Reviving long-forgotten knowledge


For most of us, the languages that we are — primarily or exclusively —exposed to as a child, becomes our native languages as an adult. This, of course, does not come as a surprise, nor as breaking news. It is almost always the case that, from the moment children are born until they start school, they are raised in a natural environment where they are constantly in interaction with the languages of their parents, and, if different, the languages of their society. Thus, their birth languages as infants become their dominant languages as adults. However, for some children, namely adoptees, this is not the case.

Ever since globalisation established itself in the world, a huge increase in the number of adoptions has been observed. Either for financial or other reasons, many children — especially from Asian and African countries — are adopted and raised in a different culture and linguistic environment than the one they came from. Moreover, the adoption often takes place before the age of 5-6 years. This means that exposure to their birth languages is abruptly interrupted before the process of acquisition is sufficiently completed.

As a result, the adopted children — also referred to as international adoptees — become immersed into a new linguistic environment, exposed to the language of their adoptive parents, while still young. This so-called adoptive language will eventually become their new native language, or as some might call it, their second first language. The case of adopted children allows us to explore language attrition and retention. Attrition refers to the process of losing certain aspects of the native language, whereas retention is about the ability to maintain them throughout time and despite any emerging obstacles. Thus, an intriguing question arises: to what extent do adopted children retain knowledge of their birth language, if at all?

Many adoptees lose the ability to speak their birth language. But does this mean that they retain no knowledge of it at all? To answer this question, studies have looked at whether adult international adoptees can identify certain phonemic contrasts — a minimal difference in pronunciation that leads to different meanings — found in their birth language but not in the adoptive language. For example, in Korean there is a meaningful difference between a p-sound with a burst of breath, (“pʰul” means grass) and a p-sound without a burst of breath (“pul” means fire). In a language like Swedish, it doesn’t matter if you produce a p-sound or a pʰ-sound; it does not result in different words with different meanings.

Whether a sound difference is meaningful has a strange effect on how we perceive the sounds. Because the difference is meaningful in Korean, adult Korean speakers can perceive the p-pʰ distinction. They quite clearly hear the two different sounds. However, speakers of languages in which this p-pʰ distinction is not meaningful usually cannot. Or if they can, they cannot do it effortlessly.

But do adopted children born in Korea have the ability to recognise these phonetic differences when they are absent in their adoptive language? In other words, do children retain the ability to perceive these sound differences even though they haven’t heard any Korean for years? Researchers found that Korean adoptees in Sweden (Swedish does not have the p-pʰ distinction) performed better when carrying out tasks that involved perceiving and recognising such Korean-specific sound contrasts after a short period of training and re-exposure to Korean, compared to individuals born in Sweden who had no prior exposure to Korean, but went through the same training period. What does that mean?

First, the fact that perceptual knowledge of a language can somehow be retained even after a limited amount of exposure shows how important this very early exposure is, no matter how brief it might have been. Research in the field of language acquisition can greatly benefit from such findings. For instance, they can help us unravel underlying factors and processes that can explain why and how these very early and sometimes very brief experiences with a language have such long-lasting effects on people’s language system and their ability to distinguish sounds. We can also explore whether these factors are specific to language or related to broader, more general cognitive skills. For instance, with regard to memory, a mechanism that is not specific to language, it seems that our memories for sounds we’ve learned early in life can still be retrieved, years later.

Finally, the results showed that, even after many years (or even decades) of disuse of their birth language, international adoptees have managed to somehow “keep” some of the knowledge of their birth language. In other words, it seems that remnants of the adoptees’ birth language can be retained until adulthood and can be successfully retrieved after a short training period. Thus, it appears that the knowledge of a birth language does not fall into attrition and eventual oblivion, but is instead preserved and retained, despite its long period of “sleep”. Thus, it seems to be the case, as Singh et al. (2011) stated, that “you do not lose what you do not use”.

Read more

  • Brandeis University, (2011, February 23). Capsule History of International Adoption. Retrieved on 17 November 2020, from:
  • Choi, J., Broersma, M., & Cutler, A. (2017). Early phonology revealed by international adoptees’ birth language retention. Proceedings of the National Academy of Sciences, 114(28), 7307-7312.
  • Park, H. S. (2015). Korean adoptees in Sweden: Have they lost their first language completely?. Applied Psycholinguistics, 36(4), 773.
  • Singh, L., Liederman, J., Mierzejewski, R., & Barnes, J. (2011). Rapid reacquisition of native phoneme contrasts after disuse: You do not always lose what you do not use. Developmental science, 14(5), 949-959.
  • Ventureyra, V. A., Pallier, C., & Yoo, H. Y. (2004). The loss of first language phonetic perception in adopted Koreans. Journal of Neurolinguistics, 17(1), 79-91.
  • Zhou, W. (2015). Assessing birth language memory in young adoptees (Doctoral dissertation, Radboud University Nijmegen Nijmegen).

Writer: Adam Psomakas
Editor: John Huisman
Dutch translation: Dennis Joosen
German translation: Barbara Molz
Final editing: Eva Poort, Merel Wolf