What it means to be bilingual.

Darlene Gomez | June 1, 2021 | CGSC 216: The Cognitive Science of Language, Yale University

In this blog, we will hone in on the direct definition of bilingualism, but also paint a better picture of the bilingual experience by looking at common myths held for those who speak two languages. However, we will not only look at misconceptions, but also multiple historical lenses through which bilingualism has been stigmatized, in both a political and scientific sense, to get a full picture of historical discrimination against bilingual individuals. Then we will see how such past negative connotations are contested by modern advancements in science by exploring the benefits of bilingualism on brain structure and cognitive abilities. After looking at some brain differences, we will venture into how such benefits come to be by examining potential mechanisms through which the acquisition and regulation of two languages impacts your brain’s flexibility. Lastly, because oftentimes bilingualism is tightly intertwined with biculturalism, we will probe the question of whether the language you speak impacts your attitudes, emotions, and decisions — a test of the Sapir-Whorf Hypothesis wherein one’s perception of the world is relative to their spoken language. All of this will help to encompass the bilingual experience and what exactly it means to be bilingual both cognitively and culturally.

What is bilingualism?

At its simplest definition, bilingualism refers to the use of two or more languages or dialects in one’s daily life (Grosjean, 1982). This does not necessarily mean that the speaker must have full knowledge and command of two complex languages but rather uses both regularly. Defining bilingual based on language use as opposed to measures of fluency is a debate that goes as far back as the 1960s. But, this way, the definition encompasses various diverse bilingual experiences “ranging from the migrant worker who speaks the host country’s language, and who may not read and write it, all the way to the professional interpreter who is totally fluent in two languages” (p. 573)(Grosjean, 2015). The image below is just one way of visualizing measures of the diverse bilingual experience, but several other matrices can be involved in trying to map out the bilingual experience like language competencies (speaking, listening, writing, reading), age of acquisition, language history, etc.

Frequency > Fluency: Therefore, being bilingual is less about how fluent you are and more about how much you use the two languages in your daily life.

How else can we better characterize bilingualism?

One way is by addressing multiple myths, I highly recommend viewing this review of what bilingualism is NOT, as well as other common misconceptions.

Foreign Language in a Global world

As the world becomes more and more globalized, learning multiple languages is seen as not only advantageous in personal life for travel, social connections, and media consumption, but also career prospects. However, viewing bilingualism as a valued asset wasn’t always the sentiment in America during the last century. As a minority in the United States, it comes to no surprise that bilingualism is tightly intertwined with immigration politics. Part of the reason why I chose this topic was to delve into the progressive neuroscience behind something that was once deemed highly unfavorable.

Brief History: Immigrant assimilation, language politics, and the stigma of bilingualism

At its conception the United States has been touted as a country of immigrants; however, soon after the end of the initial influx of immigrants, European immigrants quickly abandoned their ethnic customs and sought to assimilate in what they believed was required to succeed in America. This is a sentiment that is still held to this day, as seen in this Toyota commercial. Speaking English was a prominent part of the Anglo American model, so much so that speaking foreign languages was seen as un-American and unpatriotic. Past president Theodore Roosevelt even stated, “we have room for but one language here, and that language is English, for we intend to see that the crucible turns our people out as Americans and not as dwellers in a polyglot boarding house” (Linton, 2002). By contrast, with new waves of immigration facilitated by cross-border labor markets of the 1930s, instead of contributing to the “melting pot,” Mexican immigrants effectively maintained their Spanish because they were segregated and discouraged from membership in American society. But, during the Civil Rights Era, Congress passed the Bilingual Education Act of 1968 meant to assist limited English-speaking immigrant children in school; it instead, however, “further associated bilingualism with disadvantage, cultural deprivation, and alienation… and perpetuated the norm of subtractive bilingualism” (p. 11) or the act of learning a second language at the expense of one’s first language and ultimately losing command of one’s native tongue (Linton, 2002). Altogether, like many other bilingual programs, its primary purpose was never maintenance of native language but rather transition to English under the guise of equal education opportunity via English proficiency as a compensatory program for immigrants (Linton, 2002). Programs like English for the Children viewed foreign language as a problem that must be overcome. All in all, throughout the history of America, the sentiment can be summarized as follows:

“for many people bilingual is a euphemism for ‘linguistically handicapped.’ A nice way of referring to children whose parents have handicapped them in the race for success by teaching them their mother tongue (p. 308)” — Linguist Einar Haugen (1972) “The Stigma of Bilingualism”

These discriminatory attitudes were further reflected in the scientific literature. Like Francis Galton, the father of eugenics, psychologists of the 19th century searched for scientific measures for human intelligence. Amongst them was Henry H. Goddard, a prominent American psychologist, eugenicist, and segregationist who pioneered the use of intelligence tests at Ellis Island to limit the entry of newly arrived immigrants. This led to a rapid surge in the psychological literature with tales of non-English speaking immigrants having lower intelligence because of their performance on English-based exams. Following suit, further studies of the early 20th century concluded that bilingualism hindered children’s cognitive development because of decreased vocabulary, ‘psychodynamic conflicts’, and worse performance on a variety of measures of language (Hakuta, 1986).

To this day, bilingual education remains a pressing issue dividing the American people, but bilingualism itself is held in a much more positive light than before thanks to novel advancements in research. There is now evidence that speaking multiple languages actually has a multitude of benefits like improving brain function and executive control, increasing mental flexibility, and protecting against cognitive aging.

Cognitive Benefits of Bilingualism

The first of these breakthrough studies was by Peal and Lambert (1962) who found that bilingual children were superior on a multitude of both verbal and non-verbal tests as compared to monolingual children. These tests demonstrated “mental flexibility, a superiority in concept formation, and a more diversified set of mental abilities” in bilingual children (p.22) (Peal & Lambert, 1962). Further research corroborates the argument for improved concept formation demonstrating that bilingual children reach greater maturity in semantic development approximately 2–3 years earlier than their monolingual peers. The study found that bilingual children were more apt to perceiving relationship of words in terms of their symbolic rather than their acoustic properties, otherwise known as improved meta-linguistic awareness (Ianco-Worrall, 1972). Beyond this, bilingualism is also argued to improve executive attention, allowing children to ignore misleading information during problem solving (Bialystok & Majumder, 1998).

Case Study: Attentional benefits of Bilingualism

The effects of improved executive attention are often found using conflict tasks like the flanker task and Stroop task where subjects are required to ignore misleading information in order to produce an accurate response. The flanker task asks participants to tell the direction of a target arrow that is in the middle of nearby arrows that are either in the same direction of (congruent) or in the opposite direction (incongruent) of the target arrow, exemplified in the image below (Fig 2). Bilingual children were found to accurately respond at a higher and faster rate in both conditions (Costa, Hernández, & Sebastián-Gallés, 2008; Yang, Yang, & Lust, 2011). Similarly, in the Stroop task which requires reading the names of colors in conflicting font colors, pictured below (Fig. 3), bilinguals demonstrate significantly better performance (Bialystok, Craik, & Luk, 2008). This effect was also seen in a nonlinguistic numerical version of the Stroop task which required participants to respond with the amount of digits presented when the digits presented either matched the value of the amount (congruent) (ex: 1, 22, 333) or did not (incongruent) (ex. 111, 2, 33) (M. Hernandez, Costa, Fuentes, Vivas, & Sebastian-Galles, 2010).

Altogether, a meta-analysis of 63 studies comprising over six thousand participants, illustrated that acquiring and simultaneously managing two languages, gives “bilingual speakers an enhanced capacity to appropriately control and distribute their attentional resources, to develop abstract and symbolic representations, and to solve problems” (p. 229)(Adesope, Lavin, Thompson, & Ungerleider, 2010).

Reaping the Benefits: Mechanism of Action. Why do bilinguals have attentional benefits?

As hinted above, the reason why bilinguals outperform monolinguals on some cognitive tests is theorized to come from developing and strengthening skills that require directing attention and resolving competition which ultimately affects cognitive capacity outside of language use. Early on, this was speculated as a specialized facility for seeking out patterns of rules required for determining circumstances (Ben-Zeev, 1977). Moreover, because bilingual language use requires you to appropriately use a specific language without interference of a second language within a specific context, the bilingual advantage allows for efficient conflict resolution (Bialystok, Craik, & Luk, 2012) with reduced interference (M. Hernandez et al., 2010) and improved goal selection and maintenance (Colzato et al., 2008).

Bilingualism as a Cognitive Reserve against Aging

Clearly, being bilingual has cognitive benefits, however its potential impact on lifespan cognition is much more significant. Research has shown that bilingual cognitive advantages extend into older age (Bialystok, Craik, Klein, & Viswanathan, 2004) and may have long-term effects in preventing disease. A 2014 study found that bilinguals had significantly improved cognitive abilities, most notably in general intelligence and reading, over time as compared to their original tests at age 11 in 1947 (Bak, Nissan, Allerhand, & Deary, 2014). Additionally, with age, comes brain atrophy, and, eventually, cognitive atrophy like dementia or Alzheimer’s disease (AD). However, interestingly, research has found that being bilingual can delay the onset of AD (Craik, Bialystok, & Freedman, 2010), such that much greater neuropathology is required to manifest AD in bilingual patients. Therefore, despite brain aging, bilinguals maintain longer healthy functioning without AD symptoms (Schweizer, Ware, Fischer, Craik, & Bialystok, 2012). Similar effects are seen in dementia as well, delaying symptoms by 4 years in bilinguals (Bialystok, Craik, & Freedman, 2007). Furthermore, the mental stimulation and engagement required by bilingualism may act to preserve cognitive functioning in healthy aging, functionally acting as what is known as a cognitive reserve.

The Bilingual Brain

Altogether, seeing the impact of bilingualism on cognition, it comes to no surprise that we can see this reflected in the brain’s structure as well. For one, directing attention and resolving conflict are specifically executive functions and the dorsolateral prefrontal cortex, a significant player in executive control, has been shown to specifically activate in bilingual language switching — noted as the “language switch” (A. E. Hernandez, Martinez, & Kohnert, 2000). In fact, even in non-linguistic cognitive control tasks, bilinguals activate networks that underlie language control because of their frequent connection to cognitive control via language switching (Garbin et al., 2010). A later meta-analysis study corroborated this connection demonstrating further activation of left prefrontal regions in bilingual language control (G. Luk, Green, Abutalebi, & Grady, 2011). However, other parts of the brain are implicated in bilingualism as well, creating marked brain differences in bilingual brains. Notably, bilinguals show higher grey matter density (Mechelli et al., 2004), distinct white matter tracts (Mohades et al., 2012), and greater white matter integrity (G Luk, Bialystok, Craik, & Grady, 2011).

The Bilingual Person

For any baby learning language, it is imperative to be able to discriminate specific properties of their language in order to properly engage with it; but once they’ve learned all that they need to navigate their own language environment, they lose the ability to further discriminate perceptual sensitivities of language irrelevant to theirs. However, interestingly, it has been found that bilingual infants advantageously maintain visual language speech discrimination abilities needed to separate and learn multiple languages (Weikum et al., 2007). That is, bilingual infants as young as 8 months old can tell when someone switches languages just by looking at them talk absent of any sound! So, if being bilingual can impact a baby’s perception of language properties around them, can it also impact their perception of the world around them? This is what is known as linguistic relativity or the Sapir-Whorf hypothesis.

One instance of this is demonstrated in a 2008 study by Luna et al. which found that bilingual women perceived women in advertisements differently based on the language that they were being asked to interpret and respond in. When the study was done in English, participants perceived the women as more submissive and family-oriented whereas in Spanish, they were perceived as more ambitious and independent (Luna, Ringberg, & Peracchio, 2008). So, can our language really change our perception of the world?

Maybe the fact that different languages dedicate words to specific experiences that other languages don’t, proves that we experience the world differently based on our language. This is exemplified in Untranslatable words, a project by Pei-Ying Lin wherein language is thought to impact how someone experiences emotion. Her graphic (Fig. 4) demonstrates multiple words in other languages used to express emotion that cannot be directly translated into English. Similarly, another study found that your decisions are dependent on the language that you employ. Specifically, using a foreign language instead of your native tongue reduces biases and promotes analytic and systematic reasoning which directly impacts decision making (Keysar, Hayakawa, & An, 2012). So, are we really different people based on our language? Does language change how we perceive the world?

Without a deep dive into this, biculturalism makes it clear that this isn’t necessarily the case. Bilingualism is oftentimes tied to biculturalism. Ervin (1964) argues that over time the use of a language can become associated with a shift in behavior simply because the acquisition of each language is accompanied by and used for different contexts, people, and purposes. This is what Grosjean (2015) refers to as the Complementarity Principle.

So, it’s not that our language impacts our perception or personality per se, but rather the use of a different language suggests a context shift, thereby shifting attitudes and behaviors accordingly (Grosjean, 2015). This idea isn’t new; people of color and, specifically, African Americans in the U.S. have been using code-switching to navigate white spaces for years. This article and this video detail the experience of code switching as a Black person with implications in career, law, and even death. Furthermore, the bilingual experience is entangled with biculturalism, such that alongside code-switching are cultural switches leading us to express ourselves differently.

This is bilingualism.

In conclusion, this blog was meant to encompass the bilingual experience to detail what it truly means to be bilingual, outside of simply knowing and using two languages. It doesn’t just mean that our brains work faster and better to process and execute control, but we altogether navigate the world differently because bilingualism offers linguistic, racial, and cultural diversity. The diverse life experiences that we gain from speaking multiple languages creates stimulation, plasticity, and cognitive benefits in our brains that have positive long-term effects. But, these diverse life experiences also come from navigating monolingual spaces, where bilingualism has historically been incorrectly viewed as a detriment to one’s intelligence. Furthermore, bilingualism and the diverse life experiences it welcomes, altogether, shape who we are both culturally and cognitively.


Adesope, O. O., Lavin, T., Thompson, T., & Ungerleider, C. (2010). A Systematic Review and Meta-Analysis of the Cognitive Correlates of Bilingualism. Review of Educational Research, 80(2), 207–245. doi:10.3102/0034654310368803

Bak, T. H., Nissan, J. J., Allerhand, M. M., & Deary, I. J. (2014). Does bilingualism influence cognitive aging? Annals of neurology, 75(6), 959–963. doi:10.1002/ana.24158

Ben-Zeev, S. (1977). The Influence of Bilingualism on Cognitive Strategy and Cognitive Development. Child Development, 48(3), 1009–1018.

Bialystok, E., Craik, F., & Luk, G. (2008). Cognitive Control and Lexical Access in Younger and Older Bilinguals. Journal of Experimental Psychology: Learning, Memory, and Cognition, 34(4), 859–873. doi:10.1037/0278–7393.34.4.859

Bialystok, E., Craik, F. I. M., & Freedman, M. (2007). Bilingualism as a protection against the onset of symptoms of dementia. Neuropsychologia, 45(2), 459–464. doi:10.1016/j.neuropsychologia.2006.10.009

Bialystok, E., Craik, F. I. M., Klein, R., & Viswanathan, M. (2004). Bilingualism, Aging, and Cognitive Control: Evidence From the Simon Task. Psychology and Aging, 19(2), 290–303. doi:10.1037/0882–7974.19.2.290

Bialystok, E., Craik, F. I. M., & Luk, G. (2012). Bilingualism: Consequences for Mind and Brain. Trends Cogn Sci, 16(4), 240–250. doi:10.1016/j.tics.2012.03.001

Bialystok, E., & Majumder, S. (1998). The relationship between bilingualism and the development of cognitive processes in problem-solving. Appl. Psycholinguist, 19, 69–85.

Colzato, L. S., Bajo, M. T., Wildenberg, W., Paolieri, D., Nieuwenhuis, S., Heij, W. L., & Hommel, B. (2008). How does bilingualism improve executive control? A comparison of active and reactive inhibition mechanisms. J Exp Psychol Learn Mem Cogn, 34(2), 302–312. doi:10.1037/0278–7393.34.2.302

Costa, A., Hernández, M., & Sebastián-Gallés, N. (2008). Bilingualism aids conflict resolution: Evidence from the ANT task. Cognition, 106(1), 59–86. doi:10.1016/j.cognition.2006.12.013

Craik, F. I., Bialystok, E., & Freedman, M. (2010). Delaying the onset of Alzheimer disease: bilingualism as a form of cognitive reserve. Neurology, 75 (19), 1726–1729. doi:10.1212/WNL.0b013e3181fc2a1c

Ervin, S. (1964). Language and TAT content in bilinguals. Journal of Abnormal and Social Psychology, 68, 500–507.

Garbin, G., Sanjuan, A., Forn, C., Bustamante, J. C., Rodriguez-Pujadas, A., Belloch, V., . . . Ávila, C. (2010). Bridging language and attention: Brain basis of the impact of bilingualism on cognitive control. NeuroImage, 53(4), 1272–1278. doi:10.1016/j.neuroimage.2010.05.078

Grosjean, F. o. (1982). Life with two languages: An introduction to bilingualism. Cambridge, MA: Harvard University Press.

Grosjean, F. o. (2015). Bicultural bilinguals. International Journal of Bilingualism, 19(5), 572–586. doi:10.1177/1367006914526297

Hakuta, K. (1986). Bilingualism and Intelligence. In Mirror of Language: The Debate on Bilingualism (pp. 14–44). New York: Basic Books, Inc., Publishers.

Haugen, E. (1972). The Stigma of Bilingualism. In The Ecology of Language: Essays by Einar Haugen (pp. 307–324). Stanford, CA: Stanford University Press.

Hernandez, A. E., Martinez, A., & Kohnert, K. (2000). In Search of the Language Switch: An fMRI Study of Picture Naming in Spanish-English Bilinguals. Brain and Language, 73, 421–431. doi:10.1006/brln.1999.2278

Hernandez, M., Costa, A., Fuentes, L. J., Vivas, A. B., & Sebastian-Galles, N. ( 2010). The impact of bilingualism on the executive control and orienting networks of attention. Bilingualism: Language and Cognition, 13(3), 315–325. doi:10.1017/S1366728909990010

Ianco-Worrall, A. D. (1972). Bilingualism and Cognitive Development. Child Development, 43(4), 1390–1400.

Keysar, B., Hayakawa, S. L., & An, S. G. (2012). The Foreign-Language Effect: Thinking in a Foreign Tongue Reduces Decision Biases. Psychological Science, 23(6), 661–668. doi:10.1177/0956797611432178

Lin, P.-Y. (2012). Untranslatable Words in Languages other than English, v.s. Parrott’s Classification In Other_Languages_b.png (Ed.), Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License.

Linton, A. (2002). Spanish for Americans? The Politics of Biligualism in the United States. [Doctoral Dissertation, University of Washington](Access №3062978), ProQuest Information and Learning Company.

Luk, G., Bialystok, E., Craik, F., & Grady, C. (2011). Lifelong bilingualism maintains white matter integrity in older adults. J Neurosci, 31(46), 16808–16813. doi:10.1523/JNEUROSCI.4563–11.2011

Luk, G., Green, D. W., Abutalebi, J., & Grady, C. (2011). Cognitive control for language switching in bilinguals: A quantitative meta-analysis of functional neuroimaging studies. Language and cognitive processes, 27(10), 1479–1488. doi:10.1080/01690965.2011.613209

Luna, D., Ringberg, T., & Peracchio, L. (2008). One individual, two identities: Frame switching among biculturals. Journal of Consumer Research, 35, 279–293.

Mechelli, A., Crinion, J. T., Noppeney, U., O’Doherty, J., Ashburner, J., Frackowiak, R. S., & Price, C. J. (2004). Structural plasticity in the bilingual brain. Nature, 431, 757. doi:10.1038/431757a

Mohades, S., Struys, E., Van Schuerbeek, P., Mondt, K., Van De Craen, P., & Luypaert, R. (2012). DTI reveals structural differences in white matter tracts between bilingual and monolingual children. . Brain Res., 1435, 72–80. doi:10.1016/j.brainres.2011.12.005.

Peal, E., & Lambert, W. E. (1962). The Relation Of Bilingualism To Intelligence. Psychological Monographs: General and Applied, 76(27), 1–23. doi:10.1037/h0093840

Schweizer, T. A., Ware, J., Fischer, C. E., Craik, F. I. M., & Bialystok, E. (2012). Bilingualism as a contributor to cognitive reserve: Evidence from brain atrophy in Alzheimer’s disease. Cortex, 48(8), 991–996. doi:10.1016/j.cortex.2011.04.009

Weikum, W. M., Vouloumanos, A., Navarra, J., Soto-Faraco, S., Sebastián-Gallés, N. r., & Werker, J. F. (2007). Visual Language Discrimination in Infancy. Science, 316, 5828. doi:10.1126/science.1137686

Yang, S., Yang, H., & Lust, B. (2011). Early childhood bilingualism leads to advances in executive attention: Dissociating culture and language. Bilingualism: Language and Cognition, 14(3), 412–422. doi:10.1017/S1366728910000611

Los Angeles, Yale 2021