Human memory isn’t perfect but its also far more plastic than some people give it credit. For instance, a new study found that the earliest traces of a language can stay with us well into adulthood even if today we can no longer understand, let alone speak the language. According to the paper published in the journal Royal Society Open Science, this subconscious knowledge can then be exploited to speed up the language acquisition process.

Credit: Radboud University.

The findings were reported by an international team of Dutch and South Korean researchers who studied 29 Korean-born Dutch speakers and an equal-sized native Dutch-speaking control group. The first group was essentially made of people born in Korea but adopted by Dutch families before the age of six.  With no exception, all participants reported they could not speak a word in Korean.

For two weeks, the adoptees were trained to identify three Korean consonants and asked to reproduce them. These sounds were unlike anything in the Dutch language.

At the end of the training period, the participants’ attempts at Korean utterances were rated by native Koreans. Ultimately, the researchers found that the adoptees improved far more quicker across the training period than the control group.

At an age when babies can barely babble, there’s much more going on than meets the eye

The most striking find, however, was that the rate of learning was just as accelerated even for those adopted before the age of six months. At this age, babies can’t speak but the experiment proves there’s some kind of assimilation that subconsciously stays with us well into adulthood.

“One of the most interesting findings was that no difference showed in the learning results of those Korean-born participants adopted under six months of age and those adopted after the age of seventeen months,” explained Mirjam Broersma, who is a language scientist at Radboud University and the Max Planck Institute for Psycholinguistics (MPI). “This means that even in the very early months of life, useful language knowledge is laid down, and what has been retained about the birth language is abstract knowledge about what patterns are possible, not, for instance, words.”

The first six months of our lives can be very wild and there’s a lot we learn in this short time. It was never clear up to now, however, how much of that learning is retained even if there’s no further input from a language. Whatever the case, for the thousands of people who were adopted internationally this may come as good news, especially for those looking to reconnect with their ancestral roots — the people, culture, and language of their birthplace.

Previously, researchers from McGill University, Canada performed a similar experiment with children from China adopted in France. They found the participants’ brain activity carried the same response as bilinguals even though by all accounts they looked monolingual. Bilinguals get distracted less easily, are better at multitasking,  find creative solutions to problems more often, have increased memory capacity, and lower risk of Alzheimer’s. So, it seems that being exposed to a foreign language very early on can have lasting benefits later in life.