Characteristics of Bilingual Households in South Florida Rosario Rumiche, Melissa Senor, and Erika H

1
Effects of Dual Language Exposure on Early
Lexical Growth
Erika Hoff
ehoff_at_fau.edu
BACKGROUND
RESULTS
Raw vocabulary scores for English-speaking
monolingual and Spanish-English bilingual
children at 22, 25, and 30 months based on the
CDI and IDHC
The present analyses of the bilingual development
of a sample of high SES toddlers were designed to
address two questions (1) Does dual language
input affect the rate of development in each
language? Case studies of successful bilingual
development and findings that bilingual children
score within the (very large) normal range of
variation suggest bilingualism need not slow
childrens rates of development in each language
(Pearson, 2008 Pearson, Fernández, Oller,
1993). In contrast, larger-scale studies of
children in immigrant families find that these
children exposed to two languages do acquire each
language more slowly than monolingual children
acquire one (Conboy Thal, 2006 Marchman,
Martínez-Sussman, Dale, 2004). (2) Is there a
trade off between languages in bilingual
development Do the two languages compete ? It is
typical to find a correlation close to zero
between levels of skill in bilingual childrens
two languages, which seems to reflect
independence rather than a trade off. However,
there is also good evidence that development in
each language is related to the proportion of
childrens input in each language, which suggests
at least some degree of trade off unless
bilingual children hear twice as much speech as
monolingual children.
It takes longer to learn two languages than one
When bilingual childrens vocabulary knowledge is
measured as their combined English and Spanish
vocabularies, the bilingually-developing children
were virtually identical to the monolingual
children in vocabulary size and rate of
vocabulary growth . When each language is
assessed separately, bilingually-developing
children show smaller vocabularies and slower
rates of growth over the period from 22 to 30
months . (Monolinguals English vocabularies
differed significantly from bilinguals in
English and Spanish, and there were an Age x
Language Group interactions indicating that the
gains over time in monolinguals English
vocabularies were greater than those in each
language taken alone for the bilinguals.) Input
effects create a trade off, but common influences
counteract the trade-off effect The bilingual
childrens Spanish and English vocabulary sizes
at 22 months were unrelated (r (n 39) .04 .
When the percent of childrens input that was in
English was held constant, the childrens
Spanish and English vocabulary sizes showed a
positive and significant correlation (r (df 36)
.29, p .04, one-tailed). The percent of input
in English was a strong predictor of the percent
of childrens total vocabularies that were
English words , r (n 39) .74, p lt .001,
onetailed.
METHOD
CONCLUSION
Thirty-nine children exposed to both Spanish and
English from birth and 51 monolingual
English-learning children participated. Both
groups were high SES and did not differ in
mothers or fathers mean education level.
Primary caregivers filled out the MacArthur-Bates
Communicative Development Inventories (and the
Inventario Desarollo de Habilidades Comunicativas
for the bilingual children) when their children
were 22, 25, and 30 months of age. A Home
Language Environment interview (validated against
diary records of childrens language exposure)
provided estimates of the proportion of Spanish
and English addressed to the bilingual children.
These findings suggest that at this early point
in lexical development, bilingual children learn
the same number of word forms as monolingual
children and that the distribution of bilingual
childrens word knowledge across their two
languages is proportional to their relative
amount of exposure to each language.
References Conboy, B. T., Thal, D. J. (2006).
Ties between the lexicon and grammar
Cross-sectional and longitudinal studies of
bilingual toddlers. Child Development, 77,
712-735. Fenson, L., Dale, P. S., Reznick, J.
S., Thal, D., Bates, E., Hartung, J. P., et al.
(1993). The MacArthur communicative development
inventories User's guide and technical manual.
San Diego Singular Publishing Group, Inc.
Jackson-Maldonado, D., Thal, D. J., Fenson, L.,
Marchman, V., Newton, T., Conboy, B. (2003). El
inventario del desarrollo de habilidades
comunicativas User's guide and technical manual.
Baltimore Paul H. Brookes. Marchman, V. A.,
Martínez-Sussmann, C., Dale, P. S. (2004). The
language-specific nature of grammatical
development Evidence from bilingual language
learners. Developmental Science, 7, 212-224.
Pearson, B. Z. (2008). Raising a bilingual
child. New York Living Language/Random House.
Pearson, B. Z., Fernandez, S. C., Oller, D. K.
(1993). Lexical development in bilingual infants
and toddlers Comparison to monolingual norms.
Language Learning, 43, 93-120. This research
was supported by NICHD grant HD054427 to Erika
Hoff.