What bilingual babies have taught me about life, the universe, and everything

About the talk

Infants acquire language rapidly, and those raised with two or more languages face an additional set of challenges from the outset. They must detect that their input contains more than one language, distinguish and track those languages, and acquire the sounds, words, and structures of each. They do so in social environments where speakers may use one language or several, and may switch between them within a single utterance.

This talk reviews what my lab has learned about these problems over sixteen years at Concordia: how infants begin separating their languages from birth, how they construct vocabularies across two languages, and how they interpret the language mixing common in bilingual homes. I will also reflect on how the work itself changed, as the students and collaborators I have worked with reshaped my questions and methods, and drew me toward open science and large-scale team collaboration. Raising two bilingual children over the same period supplied its own data. The talk is partly a summary of findings and partly an account of what studying bilingual infants has taught me about doing good science, and enjoying it along the way.

About the speaker

Dr. Krista Byers-Heinlein is a professor of Psychology at Concordia University, where she holds the Concordia University Research Chair in Bilingualism and Open Science and directs the Concordia Infant Research Lab. Her research focuses on infants and children who grow up in bilingual environments.

Most notably, she has made discoveries about how very young bilinguals discriminate and differentiate their two languages, and how children are able to learn words in two languages. Her research is supported by numerous grants including from Canadian and American funding agencies.

Dr. Byers-Heinlein has authored more than 90 peer-reviewed articles on early bilingualism in journals such as Psychological Science and Child Development, and published a book entitled The Listening Bilingual: Speech Perception, Comprehension, and Bilingualism. She is a Member of the Royal Society of Canada College of New Scholars, Artists and Scientists, and in 2025 won the Prix Étoile montante for leadership and scientific excellence from the Fonds de Recherche de Québec. Her research is often featured in print and broadcast media, including Psychology Today, PBS, the The Globe and Mail, and the The New York Times.