You are viewing a free preview of this lesson.
Subscribe to unlock all 10 lessons in this course and every other course on LearningBro.
More than half the world's population uses more than one language, so bilingualism and multilingualism are the global norm, not the exception — yet much classic child-language research focused on monolingual children, and a persistent deficit framing (that bilingualism "confuses" children or splits their resources) has had to be actively dismantled. This lesson examines how children acquire two or more languages, the cognitive and educational implications, and the major theories (especially Cummins and Lambert) and debates. Within the AQA Children's Language Development (0–11 years) topic, bilingualism most often appears as a strand of a wider data response: a Section B transcript may show a bilingual child code-switching, and a strong candidate must read this as competence, not deficiency, and bring the relevant frameworks to bear.
Key Definition: Bilingualism — the ability to use two languages in everyday life. It is best understood as a continuum rather than an all-or-nothing state, ranging from balanced bilinguals (broadly equal proficiency) to dominant bilinguals (stronger in one). Multilingualism extends this to three or more languages. Importantly, bilingual ability is usually domain-distributed — a speaker may control home/family vocabulary in one language and school/academic vocabulary in the other.
Because bilingualism is not a simple either/or category, several distinctions are essential for analysis:
| Type | Description | Example |
|---|---|---|
| Simultaneous bilingualism | Two languages acquired from birth (typically before age 3) | A child whose mother speaks English and father speaks Polish from day one |
| Sequential (consecutive) bilingualism | An L1 is established first; an L2 begins later | A child who speaks Urdu at home and begins English on starting school at 4 |
| Balanced bilingualism | Roughly equal proficiency across contexts | Relatively rare; most bilinguals are dominant in one language |
| Dominant bilingualism | Greater proficiency in one language | Common; the dominant language often reflects the community/school language |
| Receptive (passive) bilingualism | Understands an L2 but does not (or chooses not to) produce it | A child who understands grandparents' language but always replies in English |
A crucial practical implication: the monolingual yardstick is the wrong measure. Comparing a bilingual child's vocabulary in one of their languages against a monolingual norm will make them look "behind", when in fact their total conceptual–linguistic resource, spread across two languages, is typically age-appropriate or larger. Much historical misjudgement of bilingual children stems from this single methodological error.
Children exposed to two languages from birth pass through broadly the same milestones as monolinguals — babbling, first words around 12 months, the two-word stage, telegraphic speech — though they may take a little longer to build vocabulary within each individual language (while their combined vocabulary is comparable). The central historical debate concerns when the two systems separate.
| Position | Claim | Key researchers |
|---|---|---|
| Unitary (single) system hypothesis | The bilingual child at first has one fused system and only later separates the two languages, via an undifferentiated → lexical-differentiation → full-differentiation sequence | Volterra and Taeschner (1978) |
| Dual (separate) systems hypothesis | The child differentiates the two languages from the very beginning, even though they sometimes mix elements; mixing reflects pragmatic/lexical-gap choices, not confusion | Genesee (1989); De Houwer (1990) |
The earlier Volterra and Taeschner (1978) three-stage model (an initial fused lexicon, then separated vocabularies but shared grammar, then full separation) has been largely superseded. More recent evidence (Genesee, 1989; De Houwer, 1990) shows even very young bilinguals use their languages differentially with different interlocutors — addressing one parent in one language and the other parent in the other — which implies separate systems and sensitive pragmatic control rather than a single confused store.
Key Definition: Simultaneous bilingualism — acquisition of two languages from birth (or before ~3). Such children reach developmental milestones comparable to monolinguals; current evidence favours the view that they differentiate their two languages from very early, contrary to the older "single fused system" hypothesis.
The most visible feature of bilingual use is code-switching — alternating between languages within a conversation, a turn, or even a single sentence.
| Term | Description | Example |
|---|---|---|
| Code-switching | Alternation at sentence boundaries or between turns | "I'm going to the shop. Quieres algo?" (Do you want anything?) |
| Code-mixing | Mixing elements within a single sentence | "Can you pass me the lait?" (lait = milk, French) |
Code-switching is emphatically not a sign of confusion or deficiency; it is a rule-governed, socially sensitive skill that requires competence in both languages. Researchers have identified consistent communicative functions, including:
The fact that bilingual children switch appropriately for the listener — using one language with a monolingual grandparent and another at school — is itself evidence of pragmatic and metalinguistic sophistication, and it is a gift in a Section B transcript: it lets you argue against the deficit model directly from the data.
Key Definition: Code-switching — rule-governed alternation between two or more languages within a conversation, turn or sentence. Far from indicating confusion, it demonstrates competence in both languages and finely tuned sensitivity to audience, topic and identity.
Jim Cummins (1979, 1984) produced the frameworks most relevant to bilingual children in education, and they are the highest-value references for this topic.
| Concept | Full name | Description | Example |
|---|---|---|---|
| BICS | Basic Interpersonal Communication Skills | Everyday conversational fluency — context-embedded, cognitively undemanding | Chatting in the playground; ordering food |
| CALP | Cognitive Academic Language Proficiency | The decontextualised language of academic learning — context-reduced, cognitively demanding | Reading a science textbook; writing an essay; following a lecture |
Cummins observed that bilingual children typically develop BICS relatively quickly (often within ~1–3 years of exposure) but take much longer — commonly cited as around 5–7 years — to develop CALP in the new language. The educational consequence is significant and frequently misunderstood:
Key Definition: BICS and CALP (Cummins, 1979) — the distinction between Basic Interpersonal Communication Skills (quick-to-acquire conversational fluency) and Cognitive Academic Language Proficiency (slower-to-acquire academic language). The gap between them explains why apparently fluent bilingual children may underperform academically if support is withdrawn too soon.
Cummins' threshold hypothesis proposes that the cognitive consequences of bilingualism depend on the level of competence reached in the two languages:
| Level | Description | Cognitive effect |
|---|---|---|
| Below the lower threshold | Low proficiency in both languages | Possible negative cognitive effects |
| Between the thresholds | Age-appropriate in one language but not the other | Broadly neutral — neither positive nor negative |
| Above the upper threshold | Age-appropriate in both languages | Positive effects — enhanced metalinguistic awareness and cognitive flexibility |
The model thus reframes the old "is bilingualism good or bad?" question: it is the degree of bilingual competence, shaped heavily by social and educational support, that determines the outcome — not bilingualism in itself.
Cummins' interdependence hypothesis, often pictured as the Common Underlying Proficiency (CUP) model, argues that:
The CUP model is sometimes contrasted with a (rejected) Separate Underlying Proficiency view that imagined the two languages as competing for fixed mental "space"; CUP's evidence-based claim is that strengthening either language strengthens the shared base.
Wallace Lambert (1974) drew a decisive distinction that frames the whole social politics of bilingual education:
| Type | Description | Typical outcome |
|---|---|---|
| Additive bilingualism | The L2 is added while the L1 is maintained and valued; the child gains a language without losing one | Associated with the cognitive and academic benefits of bilingualism |
| Subtractive bilingualism | The L2 is acquired at the expense of the L1, often because the L1 is undervalued by school/society and is gradually replaced | Associated with loss of the home language and poorer outcomes |
Key Definition: Additive vs subtractive bilingualism (Lambert, 1974) — additive bilingualism adds a second language while preserving and valuing the first (linked to bilingualism's benefits); subtractive bilingualism replaces the first language with the second (linked to home-language loss). Whether a child's bilingualism is additive or subtractive is largely determined by the social value attached to each language.
This distinction sits neatly alongside Cummins: additive contexts are precisely those that let children climb above the upper threshold and exploit the CUP, whereas subtractive contexts push children below the lower threshold and toward attrition.
Research has documented several cognitive and linguistic advantages, while recent debate has tempered some stronger claims:
| Advantage | Research evidence |
|---|---|
| Enhanced metalinguistic awareness | Bilingual children reflect on language as a system more readily than monolinguals (Bialystok, 2001) — the foundation of the threshold model's "positive effects" |
| Greater cognitive flexibility | Advantages on tasks requiring switching between mental sets (Bialystok and Martin, 2004) |
| Stronger executive function | Reported advantages in attention control, inhibition and working memory (Bialystok, 2009) — though the size and replicability of the "bilingual advantage" are now actively debated |
| Increased cultural and intercultural awareness | Access to two cultural frames enhances perspective-taking |
| Possible cognitive-reserve effects in ageing | Some studies associate lifelong bilingualism with a later onset of dementia symptoms (Bialystok, Craik and Freedman, 2007) — correlational and contested |
The historical turning point was Peal and Lambert (1962), whose Montreal study found bilingual children outperforming monolinguals on a range of measures, overturning earlier work that had "shown" bilingual deficits but had failed to control for socio-economic status and had tested children in their weaker language. The methodological lesson — control for confounds and don't test in the weaker language — is itself examinable.
The concept of semilingualism (or double semilingualism) — that some bilingual children fail to reach full competence in either language — is highly controversial.
Educational systems handle bilingual children very differently, and the additive/subtractive distinction predicts the outcomes well:
| Approach | Description | Evaluation |
|---|---|---|
| Submersion ("sink or swim") | Placed in mainstream L2-only classes with no support; L1 ignored | Often subtractive; underachievement and L1 loss |
| Transitional bilingual education | Initial teaching in L1, shifting to L2 over time | Eases early access but can become subtractive (L1 attrition) |
| Maintenance / heritage-language programmes | Both languages taught throughout, aiming for biliteracy | Additive; supports the CUP; good academic outcomes |
| Immersion (e.g. Canadian French immersion) | Taught largely in L2, with L1 secure at home and in society | Additive for majority-language children; effective L2 gains without L1 loss |
| Dual-language / two-way immersion | L1 and L2 speakers educated together in both languages | Strongly additive; benefits for all; robust evidence of gains |
Key Definition: Language attrition — the partial or total loss of a language through disuse, typically when a speaker is immersed in a different-language environment. It commonly affects the home language (L1) of bilingual children when school and society do not support or value it — the lived mechanism of subtractive bilingualism.
Factors driving attrition include schooling exclusively in L2, peer pressure to use the majority language, limited L1 exposure beyond the home, and negative societal attitudes toward the L1. Attrition matters not only for family and cultural continuity but, via Cummins, for academic outcomes — because eroding the L1 weakens the common underlying base on which L2 literacy also draws.
Whereas simultaneous bilinguals build two systems from the start, sequential (consecutive) bilinguals already have an established L1 when they meet the L2 — typically on entering nursery or school. Their route through the L2 looks rather different, and a frequently cited description (associated with Patton Tabors) identifies a recognisable sequence:
Subscribe to continue reading
Get full access to this lesson and all 10 lessons in this course.