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THE CRITICAL PERIOD HYPOTHESIS IN LANGUAGE LEARNING
Anorboyeva Zilola Avaz qizi
+998885994402
Student of Chirchik State Pedogogical University
Scientific advisor: Umirova Zamira A
ABSTRACT: According to the Critical Period Hypothesis (CPH), language
acquisition is most successful within a physiologically defined window of time. It is
thought that this phase ends around adolescence, at which point learning a language
becomes much more challenging and time-consuming. Since its initial formulation by
Eric Lenneberg in 1967, the hypothesis has served as a fundamental component of
research on language acquisition and psycholinguistics. There is conflicting but
generally positive evidence from a large number of research concerning first and
second language acquisition. For example, younger second-language learners
generally attain higher skill levels than adults, while children who are denied language
input early in life frequently fail to properly acquire language later. Recent research
using neuroimaging has also suggested age-related differences in brain plasticity
associated with language learning. This article explores both classical and
contemporary research on the topic, discusses counterarguments, and evaluates
implications for language education. The findings indicate that while age is a
significant factor, other variables—such as motivation, exposure, and context—also
play a crucial role in language acquisition success.
KEYWORDS: Critical period, language acquisition, second language, brain
plasticity, age effects, Lenneberg, psycholinguistics, bilingualism.
INTRODUCTION
Linguists, psychologists, and educators have all long been interested in the
process of language acquisition. The Critical Period Hypothesis (CPH), one of the
most hotly contested ideas in this area, postulates that the brain is particularly
responsive to language acquisition during a particular period of human development.
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The ability to learn a language with native-like competency drastically decreases after
puberty, which is thought to occur between early infancy and puberty (Lenneberg,
1967). Evidence from neuroscience and development supports this theory. The brain's
high degree of flexibility during childhood enables it to better process and adjust to
language input. This plasticity diminishes with age, making language acquisition more
challenging. This theory is supported by numerous case studies. For instance, studies
on children who experienced social isolation and lack of language exposure in their
early years (such as Genie, a socially isolated toddler) reveal that even with intense
training, these children had difficulty learning grammatical structures later in life.
Additionally, second language acquisition studies provide further evidence.
Children who begin learning a second language before the age of 7 often develop
native-like fluency, whereas adults rarely reach such levels. However, it is important
to note that the CPH is not universally accepted without critique. Some researchers
argue that success in language learning is not solely dependent on age but also
influenced by factors such as motivation, learning environment, and exposure. This
article aims to examine key findings from both classical and modern studies, evaluate
the scientific merit of the hypothesis, and discuss its implications for language
education policies and teaching methodologies.
RESULTS AND DISCUSSION
Studies on the Critical Period Hypothesis have shown a variety of results that
both confirm and refute the hypothesis. Eric Lenneberg first proposed this theory in
1967 after noticing that children who had brain injuries prior to puberty frequently
recovered their language skills more completely than those who had injuries after
puberty. This established the foundation for the idea that age-related biological
limitations affect language acquisition.
Subsequent research has provided robust
evidence for age-related effects, particularly in pronunciation and grammar. Johnson
and Newport’s (1989) seminal study on Korean and Chinese immigrants to the United
States found that age of arrival was a strong predictor of English proficiency. Those
who arrived before age seven performed similarly to native speakers, while
performance declined with increasing age of arrival. Neuroscientific studies further
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support the CPH. Functional MRI scans show that early bilinguals activate both
languages in overlapping regions of the brain, whereas late bilinguals often engage
distinct neural areas, suggesting differences in how the brain processes language based
on age of acquisition. This aligns with the notion that brain plasticity diminishes with
age, limiting the capacity for native-like learning after puberty.
There are some notable outliers, though. High competency levels have been
attained by certain adult learners, particularly in immersion settings or with strong
motivation. The significance of understandable input as people age is emphasized by
Krashen's (1982) input theory. Furthermore, according to Birdsong (1999), in certain
situations, individual characteristics including working memory, ability, and affective
factors might outweigh the impact of age. These mixed findings suggest that while
there is strong support for a critical period, especially regarding pronunciation and
syntax, the hypothesis may not fully account for the complexities of language learning.
It is more accurate to describe age as a significant but not exclusive factor. Therefore,
modern interpretations often refer to a "sensitive period" rather than a rigid "critical"
period, allowing for variability in language learning success across the lifespan.
CONCLUSION
The critical period hypothesis is still a key idea in the study of language
acquisition, especially when comparing how easy it is for toddlers and adults to learn
a language. Numerous study findings from studies in neurology, psychology, and
second languages support the idea. All of these show that language learning is more
successful and natural in the early phases of development, particularly prior to puberty.
However, a growing div of evidence indicates that language learning does not
become impossible after this period—it becomes more challenging and may require
different learning strategies. Factors such as motivation, learning environment,
language input, and cognitive differences play crucial roles in determining the success
of language learning in adults. While the biological foundation of the hypothesis is
compelling, educators and policymakers must adopt a more flexible interpretation.
Emphasizing early language exposure remains beneficial, but adult learners should not
be discouraged. With appropriate support, they can achieve high levels of fluency.
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Ultimately, a comprehensive understanding of the Critical Period Hypothesis allows
for better-informed decisions in both educational planning and second language
instruction.
REFERENCES
1.
Lenneberg, E. H. (1967). Biological Foundations of Language. New York:
Wiley.
2.
Johnson, J. S., & Newport, E. L. (1989). Critical period effects in second
language learning: The influence of maturational state on the acquisition of English as
a second language. Cognitive Psychology, 21(1), 60–99.
3.
Krashen, S. D. (1982). Principles and Practice in Second Language Acquisition.
Oxford: Pergamon.
4.
Birdsong, D. (1999). Second language acquisition and the Critical Period
Hypothesis. Lawrence Erlbaum Associates.
5.
Singleton, D., & Ryan, L. (2004). Language Acquisition: The Age Factor.
Multilingual Matters.
6.
DeKeyser, R. M. (2000). The robustness of critical period effects in second
language acquisition. Studies in Second Language Acquisition, 22(4), 499–533.
