The ability to acquire the speech sounds of a second language has consistently been found to be constrained with increasing age of acquisition. Such constraints have been explained either through cross-linguistic influence in bilingual speakers or as the result of maturational declines in neural plasticity with age. Here, we disentangle these two explanations by investigating speech production in adults who were adopted from China to Sweden as toddlers, lost their first language, and became monolingual speakers of the second language. Although we find support for predictions based on models of bilingual language acquisition, these results cannot be explained by the bilingual status of the learners, indicating instead a long-term influence of early specialization for speech that is independent of bilingual language use. These findings are discussed in light of first-language interference and the theory of maturational constraints for language acquisition.

The critical period hypothesis (CPH) as an explanation of age effects on language learning has been a perennial source of contention in the field of second language acquisition (SLA). Although this hypothesis – which suggests that adult language learning is constrained by biological or maturational changes in the brain – has been based on the work of Eric Lenneberg (i.e. Biological Foundations of Language, 1967), it does not reflect Lenneberg's original biological theory of language. In this paper, the CPH is examined in light of a comprehensive review of Lenneberg's work and related disciplines. By outlining Lenneberg's notion of epigenesis in language development, it is argued that the CPH interpretation of the critical period notion that has long skewed the debate over age effects in SLA must be re-evaluated, and that any reference to “Lenneberg's CPH” can – and should – be abandoned.

A series of recent studies have shown that the once-assumed cognitive advantage of bilingualism finds little support in the evidence available to date. Surprisingly, however, the view that bilingualism incurs linguistic costs (the so-called lexical deficit) has not yet been subjected to the same degree of scrutiny, despite its centrality for our understanding of the human capacity for language. The current study implemented a comprehensive meta-analysis to address this gap. By analyzing 478 effect sizes from 130 studies on expressive vocabulary, we found that observed lexical deficits could not be attributed to bilingualism: Simultaneous bilinguals (who acquired both languages from birth) did not exhibit any lexical deficit, nor did sequential bilinguals (who acquired one language from birth and a second language after that) when tested in their mother tongue. Instead, systematic evidence for a lexical deficit was found among sequential bilinguals when tested in their second language, and more so for late than for early second language learners. This result suggests that a lexical deficit may be a phenomenon of second language acquisition rather than bilingualism per se.

In early childhood, the human brain goes through a period of tuning to native speech sounds but retains remarkable flexibility, allowing the learning of new languages throughout life. However, little is known about the stability over time of early neural specialization for speech and its influence on the formation of novel language representations. Here, we provide evidence that early international adoptees, who lose contact with their native language environment after adoption, retain enhanced sensitivity to a native lexical tone contrast more than 15 years after being adopted to Sweden from China, in the absence of any pretest familiarization with the stimuli. Changes in oscillatory brain activity showed how adoptees resort to inhibiting the processing of defunct phonological representations, rather than forgetting or replacing them with new ones. Furthermore, neurophysiological responses to native and nonnative contrasts were not negatively correlated, suggesting that native language retention does not interfere with the acquisition of adoptive phonology acquisition. These results suggest that early language experience provides strikingly resilient specialization for speech which is compensated for through inhibitory control mechanisms as learning conditions change later in life.

This paper endeavours to take stock of academic writing not merely as an activity that precedes publishing but as an art and a craft in its own right. We also draw attention to some of the conditions that affect writing in academia today, notably second language userhood in the production of text. In order to do that, we invoke the reasoning of British social anthropologist Tim Ingold, particularly his perspective on dwelling, skill, and the education of attention. From this emerges a view of academic writing as a practice founded in skill, developed through the dweller’s practical involvement with his or her everyday tasks and influenced by different constraints. Because no one is born a skilled writer, attentive dwelling lies at the core of the writer’s education of attention as a situated mode of perceptual engagement with the environments in which he or she dwells, be it through reading, co-authorship or textual response.

Why are we so afraid of making mistakes? Students in language classes, speakers of non-standard varieties, professionals working abroad – we all share the anxiety of dropping the ball. But where does this anxiety come from? Why do we perceive certain linguistic features as errors in the first place? Is there any inherent faultiness in such features, or is a language error arbitrary? And if it is arbitrary, are errors less real? In this discussion, Maria Khachaturyan, Maria Kuteeva and Svetlana Vetchinnikova zoom in on the social life of variation in language and its uneasy relationship with our normative ideas. After that, Gunnar Norrman and Dmitri Leontjev give their comments. The discussion closes with replies by the first three authors.

This thesis investigates the influence of age of acquisition on the long-term second language development of international adoptees. Because age of acquisition typically coincides with the onset of bilingualism, the study of maturational age effects in second language acquisition has been empirically and conceptually entangled with changes in language input and use. For international adoptees, however, because the adoptive language is acquired under similar linguistic conditions as non-adopted peers – albeit at a later age of acquisition – questions of age and second language acquisition can be investigated without confounding influences of bilingualism. Study I presents the theoretical argument that, because of the delay in acquisition, the language development of international adoptees should be regarded as a special case of second language acquisition. Furthermore, consistent with the contemporary study of second language acquisition, the effects of this delay should be investigated through ultimate attainment observed in adults. Study II shows that adults in Sweden who had been adopted from Spanish-speaking countries, and Spanish-Swedish bilinguals with the same age of acquisition (3-8 years), have greater difficulty in perceiving Swedish vowel distinctions that do not exist in Spanish compared to native Swedish speakers. This suggests that age of acquisition is a decisive factor for speech perception in a second language. In Study III, Chinese-Swedish adoptees are found to deviate from native Swedish speakers in their production of Swedish vowels that are phonologically identical in Chinese, but not in vowels that are distinctive in both languages. While these results are consistent with predictions based on assumptions of transfer and interference in bilingual speakers, they cannot be explained based on these premises. Instead, the results suggest that early language-specific experiences will affect the pronunciation of vowels in the second language regardless of whether the native language is in use or not. In Study IV, the neural underpinnings of the behavioral results are investigated electrophysiologically, using EEG. This study shows that adult adoptees retain increased neural sensitivity to a native Chinese lexical tone contrast without any exposure to the language for over 15 years. This is reflected in a fast neural response stemming from the auditory cortex and is indexed by the mismatch negativity event-related potential. This suggests that native language sensitivity is not only retained, but is continuously involved in the moment-to-moment processing of speech sounds. Neural oscillations furthermore reveal the involvement of inhibitory processes to attenuate this sensitivity. Finally, positive correlations between neural responses to the native and the adoptive language show that native language retention is not in itself an impediment for second language acquisition. The results from these three studies show how language-specific experiences lead to irreversible specialization in the brain, which will affect the long-term acquisition of a second language. This finding invites a re-evaluation of the hypothesis of a critical period for second language acquisition, based on the notions of probabilistic epigenesis and flexible behavioral adaptation following experience-based functional neural reorganization in early childhood.

Whereas the cognitive advantages brought about by bilingualism have recently been called into question, the so-called ‘lexical deficit’ in bilinguals is still largely taken for granted. Here, we argue that, in analogy with cognitive advantages, the lexical deficit does not apply across the board of bilinguals, but varies as a function of acquisition trajectory. To test this, we implement a novel methodological design, where the variables of bilingualism and first/second language status have been fully crossed in four different groups. While the results confirm effects of bilingualism on lexical proficiency and processing, they show more robust effects of age of acquisition. We conclude that the traditional view of the linguistic costs of bilingualism need to give way to a new understanding of lexical development in which age of acquisition is seen as a major determinant.

The linguistic development of internationally adopted children has been studied extensively for several decades. Whereas this research has mainly concerned toddlers and pre-school children during their first years after adoption, school-age children, and adolescents, there is currently scarce empirical evidence on the long-term linguistic development in adults with adoption background. While studies of infants and pre-school children generally show fast and positive short-term progress in linguistic development, medium-term studies (4–10 years after adoption) describe adoptees as still “lagging behind” their non-adopted peers. This chapter reviews the studies to date on long-term outcomes in the linguistic development of adoptees. What happens after more than ten years of exposure and into adulthood? From the review, we conclude that slight differences between adopted and non-adopted L1 speakers of a language often remain into adulthood. In addition, the limited evidence that exists to date suggests that adults who at a young age emigrated with their families to the L2 environment, and therefore continued to develop their L1, exhibit similar levels of L2 proficiency as internationally adopted adults. However, more research is required to further substantiate and generalize the conclusions that are made on the basis of our review.