James Lantolf has become identified with the sociocultural approach to second language acquisition, as developed from the original ideas of Russian psychologist Lev Vygotsky (1896-1934) and others. His introductory essays in Lantolf and Appel (1994) and Lantolf (2000) are widely cited essential digests of the basic principles and concepts of this theoretical paradigm. Professor Lantolf is Greer Professor in Language Acquisition and Applied Linguistics; Director of the Center for Language Acquisition; and Co–Director of CALPER (Center for Advanced Language Proficiency Education and Research) at Pennsylvania State University. Dr. Lantolf is also the founder of the Sociocultural Theory and Second Language Learning Research Group, which began to meet in 1993. His dozens of publications include three seminal volumes on sociocultural theory: the two collections of articles mentioned above, and a new book, Sociocultural Theory and the Genesis of Second Language Development (2006, coauthor Steven L. Thorne) published by Oxford University Press.