Marianne Nikolov, Professor Emerita, University of Pécs and Shelagh Rixon, Retired Associate Professor, Warwick University
This literature review synthesizes research on the benefits of additional language learning in K–12 education and beyond. It examines how these benefits are framed in educational policy and theory, with particular attention to those supported by empirical research. The study also identifies the conditions necessary for these benefits to emerge and highlights key lessons drawn from the evidence. To conduct the literature review, the researchers examined 620 texts from applied linguistics, psychology and education, ultimately synthesizing 314 sources, including reviews, meta-analyses, empirical studies and educational documentation. While content and language integrated learning (CLIL) is widely promoted, the evidence shows little to no added value for learners’ additional language development or subject knowledge, with observed benefits often attributable to learner selection rather than program design. Most studies support slight cognitive advantages for bilinguals—such as improved executive function, delayed cognitive decline and enhanced language-learning aptitude—though limited detail in many studies makes it difficult to draw definitive conclusions regarding program types or age groups. Based on the research, plurilingual individuals tend to have a clear economic advantage in the job market, with added value ranging from 10% to 20%, although outcomes vary between individuals born in the country and those who immigrated.
