Hoff, E.: Dual Language Exposure and Early Bilingual Development

Authors: Erika Hoff, Cynthia Core, Silvia Place, Rosario Rumiche, Melissa Señor, Marisol Parra
Institution: Florida Atlantic University
Publication Date: First published online 22 March 2011
Received: 13 January 2010
Revised: 21 July 2010
Accepted: 18 November 2010

Conflicting assertions exist on the influence of bilingualism on language development rates.
This study compares language development between high-SES samples of bilingual and monolingual children aged 1;10 to 2;6.
Monolingual children outperformed bilinguals in vocabulary and grammar when compared by language alone, but total vocabulary was similar.
Within the bilingual sample, vocabulary and grammar measures were related to the amount of input received in each language.

There is a growing population of children raised in bilingual homes, yet their language development path is not well understood.
Previous research (McCardle & Hoff, 2006) established that children exposed to two languages can learn them without confusion, contradicting earlier views.
Studies showed bilingual children distinguish their languages from infancy and learn two phonological systems, vocabularies, and grammars (Kováčs & Mehler, 2009).

It is unclear whether bilingual children acquire languages at the same pace as monolingual children.
The literature lacks normative data on what constitutes typical bilingual development (Genesee, 2006; Marchman et al., 2010).
Evidence suggests language acquisition is influenced by both biological factors and experience (Lidz, 2007; Tomasello, 2006).

The speed and ease of children learning two languages may suggest language acquisition is innate, particularly for grammar (Gleitman & Newport, 1995).
Bilingual children may require more time to learn two languages than monolinguals need for one, indicating that language learning is heavily dependent on experience and input (Gathercole & Hoff, 2007; Oller & Eilers, 2002).
Despite statistical risks linked to bilingualism regarding academic performance in the U.S., findings show cognitive advantages throughout the lifespan (Bialystok, 2005).

To identify the effects of early dual language exposure apart from confounding societal variables.
To provide normative descriptions of early bilingual development through direct comparisons to monolingual development.

The first bilingual studies focused on theory-based questions rather than providing normative data.
Generally, bilingual children achieve core milestones of language (first word, two-word combinations, 50-word vocabulary) at similar ages to monolinguals.

Sample Size: 47 bilingual children (Spanish-English) and 56 monolingual English children from South Florida.
Demographics: All were full-term, healthy at birth, with normal hearing.
Selection Criteria: Bilingual children had to be exposed to at least 10% of their input in the less-frequent language according to caregiver reports.
Gender Distribution: 25 male and 22 female bilinguals; 30 male and 26 female monolinguals.

Language development assessed at 1;10, 2;1, and 2;6 using:
1. English MacArthur-Bates Communicative Development Inventory (CDI) (Fenson et al., 1993)
2. Spanish equivalent (El Inventario del Desarrollo de Habilidades Comunicativas (IDHC)) (Jackson-Maldonado et al., 2003)

Raw vocabulary scores and grammatical development measures:
1. Word combination presence
2. Grammatical complexity score (based on utterances)
3. Mean Length of Utterance (MLU3)

Bilingual children had lower English vocabulary scores than monolinguals,
Vocabulary scores increased with age for both groups; however, significant differences were noted especially at age 2;6.

Total vocabulary scores (Spanish + English) showed no significant difference between groups, indicating both groups achieved similar vocabulary sizes overall.

Measurement of children producing word combinations.
At age 1;10, significant differences were noted with more monolinguals combining words.

Monolingual children had higher grammatical complexity and MLU compared to bilingual peers at all ages assessed.
The findings indicated a lower diversity and complexity in bilingual children's utterances, which increased over time but remained below monolingual levels.

Bilingual children generally lagged behind monolingual peers in acquiring vocabulary and grammar when a single language was assessed.
They performed comparably when evaluating total vocabulary and achievements of combining words in any language.
The degree of exposure to a language played a significant role in language achievement.

The results indicate bilingualism does introduce a delay in language acquisition paths, but this does not imply confusion or inability to learn languages.
Normative data can help educators develop effective curricula for bilingual children.
It suggests educators need to be cautious in interpreting language skills, as bilingual children may possess cognitive skills not reflected by their single-language abilities.

The study focused on a narrow age range (1;10 to 2;6) and utilized only caregiver-report measures, limiting comprehensive assessment advice for bilingual development.

Children acquiring two languages tend to lag behind those acquiring just one in those assessments, but they learn within the normal range of variation when considering both languages collectively.
Bilingual children can achieve significant vocabulary size similar to that of their monolingual peers when both languages are considered together.