1. CRITICAL PERIOD
HYPOTHESIS

2. OUTLINE
I. Critical Period Hypothesis (CPH)
A. What is CPH?
a. Historical Background
B. Further Supportive Studies
a. Brain Lateralization
b. Genie and Victor
C.Effects of CPH on Different Areas
D. CPH for Sign Language
E. Different ideas
Conclusion

3. WHAT IS CPH?
 The critical period hypothesis is the
subject of long standing debate in linguistics
and language acquisition over the extent to
which the ability to acquire language is
biologically linked to age.

4.  If language input does not occur until after
this time, the individual will never achieve a
full command of language especially
grammatical systems.

5. HISTORICAL BACKGROUND
Wilder Penfield and co-author Lamar
Roberts (1959)
- The first to introduce the CPH
- The main study is neuroscience of language
- Up to the age of 9 can learn multiple languages

6. Eric Lenneberg (1967)
- Studied the CPH in his book
“Biological foundations of
language”.
- Children having a certain
amount of time to acquire a
language
- Until the age of 13 language is
present in both hemisphere.

7. Noam Chomsky
- Children are born with an inherited ability to
learn any human language
- Every child has a “language acquisiton device
(LAD)”

8. FURTHER SUPPORTIVE STUDIES
- In the early 1960s, Chomsky had launched
his idea that humans have an innate
language capacity and around the same
time, a neuropsychologist, Eric Lenneberg,
accepting Chomsky’s claim.
- Lenneberg’s reasoning was based on the
notion of lateralization.

9. SAMPLES OF FERAL CHILDREN
- A celebrated case is that of Victor, “the wild
boy of Aveyron”, who was found in 1798.
- In 1970 a child called Genie in the scientific
reports was discovered.
GenieVictor

10. GENIE
 She was locked away from
normal civilization and was
undeveloped physically and
emotionally.
 Genie was an infant who
trapped in a 13 year old
body, because she could only
make infant like sounds and
no words or sentences.

11.  Genie full stomach.
 Father take piece
wood. Hit. Cry.
 Want milk.
 Genie bad cold live
father house.

12. EFFECTS OF CPH ON DIFFERENT
AREAS
Phonology
 There is a narrow period for the
acquisition of segments of a language. (0-5
years) This period is very important for
the exposure to audial input.

13. Syntax and Grammar
 Syntax and Grammar are also acquired in a specific
period.(0-12 years)
 As Genie completed her childhood without having been
exposed to her mother tongue, she couldn’t produce
grammatically correct sentences.

14. Semantics
 Semantics is not much effected by the
critical age. Although Genie couldnt’t
acquire the syntax, She was able to learn
some vocabularies of her language.

15. CPH FOR SIGN LANGUAGE
 It is crucial to learn sign language as early as
possible. (From birth to 6 years)

16. DIFFERENT IDEAS
Various theorist have claimed different
ages for the termination of the CPH:
 Krashen (1973)‐ 5 years
 Pinker (1994)‐ 6 years
 Lenneberg (1967)‐ 12 years
 Johnson & Newport (1989)‐ 15 years

17. Another sample
- Older is better.
- Learning is linked to the mental abilities.

19. Emine ÖZKURT
Esra TAMER
Habip TÜREYEN
Tarık YÜTÜK

20. REFERENCES:
• http://www.slideshare.net/chitra101/my-critical-
period-hypothesis-cph
• http://claws.wcu.edu/cbcunningham1/cphpp.pdf
• http://www.wisegeek.com/what-is-the-critical-period-
hypothesis.htm
• http://www.academia.edu/290567/Critical_Period_Hyp
othesis_for_Second_Language_Acquisition_A_Review_
of_the_Literature
• http://journals.tc-
library.org/index.php/tesol/article/viewFile/462/278