Physics states that “two objects cannot occupy the same space simultaneously”. Can two languages occupy the same space simultaneously? Do brain cells compete to keep their language? Do multiple languages increase or diminish our ability to learn? In an attempt to answer some of these questions, I will discuss briefly some of the cognitive theories related to bilingualism.
First, the Balance Theory promoted the idea that two languages had to exist in balance. If the careful balance between the first language (L1) and the second language (L2) shifted in favor of one language the other would suffer. Two languages could not occupy the same space without taking space from the other. Either the L1 would decrease due to an increase in L2 or vice versa. Cummings characterized this belief as the Separate Underlying Proficiency Model of Bilingualism (SUP).
On the other hand, the Common Underlying Proficiency Model of Bilingualism (CUP) is an alternative to the SUP model. In this model the external characteristics of L1 and L2 are different but the internal underlying processes of comprehension are the same.
While speech, grammar, and writing may be completely different in L1 and L2, the process by which we understand and internalize concepts lie in the same area.
Baker (1996) states that the CUP model operates under the following six tenets:
1. There is one integrated source of thought regardless of language.
2. People have the capacity to store and function in two or more languages with ease.
3. Information processing and educational skills may be developed through two languages with the same success as one language.
4. The language of instruction must be sufficiently well developed for the student to manage the challenges presented in the classroom.
5. Learning language skills in either L1 or L2 helps the whole cognitive system grow, as long as both are sufficiently developed.
6. Academic and cognitive performance depend on both languages functioning at full capability.
In addition to SUP and CUP models, The Thresholds Theory, proposed by Cummings, Toukomaa, and Skutnabb-Kangas, attempts to explain the relationship between cognition and bilingualism. There are two upper limits in this theory. Each one is a level of bilingual competence with their set of negative or positive consequences. Visualize a three story house with ladders representing L1 and L2 on either side. Each floor of the house represents different competences of bilingualism with their positive or negative consequences. The ceilings represent the two thresholds to surpass in the theory. Once students break through the second threshold and reach the third story, they can easily compete with peers in both L1 and L2. Curriculum may be taught in either language and the student would be able to grasp the concepts easily. These fully bilingual students usually surpass monolingual students in their cognitive development.
Have you noticed that some students speak L2 very well, but fail to perform in the classroom? Cumming's Developmental Interdependence hypothesis explains this phenomenon. It states that a child’s ability in L2 depends on the competence achieved in L1. A distinction between skills required to communicate in everyday life and those required to succeed in the academic arena was created.
Cummings called the ability to hold simple, everyday life conversations as the basic interpersonal communicative skills (BICS). He labeled the proficiency required to meet the academic demands in the classroom the cognitive/academic language proficiency (CALP). BICS are highly contextual and rely on non-verbal cues. CALPs relate to higher order thinking skills and are neither context embedded nor concrete. The student cannot rely on body language or contextual clues in order to perform at the CALP level. The student must be aware of the subtle nuances of language and must be able to discern between idioms, accents, and unusual usage of seemingly common words. Conversational proficiency usually precedes cognitive and academic proficiency. Students may be able to hold conversations easily in L1 and L2, fooling teachers into thinking that the student is fully bilingual, but not be able to perform adequately in the context reduced, cognitive demanding academic environment. Thus our jobs as teachers is to foster the development of L2 at the CALP level.
The different theories presented suggest that in fact two, or even more, languages can occupy the same space. Not only can they reside within the brain, but the languages can feed off each other to help the multilingual person reach a deeper meaning and understanding of the world.
Baker, Colin. (1996). Cognitive theories of bilingualism and the curriculum. Foundations of bilingual education. (pp. 145-161). Clevedon: Multilingual Matters, LTD