Home Issue 1, Volume 2 • The Bilingual Advantage Dilemma: Psychological Fact or Failure to Replicate?

The Bilingual Advantage Dilemma: Psychological Fact or Failure to Replicate?


Caption: An English/French stop sign in Canada, where bilingualism is both a rite of passage and a multicultural necessity. By bobbsled. (Photographer). (2009, June 22). Panneau Bilingue Stop/Arrêt Bilingual Sign [digital image]. Image retrieved from: https://www.flickr.com/photos/mpd01605/3810679130 (2009), licensed under CC BY 2.0.

Many Canadian families with young children consider early enrollment in French Immersion programs as a way for their children to do better in school, rather than just learning to communicate using a different language. Since speaking two languages fluently (bilingualism) as opposed to only one language (monolingualism) is considered advantageous, parents and guardians are concerned that an English-only public school education may be putting their children at a disadvantage for both future job prospects and test scores. These concerns are primarily rooted in claims made by many French Immersion programs that early bilingualism leads to higher reading levels and general cognitive abilities. Are these claims supported by scientific evidence? Is there a critical age range where learning a second language has the most advantages? At what age does this “bilingual advantage” truly begin and end? Psychologists researching childhood development and cognitive benefits have been investigating questions like this for a long time to try and settle the debate of bilingual advantages.

The debate began in 1988 when Dr. Ellen Bialystok pioneered the bilingual advantage hypothesis which proposed that bilingualism leads to significant cognitive benefits throughout our lives. Across roughly a decade of her published research, Bialystok has pushed the idea that a lifetime of switching between languages depending on the language environment may improve cognitive development. To that end, the bilingual advantage hypothesis suggests that practicing bilingualism in childhood ultimately predicts an improvement in adolescent and adult cognitive skills such as memory, mental flexibility, decision-making, and controlling impulsive reactions.

Despite all of the positive benefits proposed, the bilingual advantage hypothesis has recently come under scrutiny after several studies have failed to replicate Bialystok’s findings.

At Western University, recent publications from the Cognitive Development and Neuroimaging Laboratory (CDNL) have challenged the bilingual advantage hypothesis after attempts to replicate Bialystok revealed vastly different results. The CDNL’s research involves both children and adults and has shown that bilinguals and monolinguals do not significantly differ in their performance on cognitive tasks – in other words, they did not find an advantage of being bilingual.

“The [bilingual advantage] hypothesis is intuitively very appealing – bilinguals have a lot of practice switching between languages, and it makes sense to think that practice might translate into better performance on cognitive tasks,” says Samantha Goldsmith, PhD candidate in Psychology and part of the CDNL group. “However, a large number of replication failures – including our own study – suggests otherwise. The data simply doesn’t show a bilingual advantage.”

In an experiment designed to measure how we learn from prior experience on cognitive tasks, lead author Goldsmith and principal investigator Dr. J. Bruce Morton tested this hypothesis by attempting to replicate findings that demonstrated a significant effect of bilingualism. To do so, they examined the performance of monolingual and bilingual adults on a “flanker task”, where participants have to quickly respond to an aspect of a middle target that is ‘flanked’ by other distractor stimuli in either a ‘low conflict’ or ‘high conflict’ condition. Low conflict conditions are when the properties of all the flanking stimuli match the identity of the target stimulus. For example, if responding to stimulus direction, this set of stimuli would be considered low conflict:  > > > > >. High conflict conditions are when the flanking stimuli are different from the middle target stimulus (e.g., < < > < < ) which makes it more difficult to quickly make a correct response. However, as one encounters more of these high conflict conditions, they become faster and more accurate at responding to them – a process described as ‘cognitive adaptation’.

The bilingual advantage hypothesis posits that bilinguals have long-term practice for selecting between two conflicting representations of a word, for example, “apple” in English versus “pomme” in French. This implies that bilinguals may have experienced more ‘cognitive adaptation’ over time and should be better at selecting the correct response in the high conflict condition on the flanker task compared to monolinguals. If Bialystok’s bilingual advantage hypothesis holds true, then encountering a large amount of ‘high conflict’ scenarios in daily life should theoretically increase performance for bilinguals on the flanker task.

While this theory may sound appealing, the data showed otherwise: Goldsmith and Morton found no differences in performance between bilingual and monolingual adults on the flanker task. How could this be when Bialystok was able to find significantly different results for bilingual children and adults?

“…Some studies do show a very small difference between bilinguals and monolinguals. But this difference vanishes once you control for individual differences in basic variables like age, socioeconomic status, and non-verbal intelligence”, Goldsmith explains.

In response to replication failures with adults, such as this one, proponents of the hypothesis have also suggested the advantage might just be stronger in bilingual children. “But given the argument that the bilingual advantage is the result of ‘a lifetime of practice,’ the effect should actually be diminished in children compared to adults,” argues Goldsmith.

In essence, given that children are younger and have not had as much experience being bilingual, the effects of bilingualism in children would be even less significant than any potential effect of bilingual advantage in adults. With this in mind, any difference in student grades between French Immersion and English-only public-school programs may have less to do with their language status and more to do environmental benefits, like a better curriculum, facilities, or even materials that the school provides.

Considering all of these conflicting hypotheses and results, much of the reason this debate has gone on as long as it has is because this type of academic research provides the basis for educational policies and government sponsored programs. In light of recent provincial budget cuts for education and without a clear advantageous effect of bilingualism, parents and educators are apprehensive that funding for second language programs might decrease drastically. For Canada, where bilingualism is highly sought after as both a skill and as part of preserving the Canadian French-speaking identity, Goldsmith notes that, “…although our studies suggest no cognitive advantage in bilingualism, there are still undoubtedly many social, practical, and communicative benefits to being able to speak multiple languages!”

The bilingual advantage hypothesis has been very helpful in boosting the popularity of bilingualism, even if supporting evidence has dwindled. When taking into account the effect that research has on society as a whole, Bialystok’s work has been monumental in advocating for more children and adults to learn another language. Be that as it may, the pendulum of research must also swing the opposite way when results are not truly representative – in this case, a lack of advantageous difference between monolinguals and bilinguals. Parents interested in enrolling their children into French Immersion should do so because speaking French is incredibly useful for communication; not because they are afraid their children would lose out on cognitive benefits.

Academic research is less about opinion than it is about arguing and pursuing objective truths behind human development. “While the intuitiveness of this hypothesis is often compelling, as responsible researchers we have an obligation to follow the data,” Goldsmith asserts.


Original Research Article:

Goldsmith, S. & Morton, J. B. (2018). Sequential Congruency Effects in Monolingual and Bilingual Adults: A Failure to Replicate Grundy et al. (2017). Frontiers in Psychology, 9, 2476. DOI: 10.3389/fpsyg.2018.02476


Barac, R. & Bialystok, E. (2011). Cognitive development of bilingual children. Language Teaching, 44(1), 36-54. DOI: 10.1017/S0261444810000339

Bialystok, E. (1988). Levels of bilingualism and levels of linguistic awareness. Developmental Psychology, 24(4), 560–567. DOI: 10.1037/0012-1649.24.4.560


Author:::Josephine Pham