The perks of growing up bilingually
Second-year Psychology students participating in the University Honours College follow a mini-course on Blogging Science (within the Thematic Meetings course), in which they learn to communicate science to the general public, by means of informing, giving an opinion, and relating issues in science to issues in society. This year a selection of these written blog posts is published on Mindwise. Today’s post is by Michelle Braun.
Bilingualism in the earlier days
As surprisingly as it may sound, the number of individuals fluent in two or more languages already surpasses the number of monolingual speakers . Speaking multiple languages seems favorable and especially being raised with two languages simultaneously is portrayed advantageous in popular media (in which it is called the “bilingual advantage”). However, not a long time ago, the reverse opinion was prevailing and my cousin’s parents were advised not to raise him bilingually. This opinion probably emerged in the beginning of the twentieth century where it was believed that bilingualism would decrease children’s intellect and verbal development. Still 30 years ago, scientific findings demonstrated that learning a word in one language could slow the retrieval of the word in another language . Furthermore, in a study by Magiste , response time was slower for bilingual speakers than for monolinguals, as well as the speed for deciding if a presented word really exists or not . Taking together, early research contributed to the former opinion that raising one’s child bilingual (or multilingual) would be detrimental and should be avoided. In contrast to my aunt and uncle, my parents decided to ignore the well-intentioned advices and raised my brother and me to speak Russian and German simultaneously.
After several years of these disappointing studies a switch took place and more recent research points to the positive side of bilingualism. This change can presumably be attributed to the emergence of new technologies like EEG and fMRI. Hence, now even physiological differences between the population of bilingual and monolingual speakers can be measured. For example, recently it was shown that subcortical structures of bilingual individuals are significantly expanded compared to individuals speaking one language . This brain network monitors verbal processes and is developed to a greater extent in bilinguals. A larger subcortical structure is linked to better executive functioning (EF) which is often cited as the reason for the multiple advantages seen in bilingual speakers. EF is a set of mental skills important for attention, memory, and planning. For example, an enhanced EF (seen in bilinguals) is related to better listening skills . The brain of bilinguals have to work harder to distinguish between different types of sound, thereby constantly strengthening the EF and ultimately leading people to focus better while listening. In daily life, being better at listening can lead to further benefits; I could imagine that children pay better attention at school and ultimately are more successful academically. However, according to Karlsson et al. , no differences in intelligence were found between bilingual and monolingual children.
Cognitive flexibility, a cognitive reserve, and Alzheimer’s disease
Nonetheless, bilingualism was linked to improved multitasking skills . Bilingual individuals were found to be able to switch their attention faster from one task to another. In general, they showed increased cognitive flexibility and easier adaptation to unexpected circumstances. This could be explained by the fact that both languages are activated constantly, making bilingual individuals better at managing their attention to the target language while avoiding inference from a non-target language. Thus, when coming into a new situation or in a situation with an overload of stimulus, bilingual individuals seem better at ignoring unnecessary information while focusing on their target. Lastly, and may be most strikingly, bilingualism was connected to a delay in the onset of Alzheimer’s disease by approximately five years . Presumably, bilingualism contributes to a cognitive reserve, which compensates for the accumulation of toxic proteins, the so called amyloid plaques. As neural connections in bilinguals are strengthened to a greater extent, they can act as a compensatory system against the buildup of these toxins. However, the study was only carried out with people susceptible to Alzheimer’s, thus remaining unclear if this advantage could also apply to the general population. Nevertheless, several other studies found similar effects .
The limits of my language are the limits of my world (Ludwig Wittgenstein)
Taking all the modern studies together, can I now infer that I am better at listening, multitasking and that I will probably get Alzheimer five years later than my cousin? Well, most likely not; as for many studies the findings just show what pertains to the whole population of bilinguals and not to individuals in particular. Still, the current standpoint about bilingualism is foremost positive and even though one cannot predict that these benefits will be seen in one’s own child, teaching children multiple languages should be something to aim for. Not in the least because it gives us the opportunity to communicate with many others’. As Ludwig Wittgenstein wrote already in 1922 “the limits of my language are the limits of my world.” .
Relevant links and publications
 Altenberg, E. P., & Cairns, H. S. (1983). The effects of phonotactic constraints on lexical processing in bilingual and monolingual studies. Journal Of Verbal Learning & Verbal Behavior, 22(2), 174-188.
 Burgaleta, M., Sanjuán, A., Ventura-Campos, N., Sebastian-Galles, N., & Ávila, C. (2016). Bilingualism at the core of the brain. Structural differences between bilinguals and monolinguals revealed by subcortical shape analysis. Neuroimage, 125, 437-445.
 Krizman, J., Marian, V., Shook, A., Skoe, E., & Kraus, N. (2012). Subcortical encoding of sound is enhanced in bilinguals and relates to executive function advantages. PNAS Proceedings Of The National Academy Of Sciences Of The United States Of America, 109(20), 7877-7881.
 Karlsson, L. C., Soveri, A., Räsänen, P., Kärnä, A., Delatte, S., Lagerström, E., & … Laine, M. (2015). Bilingualism and performance on two widely used developmental neuropsychological test batteries. Plos ONE, 10(4).
 Alladi, S., Bak, T. H., Duggirala, V., Surampudi, B., Shailaja, M., Shukla, A. K., & … Kaul, S. (2013). Bilingualism delays age at onset of dementia, independent of education and immigration status. Neurology, 81(22), 1938-1944.