This volume represents a serious attempt to address the many thorny theoretical issues in the field of language development, particularly questions of autonomy versus interaction in mechanisms of language development. The book is organized in sections by age, rather than by language components, in order to address the interaction between different components of language. However, the contributions still retain a variety of theoretical viewpoints.

The book is divided into four parts. Part I, which deals with Foundations and Theoretical Approaches, starts with a chapter by Shafer and Garrido-Nag on the Neurodevelopmental Bases of Language. The chapter is generally well explained, and concentrates mainly on ERP evidence. This is followed by a chapter by Goodluck on generative approaches to language development, which discusses features of child grammars and, not surprisingly, dismisses the possibility that children do not possess their own grammars. This chapter is also clear and accessible, but I felt it could have at least considered alternative (e.g. frequency-based) accounts, even if only in order to dismiss them. Chapter 4 deals with domain-general mechanisms and demonstrates how the same mechanism in two different domains can lead to different outcomes, looking at evidence from speech perception and from word segmentation and meaning. In this chapter, Saffran and Thiessen argue that a domain-general mechanism can still be an innate mechanism. Chapter 5, by Baldwin and Meyer, moves onto social aspects of language development, dealing with the social structuring of word learning, contrasting the understanding of intentionality with statistical regularities that children may be able to discover in others' behaviour, as well as examining the ‘no negative evidence’ argument against behavioural and social explanations of grammatical development. Chapters 6 and 7 deal with the role of input and with Dynamic Systems Theory (DST). In Chapter 6, Gathercole and Hoff present evidence that suggests that input is adequate for language acquisition, including evidence from child-directed speech, and some evidence of adult correction of grammatical errors. Chapter 7 is slightly less transparent, possibly because of the subject matter. In this chapter, Evans addresses interesting issues in, for example, word learning, and contrasts the DST approach with the more familiar mind-as-digital computer model of cognitive science.

Part II deals with Infancy, starting with Chapter 8 by Polka, Rvachew and Mattock, on speech perception and production. This chapter reviews classic and recent work on the processing of native and non-native contrasts, the links between exposure and production, and the interaction between perception and production. Chapter 9, by Gerken, discusses linguistic structure, again in a statistical learning framework; it suggests that this framework may explain a variety of data but that infants need a multiplicity of cues to benefit from their input. This is followed by Chapter 10, in which Poulin-Dubois and Graham examine cognitive processes in word learning, including issues such as the early noun bias in word learning, and object knowledge and categorisation. Part II concludes with a chapter by Naigles and Swensen on syntactic bootstrapping, which is discussed as a multiple trial phenomenon, better in older children, and highly probabilistic. This chapter may have been more appropriately included in Part III.

Part III moves on to early childhood. It covers similar topics to Part II, but largely avoids repetition, with the exception of Chapter 12, where Stoel-Gammon and Sosa deal with phonological development in a similar manner to that presented in Chapter 8. This chapter does, however, also offer a useful discussion on early versus late word learning and children's dependency on the phonological characteristics of words, as well as comparing rule-based versus child-centred theories. Chapter 13, by Diesendruck, on word learning, follows this and presents a variety of possible mechanisms for this phenomenon, and again has some repeated discussion from Chapter 10. For example, both discuss data on input with noun-bias accounts, but also examine domain-general mechanisms, and suggest that children's biases are not specific to word learning. This chapter concludes with a helpful discussion of how multiple mechanisms might drive word learning at different points in development and in different contexts. This is followed by a chapter by Lidz on syntactic representations and learning, which discusses the nature of symbolic systems, and takes the view that underlying representations of these are equivalent in children and adults, discussing a variety of theories of structure versus performance in child grammar. There are clear and helpful explanations, but little on input or semantic accounts of syntactic development in this age group. In Chapter 15, Siegal and Surian move onto conversational understanding, highlighting its crucial importance not just for the study of child language but for experimental design in many other areas of developmental psychology; for example, appearance-reality tasks, Piagetian theory, and Theory of Mind studies, where children may appear to display conceptual deficits that are in actual fact a failure of pragmatic ability. For example, children often vary their answers despite knowing that the correct answer is the same one they gave earlier, because the experimenter varies their question: one relevant example is of Piagetian conservation experiments, where children are asked twice whether two quantities are the same or different and, having given the answer ‘the same’ the first time, appear to believe a different answer is required the second time, hence concealing any knowledge they may have that the two quantities are still the same. Finally in this section bilingual language acquisition is reviewed by Genesee and Nicoladis.

Part IV concludes the volume with chapters on language beyond early childhood, which is a very helpful inclusion given the implicit assumption of some researchers writing that children reach adult-like language competence at around the age of three years. This section starts with a chapter by Berman on adolescence (including older childhood), discussing how children become proficient speakers (and writers) of their native language, including the development of complex syntax, vocabulary and discourse skills. The chapter also examines how mature language use can be promoted in the classroom, and relates techniques and findings to earlier language development research techniques, which is helpful for those who mainly research younger children's language. One minor criticism is the reliance in this chapter, despite cross-linguistic and cross-cultural data, on US grade levels to indicate children's developmental levels. Chapters 18 and 19 deal with different aspects of the language development and experience of children who are being schooled in a language that is not their home language, or is not their only home language. The first of these chapters, by Oller and Jarmulowicz, examines how one can accurately estimate language abilities in bilingual children, as well as their pattern of strengths and weaknesses in language and other cognitive abilities. The second chapter, by Paradis, looks at how a second language is learned in school-age children, and how this learning contrasts with that of either a younger monolingual or a younger bilingual child. In Chapter 20, Rice examines specific language impairment (SLI), taking a classical definition of the disorder as disrupted language rather than simply delayed language, and examining children's difficulties with finiteness marking. Disappointingly, non-linguistic difficulties and biological aspects of the disorder are not discussed. Chapter 21, by Tager-Flusberg, deals with other disorders in which language development is impaired – Autism, Williams Syndrome and Down Syndrome. This chapter is relatively descriptive rather than theoretical, though it is of course possible that this may reflect the state of knowledge in the study of language in these syndromes. The last chapter, by Lyytinen, Erskine, Aro and Richardson, briefly examines reading and its disorders, discussing typical reading development, how this varies between languages, and theories of dyslexia, before presenting data from a large longitudinal study of children with familial risk of dyslexia. This is a helpful summary of a very large topic, which has its own Blackwell Handbook.

Although the volume has been ostensibly divided by age, rather than by components of language, it seems that some authors found it slightly difficult to write to this brief. Material tends to be repeated in sections on similar topics in different Parts of the Handbook, and authors frequently do not specify the age of children in the studies they discuss, or in some cases discuss studies that are likely to be on children outside the age range with which that particular Part is dealing. In an otherwise excellent volume this is mildly disappointing, though maybe unavoidable. On the whole, even those chapters dealing with theoretically difficult, less mainstream or data-dense topics are readable, well explained and clear. Almost every area of research has been described from a variety of viewpoints (even if not within the same chapter) – there is something for everyone here, regardless of research field or theoretical viewpoint. This makes this volume both an essential addition to the researcher's bookshelf and an ideal source of readings on these topics for advanced undergraduate and postgraduate students.