoot)
•   Negative evidence and correction
REFERENCES
Gleason and Ratner (1998). Psycholinguistics. Second Edition. Forth Worth: Harcourt Brace Collage Publishers.
Keenan and Comrie (1977). "Noun phrase accessibility and universal grammar." Linguistic inquiry.8 (1), 63-99.