Presents state-of-the-art knowledge about languages in contact from individual bilingualism (or bilinguality) to societal bilingualism.

Foreword to the second edition; Preface; Introduction; 1. Definitions and guiding principles; 2. Dimensions and measurement of bilinguality and bilingualism; 3. The ontogenesis of bilinguality; 4. Bilinguality: cognitive development and the sociocultural context; 5. The social and psychological foundations of bilinguality; 6. Bilinguality: neuropsychological foundations; 7. Information processing in the bilingual; 8. Social psychological aspects of bilinguality: culture and identity; 9. Social psychological aspects of bilinguality: intercultural communication; 10. Societal bilingualism, intergroup relations and sociolinguistic variations; 11. Bilingual education; Conclusion; Notes; Glossary; References; Subject index; Author index.