Chapter 10 appraises the hunting inference about Neanderthal language. Starting from data about Neanderthals’ ambush hunting, this inference comprises in outline three inferential steps: Neanderthals’ ambush hunting had the features F1, F2, F3 and F4 → This hunting required cooperation → This cooperation required communication → This communication required language. [F1 = The hunting was confrontational; F2 = The prey comprised large animals; F3 = Heavy carcasses had to be transported; F4 = Bands of hunters were divided into a tracking/driving and an ambushing group.] The first inferential step is underpinned by the assumption that hunters had to cooperate in planning ambushes, killing dangerous prey etc.; the second step by the assumption that such planning required communication about effective hunting strategies, coordinated action etc.; the third step by the assumption that such communication required ‘labels’ or ‘words’ for referring to features of the landscape, routes, hunting sites etc. These assumptions are reasonable. But it is unwarranted to infer that (a) to be successful, such communication required complex grammar; and (b) that any such communication was not gestural.

Chapter 5 analyses the body-decoration inference about Neanderthal language. This inference includes the following three inferential steps, depicted by the arrows: Blocks of manganese dioxide yielding black pigment were associated with Neanderthal ocupants of sites S1,…,Sn → This pigment was used by these Neanderthals to decorate their bodies → These body decorations had a symbolic function for these Neanderthals → These Neanderthals had language. [Sites S1,…,Sn include Pech d l'Aze I and Pech de l'Aze IV in southern France.] Chapter 5 goes into doubts about the first inferential step of this inference. The main one is that it has not been excluded that the Neanderthals concerned used black pigment for an utilitarian instead of a symbolic function. Black pigment is known to have been used ethnographically and prehistorically for many utilitarian functions. And, importantly, there is experimental evidence that the Neanderthals at Pech de l'Aze I used manganese dioxide for fire-making. Until seccessfully challenged, this finding represents a good reason for doubting the soundness of the second inferential step. This leaves the second and third inferential steps ungrounded.

Chapter 4 elucidates various inferences about Neanderthal language drawn from so-called cave art attributed to Neanderthals. Skeletally, these inferences look as follows, arrows depicting inferential steps: The markings M1,…,Mn are found on the walls of the Iberian caves C1,…,Cn → These markings represent art made by Neanderthal occupants of the caves → This art had a symbolic function for these Neanderthals → These Neanderthals had language. The markings include a hashtag engraving, red disks and hand stencils, a red ladder-shaped sign and red painted mineral deposits. Serious concerns have been expressed about the soundness of these inferences. Two are fundamental. First, the empirical grounding of some are suspect: the dating of the markings is claimed to be inaccurate. This means that some markings may have been made by a modern human rather than a Neanderthal. Second, it has been pointed out, the meanings of the markings are a mystery. This implies that it is unwarranted to infer that these markings were symbols. They could have had a non-symbolic function, which would make the third inferential step ungrounded. Chapter 4 discusses these and other doubts at length.

Chapter 2 sets out the conceptual tools used in the book for analysing selected inferences about Neanderthal language. Derived from The Windows Approach to language evolution, these tools include conditions on the soundness of inferences drawn about something from data about another thing. Such inferences are not necessarily sound. The chapter illustrates three fundamental soundness conditions, using them in an appraisal of a composite inference about the linguistic capacity of European Neanderthals drawn from data about scratches in a number of their anterior teeth. These conditions are: (a) An inferential step must be grounded in factual data; (b) An inferential step must be underpinned by a warrant; and (c) A conclusion must be pertinent, referring to clearly identified and correctly characterised entities. Depicted by arrows, the four steps of the scratched-teeth inference are the following: There are scratches in a number of anterior Neanderthal teeth → Neanderthals ate with the right hand → They were right-handed → They had left-lateralised brains → They had linguistic capacity. The chapter finds the third inferential step to be contentious, and the fourth to be unsound.

Chapter 8 analyses and appraises a modern version of an inference about Neanderthal language drawn from data about the experimental making of stone tools by modern humans. This knapping inference looks skeletally as follows, the arrows depicting inferential steps: Modern humans knap Palaeolithic stone tools by means of action sequences structured in terms of hierarchies and recursion → Like modern humans, Neanderthals knapped stone tools by means of action sequences structured in terms of hierarchies and recursion → Like modern humans, Neanderthals processed language by means of action sequences structured in terms of hierarchies and recursion. Probing the submerged components of this inference, Chapter 8 advances two reasons for doubting its soundness. First, the two inferential steps are poorly warranted, involving weak analologies that disregard important differences between Neanderthals and modern humans. Second, the first inferential step lacks appropriate empirical grounding. That is, the sequences involved in the experimental knapping of stone tools by modern humans are not characterised by the hierarchies and recursion used by the syntax of human language.

Chapter 9 focuses on an inference about Neanderthal language drawn from data about the experimental teaching of stone-tool making to modern humans. Comprising three inferential steps, the knapping-pedagogy inference looks as follows in outline: Experimentally gathered data about the transmission of Oldowan technology to modern humans → Verbal language enhances the transmission of Oldowan technology to modern humans → Verbal language originated hundreds of thousands years ago as a prerequisite for Acheulean technology → Some Neanderthals had verbal language. There are various reasons for doubting the soundness of this inference. First, its empirical grounding is contentious: some experimental studies have found verbal interaction to be unnecessary for teaching knapping skills, even causing underperformance by modern learners. Second, Chapter 9 finds the inferential steps to lack the required logical force. For instance, it cannot be inferred that verbal language was a prerequisite for teaching knapping technology to modern humans from data that it only enhances the teaching of such technology to modern humans. This logical flaw leaves the final inferential step ungrounded.

Chapter 11 elaborates on a number of points argued in preceding chapters. A first concerns the finding that the inferences drawn about Neandertal language from the Neanderthal behaviours at issue are less than sound. This does not imply that Neanderthals could not have had a form of language. Nor does it imply that non-behavioural attributes of Neanderthals provide better windows on their linguistic attributes. This is substantiated by an appraisal of two important inferences about Neanderthal language drawn from putative correspondences between the brains and genes of Neanderthals and those of modern humans. Both the gene and the brain inference are found to be unsound. A second point concerns the roots of the controversial nature of much that has been claimed about Neanderthal language. An often cited one is the lack of uncontentious evidence about Neanderthal language. The root cause, however, lies deeper in a poor conceptual framework that lacks, inter alia, appropriate conditions on the soundness of inferences. A third point concerns the mysterious nature of Neanderthals’ language. Chapter 11 argues that credible inferences about what it involved can be drawn from Neanderthals’ cooperative hunting. It comprised referential signs but lacked complex grammar.

Chapter 1 sets out the concerns, aim, approach and focus of the book, and lists some of its major findings. Its guiding concern is with the lack of uncontroversial answers to questions about the existence and nature of Neanderthal language. Its maim aim is to disperse the murk veiling this phenomenon. For pursuing this aim, the book adopts The Windows Approach to language evolution. In terms of this approach, for claims about Neanderthal language to be credible, they must be conclusions of sound inferences about it. The book, accordingly, unpacks a range of important inferences about Neanderthal language and appraises their soundness. These inferences are drawn from four allegdly symbolic and three non-symbolic behaviours. The book restricts its focus further to inferences about language as a cognitive capacity as distinct from speech as a form of behaviour that presupposes language. To guage the heuristic potential of Neanderthal behaviours as windows on Neanderthal language, the book apparaises in addition the soundeness of important inferences drawn about Neanderthal language from two biological attributes of Neanderthals: the FOXP2 gene and the Broca’s area of the brain.

The range of chronological methods described by the term “luminescence dating” provides a rich set of tools for dating many types of events relevant to archaeological research. These include assessing the depositional age of sediments (the time elapsed since those sediment were deposited by, for example, water, wind, or human activity), and estimating the time since pottery, casting cores, or stones were last fired/heated. Following an initial suggestion by Daniels et al. (1953), luminescence dating methods were introduced into the archaeological context by Aitken et al. (1964) with the thermoluminescence (TL) dating of pottery. Since then, considerable improvements in understanding the basic underlying physical mechanisms have been translated into significant methodological breakthroughs. Notable among these was the development of optically stimulated luminescence (OSL) methods (Huntley et al. 1985) and the improved confidence in dating sedimentary material that this brought. A more recent technologically driven advance was the dating of individual sand grains (so-called single-grain dating), allowing more in-depth assessments of dating reliability and widening the applicability of OSL dating (also referred to as “optical dating”).

The radiocarbon (14C) method underpins most chronologies for the last 50,000 years, due to the accuracy and ubiquity of the technique, suitable for organic material and some carbonates, with uncertainties in the tens to hundreds of years. It is used widely in archaeology, and in studies of past environmental change, but there have been problems to overcome. This chapter outlines the basic principles and examines some of the key developments in the technique.

Because they are highly mineralised, teeth are one of the best preserved and most commonly recovered elements in archaeological and fossil assemblages. They have inspired more than a century of comparative studies of hominin tooth size and shape (e.g., Bailey 2002; Brace et al. 1991; Dubois 1892; Hanihara 2008; Hanihara and Ishida 2005; Hooijer 1948; Irish and Guatelli-Steinberg 2003; Keith 1913; Le Gros Clark 1950; Weidenreich 1937; Wolpoff 1971; Wood et al. 1991). Additional valuable information is recorded on outer surfaces and inner aspects of the dental hard tissues (enamel, dentine, and cementum) that make up tooth crowns and roots, providing a permanent record of growth. Initial study of dental histology, or microscopic tooth structure, predates the fields of archaeology and evolutionary biology by several centuries. The innovative microscopist Anthony Leeuwenhoeck first described the structure of enamel in the 1600s, noting that it was made of longitudinal “pipes” (enamel prisms) that appeared as “globules” when viewed end-on (Leeuwenhoeck 1677–1678). During the 1800s and early 1900s, microscopic investigations revealed the tubular nature of dentine and the presence of successive temporal lines in enamel and dentine (reviewed in Dean 1995; Smith 2006). By the 1940s, American and Japanese teams had experimentally demonstrated the presence of circadian structural features, as well as the neonatal (birth) line, which allows one to relate developmental time to chronological (calendar) age in juvenile dentitions. These incremental features form the basis of a growing area of anthropological study that is illuminating aspects of human evolutionary developmental biology, as well as the health and demography of past human populations.