A leading proponent of socio-cultural theory in second language acquisition, James Lantolf graduated from Pennsylvania State University with a PhD in linguistics ins 1974, and since 1980 has been professor of (applied) linguistics at the universities of Delaware, Cornell and now Penn State, where he has directed the Center for Advanced Language Proficiency Education and Research (CALPER) since 2005.
Lantolf co-edited Applied Linguistics from 1993 to 1998, founded the Sociocultural Theory and Second Language Learning research group in 1993, and has published a number of books on SCT and second language teaching and learning.
Lantolf, J. P. (2000). Sociocultural theory and second language learning. Oxford University Press.
Lantolf, J. P. & S. L. Thorne. (2006) Sociocultural theory and the genesis of second language development. Oxford University Press.
Lantolf, J. P. & M. E. Poehner. (2008). Sociocultural theory and the teaching of second languages. London: Equinox Press.