“-- the optimal time to learn a second language is between age three and five or as soon thereafter as possible, and certainly before the onset of puberty.” -- Rosalie Porter
Critical Period Hypothesis
Theoretical Components of a Critical Period?
• Beginning and end points of the period.
• Qualitative difference inside and outside the period.
• Discontinuity at the end of the period.
• Robust to environmental variation inside the period.
Johnson & Newport (1989) Critical period effects in second-language learning: The influence of maturational state on the acquisition of English as a second language. Cognitive
Psychology, 21, 60-99.Pre-Puberty
2 4 6 8 10 12 14 16Age of Arrival
210
220
230
240
250
260
270
280
En
glis
h P
r of ic
ien
cy
Post-Puberty
10 20 30 40Age of Arrival
160
170
180
190
200
210
220
230
240
250
260
En
gli s
h P
r ofi c
ien
cy
r=-.87 r=-.16
Johnson & Newport, combined across age groups.
All Subjects
0 10 20 30 40Age of Arrival
150
200
250
300E
ng
lish
Pr o
f icie
ncy
What Kind of Theory is SES?
Hart & Risley
Hierarchical Structure of Language:Lenneberg’s Plan
Oral Proficiency
0 1 2 3 4 5 6 7GRADE
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
Pro
port
i on
of F
ull S
c ore
< 25% Free Lunch25-50% Free Lunch>50% Free Lunch
Poverty Level
Reading
0 1 2 3 4 5 6 7GRADE
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
Pr o
por t
ion
o f F
u ll S
c ore
Writing
0 1 2 3 4 5 6 7GRADE
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
Pr o
por t
ion
o f F
u ll S
c ore
Redesignation Rate
0 1 2 3 4 5 6 7GRADE
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
Pr o
por t
ion
o f F
u ll S
c ore
Figure 12. English development as a function of school poverty status. District A.
Figure 13. Norm-referenced English scores by parent educational level, District B. LEP student mean age equivalent score is represented by the colored portions of the bar; the white unshaded portion shows the expected age-equivalent for the norming population.
< High SchoolSome High SchoolHigh School or GEDBeyond High School
Parent Education
Oral Language
0 1 2 3 4 5 6GRADE
3
4
5
6
7
8
9
10
11
12A
ge E
q uiv
a len
t Sco
r e
0 1 2 3 4 5 63
6
9
12
Broad English Ability
0 1 2 3 4 5 6GRADE
3
4
5
6
7
8
9
10
11
12
Age
Eq u
iva l
ent S
cor e
0 1 2 3 4 5 63
6
9
12
Figure 16. Norm-referenced English writing scores by parent educational level, District B. LEP student mean age equivalent score is represented by the colored portions of the bar; the white unshaded portion shows the expected age-equivalent for the norming population.
< High SchoolSome High SchoolHigh School or GEDBeyond High School
Parent Education
Written Expression
0 1 2 3 4 5 6GRADE
3
4
5
6
7
8
9
10
11
12
Age
Eq u
iva l
ent S
cor e
0 1 2 3 4 5 63
6
9
12
Basic Writing Skills
0 1 2 3 4 5 6GRADE
3
4
5
6
7
8
9
10
11
12
Age
Eq u
iva l
ent S
cor e
0 1 2 3 4 5 63
6
9
12
Broad Written Language
0 1 2 3 4 5 6GRADE
3
4
5
6
7
8
9
10
11
12
Age
Eq u
iva l
ent S
cor e
0 1 2 3 4 5 63
6
9
12
Figure 13. Norm-referenced English scores by parent educational level, District B. LEP student mean age equivalent score is represented by the colored portions of the bar; the white unshaded portion shows the expected age-equivalent for the norming population.
< High SchoolSome High SchoolHigh School or GEDBeyond High School
Parent Education
Oral Language
0 1 2 3 4 5 6GRADE
3
4
5
6
7
8
9
10
11
12A
ge E
q uiv
a len
t Sco
r e
0 1 2 3 4 5 63
6
9
12
Broad English Ability
0 1 2 3 4 5 6GRADE
3
4
5
6
7
8
9
10
11
12
Age
Eq u
iva l
ent S
cor e
0 1 2 3 4 5 63
6
9
12