This book examines the phenomenon of multilingualism in West Africa from a historical, social, and environmental perspective. Chapter 1 explains why the catalogue of African languages established by linguists is not reliable for assessing the linguistic diversity of the region. It also discusses studies that show that the linguistic behavior in multilingual countries is governed by social rules. Chapters 2 and 3 address vertical and horizontal multilingualism in West Africa, considering situations in which several languages occupy the same physical space while forming part of one stratified social organization, and other situations in which small autonomous societies live side by side with little contact. Chapter 4 discusses how the conquest and colonization of West Africa by Europeans arrested the development of socially and linguistically homogeneous societies. Chapter 5 presents an analysis of the resulting sociolinguistic situation in contemporary West African countries. Chapter 6 discusses the impact of linguistic diversity on internal conflict in West African nations, while chapter 7 focuses on the two basic options available to multilingual nation, assimilation or pluralism. Chapter 8 examines the language policies of African leaders, the majority of whom have decided to maintain the ex-colonial language as the official language. (Contains 129 references.) (MDM)