Does language diversity affect multilingual cognition?

While some investigators have found that multilingualism in adults is associated with better cognition compared to monolingual adults (Bialystok, 2021), others have found no differences (Paap et al., 2020). Most studies on multilingualism and cognitive aging treat multilingual adults as a single group when they demonstrate substantial within-group variability.

A key factor on which multilingual speakers differ is whether they know languages from the same language family or from different language families. Prior studies have combined different language pairs within a multilingual group regardless of the linguistic similarity between the languages (Ballarini et al., 2023; von Bastian et al., 2016). The demands of cross-language interference may potentially strengthen cognitive control among multilingual speakers, suggesting that more similar languages may be more prone to interference and thus provide more frequent opportunities to strengthen cognitive control (Oschwald et al., 2018). Thus, the current study from Petrosyan et al. (2025) published in Neuropsychology examined how these linguistic differences relate to cognitive function in older multilingual adults in India.  

India has more than 120 languages, including 22 scheduled officially recognized languages, as well as 99 nonscheduled languages (Census of India, 2011). In addition, this variety spans across 5 Indian language families and several non-Indian language families. Given this rich linguistic diversity across all socioeconomic gradients, India provides the perfect opportunity to evaluate the relationship of multilingualism with cognition.

Petrosyan et al. used data from the Longitudinal Aging Study in India–Diagnostic Assessment of Dementia (LASI­–DAD; Lee et al., 2019), a nationally representative sample of 4,088 Indian adults ages 60 or older, speaking 40 languages and dialects (54% without formal schooling). Participants were categorized based on whether they spoke 2 or more languages within the same or different language families. Participants completed a comprehensive cognitive battery assessing memory, language, executive functioning, and visuospatial ability.

Regression models evaluated the association of language status (multilingual similar, multilingual different, and monolingual) on each cognitive factor score stratified by education (with and without education) and adjusted for relevant covariates. Given that group differences in the distribution of covariates may be nontrivial and systematic (e.g., greater proportion of women and individuals with lower educational attainment among monolingual speakers) and simply adjusting for them in analyses might lead to spurious results (Miller & Chapman, 2001), the researchers also ran their analyses among a propensity-score matched sample to ensure adequate covariate balance.

After adjusting for covariates in the full and matched samples, multilingual participants with formal education outperformed monolingual participants across cognitive domains, regardless of language similarity. However, among those without formal schooling, only multilingual participants speaking related languages showed a cognitive advantage. Findings demonstrate potential for examining the relationship between multilingualism and cognition in large population-based cohort studies. Future measurement of multilingualism’s various attributes, such as language proficiency and frequency of use, will help researchers further explore how managing linguistic interference and exposure to similar languages can enhance late-life cognition.

This article is in the Neuroscience and Cognition topic area.

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Bialystok, E. (2021). Cognitive effects of bilingualism: An evolving perspective. In W. S. Francis (Ed.), Bilingualism across the lifespan: Opportunities and challenges for cognitive research in a global society. Routledge. https://doi.org/10.4324/9781315143996-3opens in new window

Census of India. (2011). Language: India, States and Union Territories, 2011. Office of the Registrar General, India. https://censusindia.gov.in/nada/index.php/catalog/42458/download/46089/C-16_25062018.pdfopens in new window

Lee, J., Banerjee, J., Khobragade, P. Y., Angrisani, M., & Dey, A. B. (2019). LASI–DAD study: A protocol for a prospective cohort study of late-life cognition and dementia in India. BMJ Open, 9(7), Article e030300. https://doi.org/10.1136/bmjopen-2019-030300opens in new window

Miller, G. A., & Chapman, J. P. (2001). Misunderstanding analysis of covariance. Journal of Abnormal Psychology, 110(1), 40–48. https://doi.org/10.1037/0021-843X.110.1.40

Paap, K. R., Mason, L., Zimiga, B., Ayala-Silva, Y., & Frost, M. (2020). The alchemy of confirmation bias transmutes expectations into bilingual advantages: A tale of two new meta-analyses. Quarterly Journal of Experimental Psychology, 73(8), 1290–1299. https://doi.org/10.1177/1747021819900098opens in new window

Petrosyan, S., Strangmann, I. M., Nichols, E., Meijer, E., Briceño, E. M., Narayanan, S., Lee, J., & Arce Rentería, M. (2025). The association of multilingualism with diverse language families and cognition among adults with and without education in India. Neuropsychology, 39(3), 223–234. https://doi.org/10.1037/neu0000988

Oschwald, J., Schättin, A., von Bastian, C. C., & Souza, A. S. (2018). Bidialectalism and bilingualism: Exploring the role of language similarity as a link between linguistic ability and executive control. Frontiers in Psychology, 9, Article 1997. https://doi.org/10.3389/fpsyg.2018.01997opens in new window

von Bastian, C. C., Souza, A. S., & Gade, M. (2016). No evidence for bilingual cognitive advantages: A test of four hypotheses. Journal of Experimental Psychology: General, 145(2), 246–258. https://doi.org/10.1037/xge0000120

Sarah Petrosyan, MPH, is a public health professional with a background in global health research and epidemiology. Her work focuses on the implementation of population-based studies and clinical research strategies, with experience managing large-scale international studies on aging and dementia. She specializes in research project management, data harmonization, and multidisciplinary collaboration to advance global health and cognitive aging research.

Iris Strangmann, PhD, is a postdoctoral research scientist in the laboratory of Miguel Arce Rentería, PhD, at the Columbia University Medical Center. Her research examines how bilingual experience and sociodemographic factors influence the neurocognitive and neurobiological processes underlying aging and Alzheimer’s disease across heterogeneous populations.

Emma Nichols, MPH, PhD, is a research scientist at the University of Southern California Dornsife Center for Economic and Social Research. Her research focuses on cognitive aging and dementia, as well as methodological problems common in epidemiological studies of older adults.

Erik Meijer, PhD, is an econometrician and psychometrician who studies globally the confluence of cognition, physical health, and economic status among middle-aged and older individuals. Recent work includes the measurement of cognition and dementia in nationally representative surveys, along with their determinants and consequences.

Emily M. Briceño, PhD, is a clinical associate professor in the Department of Physical Medicine and Rehabilitation at the University of Michigan Medical School. Her research focuses on neuropsychological assessment for the detection of Alzheimer’s disease and related dementias (ADRD) across culturally, linguistically, and socially varied populations.

Shrikanth (Shri) Narayanan, PhD, is professor and Niki and C. L. Max Nikias Chair in Engineering at the University of Southern California. His interdisciplinary research focuses on human-centered sensing and imaging; signal processing; and machine intelligence centered on human communication, interaction, emotions, and behavior. He is a fellow of the Institute of Electrical and Electronics Engineers, the American Association for the Advancement of Science, the Association for Psychological Science, and the American Institute for Medical and Biological Engineering, among others. He is a recipient of many awards for research and education.

Jinkook Lee, PhD, is a research professor of economics and director of the Global Aging, Health, and Policy Program at the Center for Economic and Social Research, University of Southern California. Her research focuses on the economics of aging. She leads the Gateway Exposome Coordinating Center, which promotes the interdisciplinary study of how environmental exposures over one’s life span can influence cognitive health. Her pioneering work in ADRD research includes developing the LASI–DAD. She also provides scientific advice for several international organizations and serves on the editorial boards of several scientific journals.

Miguel Arce Rentería, PhD, is an assistant professor of neuropsychology at the Taub Institute for Research on Alzheimer’s Disease and the Aging Brain and the Department of Neurology at the Columbia University Medical Center. His research focuses on determining factors of reserve and resilience to cognitive aging and ADRD among racial and ethnic minorities within the United States and abroad, with an emphasis on understanding the role of bilingualism. Contact Miguel Arce Rentería. 

Check out an episode of the Meet the Authors Podcastopens in new window from APA Division 40: Society for Clinical Neuropsychology, featuring senior author Miguel Arce Rentería.