delayed speech in bilingual children?

[Fred Genesee]

Monika:

The cumulative evidence culled from a number of studies which have looked at
early developmental milestones in children acquiring two languages
simultaneously indicates that first words appear in bilingual children within
the same age range as found for children learning the respective languages
monolingually. Viewed differently, there is no evidence that bilingual
children
produce first words later than monolingual children. All of this evidence
comes
from single case studies or small sample sizes and, thus, cannot be taken as
normative, strictly speaking. The one exception may be research by Barabara
Pearson who examined a relatively large group of Spanish-English bilinguals in
Florida. Research in our lab, and in other's, has also found that basic
syntactic patterns emerge in bilingual children at the same time (or within
the
same age range) as that found for monolingual comparison children, supporting
the notion that exposure to two languages does not retard the emergence of
critical milestones in acquisition. I recently did a summary of research that
mentions the emergence of major milestones in the acquisition of bilingual
children --I would be happy to send you a copy of this chapter  if you are
interested.

With respect to your second question, this is much more complex, and I am not
aware of research that addresses this question directly. Nor, am I aware of
how
you could actually address it directly. There is some evidence that is
relevant
to this issue and it suggests that bilingual children who experience delays or
other difficulties with language do so for underlying reasons that are not
related to bilingual exposure. For example, Johanne Paradis, Martha Crago
and I
reported data at last year's BU conference showing that bilingual
English-French children with SLI demonstrate the same pattern of impairment as
monolingual children with SLI learning the same languages and, of particular
relevance to your question, the extent of their impairment is the same as that
of  monolingual comparison children; in other words, it does not appear that
their bilingualism has exacerbated their impairment, suggesting that it is not
their bilingualism that is the problem Rather, it follows from these data that
there is some fundamental impairment in the "language acquisition device" and
this impacts the acquisition of any language (be it one or two).

Of course, bilingual children can have very different patterns of exposure to
their respective languages -- with some children getting equal and consistent
exposure to both languages and others getting consistent and rich exposure to
one but inconsistent and thus somewhat reduced exposure to the other. In such
cases, one might well imagine a delay in the emergence of first words in the
language with reduced, inconsistent exposure. Anecdotally, we have found that
young bilingual children who experience such input do not appear to be
developing bilingually; often  we have had to drop these children from our
study because they did not give sufficient evidence in one of their languages
that it was, in fact, developing beyond some basic comprehension skills; their
production skills were minimal. But, this is the exception and is invariably
linked to unusual exposure to one of their languages. You could say that it is
their bilingualism that is causing the delay; but, this is trur only in the
limited sense that bilingual exposure that is irregular and infrequent causes
delay. In principle, this is true for monolingual children as well. It is
probably the case that monolingual children get far more input than they need
in order to exhibit normal patterns of acquisition (including the emergence of
fundamental milestones).  Neverthelesss, there is undoubtedly some level of
exposure below which "normal" patterns of development will not occur even in
monolingual children.  In other words, a significant reduction in exposure to
language in the case of monolingual children (below some critical level) is
also likely to lead to delayed development.

While we are a long way from fully understanding bilingual acquisition, the
picture that is emerging is that acquisition of two languages is just as
normal
as the acquisition of one, given appropriate exposure. Bilingual demonstrate
the same patterns of acquisition at the same time as monolinguals. There
are of
course differences between monolingual and bilingual children -- such as
code-mixing and perhaps interactions between their developing  grammatical
systems and these are the topic of current work in the field.

Fred Genesee

At 04:35 PM 3/29/01 -0600, Monika Pawlowska wrote:
>Dear Info-CHILDES,
>
>I am looking for information about the following two questions:
>
>1. When do children raised in a bilingual home start producing their
>first words and how do they compare to children raised in monolingual
>families?
>
>2. Is there any way to tell whether delayed speech is caused by being
>exposed to two languages at the same time, or whether it is a sign of a
>deeper problem?
>
>I would appreciate references to any relevant studies.
>
>Thank you
>
>Monika Pawlowska
>
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