Table of content
The Critical Period Hypothesis
The Sensitive Period Hypothesis
Implications of the CPH in SLA
L2 acquisition- the nature of the problem
The Fundamental Difference Hypothesis and the Role of UG
We started to introduce second language learning in elementary schools in Germany, because it is generally believed that younger learners are more successful in the acquisition of a new language in comparison to older students. On the other hand, we hear and read about adults who immigrated to a foreign country without any knowledge of the particular national language but after certain years, their proficiency turns out to be native-like, or in Joseph Conrad’s case, even above the average language proficiency. Considering first language acquisition the results are of different, less contradictory character. Individual cases like Genie, prove the fact that if the first language is not acquired up to a certain age, according to Francis (2007) this is age five, language acquisition becomes unacquirable. Hence, tragic cases like this call for the existence of a so-called Critical Period (CP).
Extending this hypothesis to Second Language Acquisition (SLA) the findings are less uniform and the linguistic debate remains unsolved for over 50 years.
“Given that maturation has the strong influence on second language outcomes that our review has indicated, it should come as no surprise that nativelike proficiency is unattainable for adults”(Hyltenstam & Abrahamsson 2003:578)
“The misconception that adults cannot master foreign languages is as widespread as it is erroneous” (Marinova- Tood, Marshall & Snow 2000:27)
These two quotes represent the dilemma of the debate. Is there a certain age limit for the acquisition of a second or a third language for learners? Are the same capacities available for older people as they were for young children? Can age certainly determine the success in SLA if there are found exceptions of native-like language proficiency among the older students in nearly every study?
This paper wants to research into the question of the existence of a Critical Period Hypothesis (CPH) in SLA. Further, since this theory was already introduced in the early 60’s, I will have a closer look at the modifications of the CPH, i.e. the Sensitive Period Hypothesis (SPH). By the help of taking some of the findings from different studies into account, I will try to answer the underlying question.
The Critical Period Hypothesis
First, it is necessary to clearly determine what is meant by the Critical Period Hypothesis. Due to the early foundation of this theory by Lennenberg and its high ressonance in language research, the CPH has been revised over and over.
Before Lenneberg, who is considered to be the founder of the CPH published his assumptions, the neuroscientists Penfield and Roberts already formulated an assumption in 1959. They concluded from their research that, “for the purpose of learning languages, the human brain becomes progressively stiff and rigid after the age of nine“ (Singleton 2005:271). Further they stated „when languages are taen up for the first time in the second decade of life, it is difficult... to achieve a god result... because it is unphysiological“ (Singleton 2005:271). Lenneberg researched into language recovery among aphasic patients, so people who have a comprised language ability due to injury or sickness. (Hyltenstam & Abrahamsson 2003:539) He then found out that if the disease occurred before puberty, a recovery of speech was likely. In contrast, the chances of complete recovery were relatively bad if aphasia occurred in adulthood. Based on these maintainments, Lenneberg proposed in 1967 concluded that “The primary acquisition of language is predicated upon a certain developmental stage which is quickly outgrown at the age of puberty. (Lenneberg 1967:142). He hence proposed an off- as well as an onset in his theory that the age of onset is age two. Puberty on the other hand is the critical period for the age of offset. The reason for this suggestion lies, due to Lenneberg, in the completition of hemispheric lateralization, which coincides with puberty.( Hyltenstam & Abrahamsson 2003:539).
The Sensitive Period Hypothesis
Lenneberg already suggested in his definition of the CPH the possible extension to second language acquisition (SLA) when he states,
Automatic acquisition form mere exposure to a given language seems to disappear, and foreign languages have to be taught and learned through a conscious and labored effort. Foreign accent cannot be overcome easily after puberty. However, a person can learn to communicate at the age of forty. This does not trouble our basic hypothesis. (Hyltenstam & Abrahamsson 2003: 540)
However, some researches maintain a modification of the original CPH into a sensitive period hypothesis (SPH) due to the results of further research that periods of special adaptability in the course of maturation are not always sharply set off or on, as the CPH maintains. Hence, the SPH proposes:
As in the critical period formulation, the special adaption is thought to occur during an early phase, but in this weaker formulation, the sensitivity does not disappear at a fixed point; instead it is thought to fade away over a longer period of time, perhaps covering later childhood puberty and adolescence. (Hyltenstam& Abrahamsson 2003:556)
Whereas the window of opportunity in the CPH then is of a well-defines character ( due to Lenneberge between 2-9), the SPH maintains a gradually declining period of opportunities over a longer time range. According to Hyltenstam and Abrahamson (2003) this period can range from later childhood to puberty until young adolescence.
Although both terms, SPH and CPH are often used interchangeably (Hyltenstam& Abrahamsson 2003:556), in the context of this paper, the formulation of the SPH is favoured. First, as Meisel points out, the CPH’s offset at around puberty is based on the process of lateralization, which is the functional specialization of two hemispheres of the human brain. However, recent research found out that this process happens much earlier (Meisel 2011) and secondly, “there does not seem to be a causal relationship between this process and the critical period effects in language acquisition.”(Meisel 2011:204).
Further, Meisel argues that due to the conflicting findings various studies contra the CPH are due to insufficiently precise definitions of the CPH (2011:204). Hence, he claims for a redefinition of the CPH, however without “affect[ing] the basic concept of the hypothesis.” (Meisel 2011:204) In his modification he explains in favour of a “cluster of sensitive phases”, in which the language acquisition device (LAD) is optimally prepared “to integrate new information into developing grammars” (Meisel 2011:205.) Additionally, he concludes that these phases are no categorical yes-no, nor on-off options, but, “each phase is characterized by an optimal period, followed by a gradual offset.”(2011) Hence, instead of a CPH, Meisel prefers the SPH, illustrated in the following schematic representation:
illustration not visible in this excerpt
(source: Meisel 2011:205)