“Nature” or “Nurture”?

The nature–nurture debate can be traced back to the literature more than two thousand years ago, particularly significant in the writings of Greek philosopher Plato (Samet, 2019). The discussion between Plato and Aristotle (i.e., rationalism or empiricism) lays the foundation for the debate that continues to this day. The debate includes two opposing viewpoints. The nature view states that all human knowledge and behaviors guided by knowledge are innate (Chomsky, 1959), and the nurture view argues that all human knowledge and behaviors are acquired through postnatal learning and affected by environmental factors, such as the influence of parents, educational experience, and life practices (Skinner, 1957). Numerous scholars have proposed a number of insightful ideas between these two extreme all-or-nothing views. Over the past few decades, studies of the nature–nurture debate have focused primarily on linguistics and psychology. Some scholars tend to explore the roles of innate and acquired factors in human behavior and mental development and thus make their readers accept their viewpoints or defend one side of the debate. Scholars can acquaint themselves with this controversy by reading the book A Mind for Language: An Introduction to the Innateness Debate.Based on an interdisciplinary approach, the book comprehensively elaborates the debate in an accessible way. It provides researchers interested in the nature–nurture debate with a panorama and sufficient background information. Except for the “Introduction” and “Winding Up,” the main body of the book is divided into four parts (Part II–Part V). Part II (Chapters 2–5) introduces the general background of the nature–nurture debate, Part III (Chapters 6–8) provides readers with an understanding of language from the linguistics perspective, Part IV (Chapters 9–12) further introduces various arguments in favor of the innateness hypothesis in the context of first language acquisition, and Part V (Chapter 13) discusses the applicability of the arguments mentioned in Parts III and IV through the lens of the modality of sign language.The book begins with the background, successively introduces specific theories and hypotheses, and finally discusses their applications. The arrangement indicates the author's writing logic, namely, from the general to the specific, so that readers can systematically understand the content and viewpoints presented in the book.Part I begins with an overview of the nature–nurture debate. The author introduces the concept of “innate” and one of the intriguing issues about the debate: Besides universal grammar (factor 1) and the input (factor 2), what is the “third factor” that influences the structure of mental grammars? Based on the issue, the author further brings forward his own insights into the fascinating debate. He firmly believes that humans possess a “mind for language.” Additionally, the part also presents the overall structure of the book, which can help readers understand the author's writing sequence.Part II introduces the background of the nature–nurture debate, covering the perspectives of history, philosophy, and modern science. Specifically, Chapter 2, from a historical aspect, summarizes the diverse viewpoints and arguments held by scholars in the nature–nurture debate and particularly focuses on Chomsky's innateness hypothesis for language. Chapter 3 explores the nature–nurture debate within a philosophical context. By analyzing the different interpretations of empiricism and rationalism on the nature of mind and the origins of knowledge, the chapter reveals the profound philosophical background, especially the philosophical origins and historical development, of the debate in question. Chapter 4 focuses on cognitive science, one of the booming fields, and highlights its immense potentials in driving technological innovation through examples from emerging fields such as artificial intelligence (AI), computer science, and cryptology. This demonstrates the flourishing trend of mind research from an interdisciplinary perspective. In addition, the chapter introduces the multidimensional levels of mind research, such as the functional/computational level, the symbolic/algorithmic level, and the physical/implemental level, which not only broadens the breadth of the mind research but also deepens readers’ understanding of the complexity of mind. Chapter 5 presents the notion of mental module. It depicts Jerry Fodor's criteria for identifying the “true” mental modules and in succession delineates the distinctions between modest modularity and massive modularity (e.g., modest modularity focuses on input systems, whereas massive modularity focuses on the whole cognitive system).Part III canvasses three core issues—mental grammar, language universals, and language change—from a linguistics perspective. In Chapter 6, readers can gain an understanding of the language structure and subsequently the mental grammar that underlies language utterances. By learning the structure of mental grammar, readers can better appreciate the complexity of language and gain an insight into the knowledge system that children must acquire to effectively master a language. Chapter 7 concentrates on the issue of whether language universals (i.e., properties shared by all languages) exist. It sheds light on the notion of covert and overt universals and explains language universals from multiple perspectives, including efficiency, cognitive, biological, and historical explanations. In addition, the chapter also assesses the extent to which language universals support the innateness hypothesis. Although many universals can be explained without appealing to language-specific innate systems, certain universal properties remain unaccounted for. The existence of these properties, such as structure dependency and binarity, could support the plausibility of the innateness hypothesis, but only if these properties are specific to language. Chapter 8 begins with an engaging story to portray the differences between external language (E-language) and internal language (I-language). E-language refers to the utterance, whereas I-language involves the underlying grammatical rules and mental representations. Furthermore, the chapter focuses on various questions about language change with examples. Language changes all the time, and thus it becomes a challenging task to read Shakespeare's works not only for today's English learners but also for native speakers. However, despite changes in all kinds of languages, their properties remain within the universal design, indicating that these properties are constant to a certain degree. Based on the innateness hypothesis, the author explains why these properties are immune to change, suggesting that they must be anchored in an innate system.Part IV introduces various arguments about the innateness hypothesis from a first language acquisition perspective. Chapter 9 first reviews the specific theoretical model proposed by Chomsky, which aims to explain why children can master a language easily. Chomsky (1959) believes that the basic properties of grammar are innate and can be acquired spontaneously. He also proposes the notion of “parameter,” providing the possibility for children to select and acquire specific language based on their language input. The chapter then discusses the concept that there is a significant discrepancy between the language input children receive and the mental grammar they actually master. The distinction makes it difficult to explain the process of children's first language acquisition based just on language input. Chomsky (1959) believes that there must be something that bridges the gap between the limited language input and the complex mental grammar of children. In addition, the chapter explores the phenomenon of language convergence, that is, under the premise of same language environment, children receive diverse language inputs yet ultimately develop a fundamentally consistent mental grammar. The author concludes that if such convergence is confirmed, it will further indicate that children's mental grammar does not rely on language input but a shared innate system. The chapter also presents some counterarguments to the innateness hypothesis. For instance, behaviorist B. F. Skinner (1957) argues that children learn language entirely based on exposure to language utterances (the stimuli) and certain responses (trials) that are reinforced either positively (rewarded, e.g., by getting what they desire) or negatively (punished, e.g., by not getting what they desire). Additionally, another approach to learning, known as connectionism, emphasizes the role of environmental factors in shaping cognition. Since its introduction as an alternative to nativism, connectionism has gained significant popularity (Bates et al., 1996).Chapter 10 unfolds the stages of language acquisition from various perspectives, ranging from phonology to semantics. It is a common phenomenon that children go through a series of specific stages before fully mastering their first language. In these stages, children's language systems gradually “mature,” and each advancement occurs within a specific time frame determined by biological factors (nature) rather than by external factors (nurture).Chapter 11 introduces the critical period of language acquisition. Although the author cannot display a consensus shared by scholars on the exact boundaries of such a period, it is commonly accepted that for human language, the period ends around puberty. The conclusion is drawn primarily from the analysis of existing cases, among which the American girl Genie is notable. Genie, who had been captive for more than 12 years and forbidden from vocalizing, was 13 years old (postpuberty) when discovered. After that, Genie received language rehabilitation. However, she failed to attain age-appropriate linguistic proficiency. This demonstrates the necessity of the critical period for activating innate language capacities that enable children in normal situations to rapidly become fluent language users.Chapter 12 introduces the creolization argument, which claims that when children are exposed to pidgin (i.e., a primitive communication system created by adults who do not share a common language), they can spontaneously turn the primitive language to a mature language, namely creole. The study of pidgins and creoles provides us with an unexpected argument in favor of the innateness hypothesis. Given that children can construct a complete mental grammar that delivers a complete language based on the limited language input, it must be the case that there is a fairly specific and articulated innate system. Such a system takes the impoverished input as a trigger to construct a full language system. Specifically, what a pidgin passes down to children is a set of words and form-meaning packages, whereas the innate system installs a fuller language scheme, filling up the “gaps” in the pidgin system. However, linguists with an empirical view favor the gradualist hypothesis. Without denying that children can introduce innovations, the hypothesis emphasizes that pidgins gradually gain complexity when used by several subsequent generations of speakers. The central view of the hypothesis is that the increasing complexity of pidgin is mainly due to its use in more and more circumstances, which naturally causes it to become richer lexically and grammatically. Additionally, linguist Guy Deutscher (2006) argues that a protolanguage system can develop into full-fledged languages without appealing to any genetically based innate universal grammar. He believes that the grammaticalization processes observable in the history of all languages are sufficient to explain how modern language structures have come about.Part V is concerned with sign language. As an independent and full-fledged language modality, sign language is equally complex and complete in its structure and function as spoken language. In Chapter 13, the author lists 11 misunderstandings about sign language that have long been held by the public and reveals that there is a great similarity between sign and spoken languages in their structure and communicative properties. For example, both of them have a lexicon with many words and have a syntactic system. Moreover, the various arguments of spoken language discussed in the previous chapters of the book can also apply to sign language. Children who receive sign language input from birth show significant similarity in the developmental pattern with these who receive spoken language input in language acquisition. Furthermore, the author points out the similarities between spoken and sign languages in terms of developmental stages, functions (e.g., expressive function, informative function), and grammar structures, which all strongly indicate that they come from a shared innate language system. The author also presents another physiological argument that spoken and sign languages are processed in the same areas of the brain, which further reinforces the view that sign language is homologous to spoken language. Based on the above discussion, the author suggests that it is natural to deem sign language itself as a piece of evidence for the innateness of language.However, in the chapter, the author also presents empirical evidence challenging the notion that language is determined by a genetically based innate system. Linguist Judy Kegl's study on Nicaraguan Sign Language illustrates this point (Kegl et al., 1999). She compares the acquisition level of Nicaraguan Sign Language between teenagers and younger children, finding that the younger group exhibits remarkable fluency with well-defined grammatical structure. The reason for this is that the younger children are at the appropriate age to start acquiring their first language, with input from the older generation (teenagers). The case highlights the importance of postnatal language input and the critical period in linguistic development. Additionally, cross-linguistic analyses of sign languages reveal significant lexical and grammatical variations, such as different signs for “woman” in American Sign Language (“bonnet” + “person”), in Israeli Sign Language (“earring”), and in some European sign languages (“breasts” or “body shape”). These variations suggest that language is a product of cultural evolution, with its complexity and diversity arising from innovations and adjustments during intergenerational transmission.The final part of the book, “Winding Up,” provides a comprehensive review and evaluation of the various arguments discussed in the previous chapters in an interesting “forum” form. The fictional dialog in such a forum is full of inspiration, which assists in enhancing readers’ comprehension of the nature–nurture debate. The part also outlines the arguments that will be discussed in the author's sequel, Genes, Brains and Evolution: The Language Debate Continued. In this forthcoming book, the author will step out of the linguistic perspective and extensively explore the various fields such as neuroscience, genetics, the study of animal communication systems, and the evolution of our species, aiming to further explore evidence that favors the innateness hypothesis.Generally, the most prominent feature of A Mind for Language is its adoption of an interdisciplinary approach to introducing the innateness hypothesis in detail. The book not only systematically elaborates the relevant theories of the hypothesis but also supports them with abundant examples, thus achieving an organic combination of theory and practice. Therefore, the book can serve as a valuable resource for scholars in linguistics and other related fields. It also bridges the gap between theory and practice of the hypothesis for students without a linguistic background.First of all, the interdisciplinary approach of this book breaks down the barriers between disciplines, which promotes not only the development of new theories and research methods but the fascinating debate as well. This is reflected in the ethological studies, which provide evidence for the innateness hypothesis for language. For instance, the author canvasses the innateness of “instinct” and cognitive mechanisms. He not only reveals the innate characteristics based on Konrad Lorenz's (1977) observation of animal behavior but also provides analogies and support for the innateness hypothesis for language. Moreover, the interdisciplinary approach promotes the integration of theory and practice, applying abstract theories to multiple fields such as artificial intelligence, ethology, criminology, and cryptology (e.g., in the field of cryptology, the concepts from information theory are used to design secure encryption protocols), which means that theories are no longer limited to abstract discussions but can have a significant impact on humans and society. It is also one of the significant trends in future language research (e.g., the research combining language and data science).Second, the book provides numerous real-life examples to illustrate related theories, assisting readers in understanding these abstract theoretical concepts. Although scholars have studied the innateness hypothesis fairly extensively, how to effectively explicate the theoretical concepts within innateness hypothesis in a concise manner has always been a tough question. The book makes pioneering contributions in this regard through abundant examples. For example, in Chapter 8, the author takes the change and split of Proto-Indo-European as an example to illustrate that, despite constant change, languages are all faithful to some of the fundamental grammatical design properties and universals. Chapter 11 narrates various examples, particularly the American girl Genie (Curtiss, 1977), which vividly illustrate the existence of a critical period of language learning. All these examples form a solid foundation for understanding the concept of language and the innateness hypothesis.Finally, the author has taken various techniques to enhance the readability and practicability of the book, aiming to expand the readership and further provide enough background knowledge for readers to participate in the never-ending debate. In terms of language, whether in describing theories or analyzing examples, the author uses clear and accessible language so that readers with little background in linguistics can also read it fluently. As for the structure, the author uses a logical framework of “deduction and summary.” The book starts with an overview of the central theme, the overall structure of the book, and subsequently the general background of the nature–nurture debate, accompanied by various relevant arguments. In the final part, the author adopts the pioneering “forum” form to review these arguments presented in previous chapters. For readers, such an arrangement is conducive to understanding the main points of the book. With regard to learning aids, the website that comes with the book offers a glossary, questions for reflection, discussion themes, and project suggestions to help readers better understand the book.All in all, the book provides valuable resources for readers to understand and even participate in the nature–nurture debate. Readers will obtain abundant knowledge about the essence and features of human language and ultimately achieve a more comprehensive and in-depth understanding of the nature–nurture debate.