Gibson Ferguson Language Planning and Education Edinburgh ...

58 Language Planning and Education
spent on developing literacy skills in the L1 does not detract from attainment in
English. Indeed, the reverse may be true: the level of development of a pupil’s L1,
Cummins (2000, 2003) argues, is a strong predictor of their second language skills
and of their eventual academic attainment. This position is supported by Thomas
and Collier (1997: 15), whose data leads them to the strikingly strong conclusion
that:
The first predictor of long-term school success is cognitively complex on-grade
level academic instruction through students’ first language for as long as possible
(at least through grade 5 or 6) and cognitively complex on-grade level academic
instruction through the second language (English) for part of the day.
Evidence against the ‘time-on-task’ principle can be found in a range of studies.
For example, the Ramirez study (1991), though flawed in several respects, is at least
clear that pupils in early exit TBE programs and SEI programs performed comparably
in English language and reading by the end of grade 3. This, of course,
contradicts the ‘time-on-task’ principle’s prediction that there is a direct relation
between the amount of time allocated to instruction in and through English and
level of skills in the language.
Meanwhile, from the quite different context of the Turkish community in the
Netherlands, Verhoeven and Aarts (1998) report that the level of literacy attained in
L1 Turkish by primary-age Turkish pupils correlates positively with the level of
Dutch L2 literacy achieved, and that both are strongly related to ‘home stimulation’
(Verhoeven and Aarts 1998: 129).
Cummins’s linguistic interdependence hypothesis
Such findings, and those of many other studies (e.g. Williams 1996), both support
and are explained by the linguistic interdependence hypothesis, first proposed by
Cummins in a 1979 paper. This holds that:
to the extent that instruction through a minority language is effective in
developing academic proficiency in the minority language, transfer of this
proficiency to the majority language will occur given adequate exposure and
motivation to learn the majority language. (Cummins 1986 reprinted in Baker
and Hornberger 2001: 177)
A key underlying notion here, accounting for the transfer of academic literacyrelated
skills between languages, is the common underlying proficiency model of
bilingualism (CUP), which – in direct contrast with the SUP model (see above) –
postulates a ‘central processing system’ integrating and drawing on concepts and
linguistic abilities learnt in either, or both, L1 and L2. Cummins’s (2003: 63) helpful
analogy is with learning to tell the time: once pupils have learnt to tell the time in
their L1, they do not need to relearn the ‘telling-the-time’ concept in their second
language, only the vocabulary and grammar for doing so in an L2. Similarly with
academic-related literacy skills such as distinguishing the main idea from supporting
details: once learnt in the L1, the skills can transfer to the L2, or indeed vice-versa.