Ronald Planer

Theorists of human evolution are interested in understanding major shifts in human behavioral capacities (e.g., the creation of a novel technological industry, such as the Acheulean). This task faces empirical challenges arising both from the complexity of these events and the time-depths involved. However, we also confront issues of a more philosophical nature, such as how to best think about causation and explanation. This article considers such fundamental questions from the perspective of a prominent theory of causation in the philosophy of science literature, namely, the interventionist theory of causation. A signature feature of this framework is its recognition of a family of distinct types of causes. We set out several of these causal notions and show how they can contribute to explaining transitions in human behavioral complexity. We do so, first, in a preliminary way, and then in a more detailed way, taking the origins of behavioral modernity as our extended case study. We conclude by suggesting some ways in which the approach developed here might be elaborated and extended.

Tennie, C. & Planer, R.J. Comment on: Stibbard-Hawkes, D. N. E. (in press) "Reconsidering the link between past material culture and cognition in light of contemporary hunter-gatherer material use" in Behavioral and Brain Sciences": Stibbard-Hawkes forcefully alerts us to the pitfall of false negative reasoning in symbolic archaeology. We highlight the twin problem of false positive reasoning in what we call the “false- symbol problem.” False symbols are intuitively special entities that, owing to their non-utilitarian nature, invite symbolic interpretation. But they are not symbolic. We link the false symbol problem to work in comparative primate cognition, taking “primate art” as our main example.

The evolution of human communication and culture are among the most significant--and challenging--questions we face in attempting to understand the evolution of our species. This article takes up two frameworks for theorizing about human communication and culture, namely, Jackendoff's Parallel Architecture of the human language faculty, and the cultural evolutionary framework of Memetics. The aim is to show that the two frameworks uniquely complement one another in some theoretically important ways. In particular, the Parallel Architecture's account of the lexicon significantly expands the range of linguistic phenomena that are plausibly covered by Memetics (e.g., from words to constructions and pure rules of syntax). At the same time, taking a "meme's-eye-view" of the lexicon retools the Parallel Architecture's treatment of the origins and subsequent cultural evolution of language.

In many traditional, small-scale societies, death and other misfortunes are commonly explained as a result of others' malign occult agency. Here, we call this family of epistemic tendencies, "the agential view of misfortune." After reviewing several ethnographic case studies that illustrate this view, we argue that its origins and stability are puzzling from an evolutionary perspective. For not only is the agential view of misfortune false; it imposes costs on individuals and social groups that seem to far outweigh whatever benefits the view might provide. We thus doubt that the agential view of misfortune is explainable in terms of adaptive effects. However, nor does it seem readily explainable as a consequence of belief formation strategies that are on the whole adaptive (as is plausibly the case for certain other of our false beliefs, including some that are costly). Accordingly, we contend that the commonness of the agential view of misfortune demands a special evolutionary explanation of some kind. We provide a partial explanation of this phenomenon by highlighting the adaptive benefits that often flow to occult specialists in environments where the agential view of misfortune is entrenched. What this does not explain, however, is the general lack of resistance we observe in response to occultists' exploitative behaviors over (cultural) evolutionary timescales. We conclude by canvassing a few possible explanations for this puzzling lack of resistance, and while we commit ourselves to none, we do find one option more promising than the others.

Human language sentences are standardly understood as exhibiting considerable hierarchical structure: they can and typically do contain parts that in turn contain parts, etc. In other words, sentences are thought to generally exhibit significant nested part-whole structure. As far as we can tell, this is not a feature of the gestural or vocal communication systems of our great ape relatives. So, one of the many challenges we face in providing a theory of human language evolution is to explain the evolution of hierarchically structured communication in our line. This article takes up that challenge. More specifically, I first present and motivate an account of hierarchical structure in language that departs significantly from the orthodox conception of such structure in linguistics and evolutionary discussions that draw on linguistic theory. On the account I propose, linguistic structure, including hierarchical structure, is treated as a special case of structured action. This account is rooted in the cognitive neuroscience of action, as opposed to (formal) linguistic theory. Among other things, such an account enables us to see how selection for enhanced capacities of act organization and act control in actors, and for act interpretation in observers, might have constructed the brain machinery necessary for the elaborate forms of hierarchically structured communication that we humans engage in. I flesh out this line of thought, emphasizing in particular the role of hominin technique and technology, and the social learning thereof, as evolutionary drivers of this brain machinery.

Culture and communication are widespread in the animal kingdom. However, among apes, only the human line has evolved these into something altogether different. Moreover, our extraordinary cultural and communicative capacities underlie much else of what makes our species stand out among apes. Thus, understanding the how and why of the process by which these capacities were transformed from their great ape-like precursors into their modern human equivalents is of fundamental importance to the challenge of understanding the evolution of our species more generally. In this chapter, we take up these questions using a novel framework for thinking about social learning. We hypothesize that human apes show a unique propensity for a certain type of social learning, which we call "know-how copying." Know-how copying is considered foundational to our species' well-known capacity to culturally evolve both behaviour and artifact forms that can far exceed anything a single individual could realistically invent on his or her own. This copying is therefore also foundational to our species' capacity to construct, maintain and expand the large lexicons of (often) arbitrary signs that underlie human languages. After discussing the various methodologies that are available for testing whether a given type of human or animal culture is demanding of know-how copying, we turn to the archaeological record with an eye towards identifying plausible signatures of the origins of know-how copying in the human line. In particular, we examine the course of hominin technological evolution-as the most visible and most frequent data. We suggest a much later date for the origins of know-how copying than is typically assumed. But this poses a deep puzzle, namely: there is good reason to think that hominins had considerably expanded their communicative repertoire prior to the evolution of know-how copying. How was this possible in the seeming absence of know-how copying? We sketch a solution to this puzzle which we think provides an additional argument in support of a gestural-iconic origins scenario for language.

Grice's analysis of human communication has proven to be highly influential among many philosophers and cognitive scientists, both past and present. At the same time, it has long been recognized that his analysis faces some difficult objections. In particular, a number of theorists have objected to the account Grice provides of the mental states and processes of those engaged in communication. For these theorists, communication as conceived of by Grice has seemed too mentally demanding and complex to be a good general model of human communication. In this article, I consider this challenge afresh from the perspective of Dan Dennett's intentional stance theory. More specifically, I consider some recent remarks Dennett has made in this area, seeking to pin down and clarify his view. I then argue that while Dennett's thinking is on the right track, his view stands in need of both a substantive adjustment and more positive detail. I seek to provide such improvements here. Finally, I consider some of the implications of this improved Dennettian account of Gricean communication for how great ape and human communication are related.

It has seemed to many theorists that our nature as a cooperatively breeding species is crucial to understanding how we became fully human. This article examines a particular strand within this thinking, according to which cooperative breeding drove the evolution of human skills and motivations for sharing intentionality. More specifically, I consider a model of the evolution of these skills and motivations offered by Tomasello and González-Cabrera (2017). Their model is “composite” in that it also recognizes an important role for collaborative foraging in the evolution of shared intentionality. I argue that their model (or more precisely: a natural construal of it) faces at least two problems—what I call the “reflexive metacognition problem” and the “bonding problem.” These two problems (as their names would suggest) concern the cognitive and emotional-motivational dimensions of the evolution of shared intentionality, respectively. I sketch an alternative evolutionary scenario which also posits a dual role for collaborative foraging and cooperative breeding. However, there are some crucial differences between the two models. In particular, the Tomasello and González-Cabrera model appeals to cooperative breeding in explaining the initial appearance of basic skills and motivations for sharing intentionality. In contrast, I argue that cooperative breeding, at least initially, instead served to drive down the age of development of preexisting skills and motivations for sharing intentionality that originally evolved to support collaborative foraging in adult life. This alternative model avoids the reflexive cognition and bonding problem, and has other advantages which I highlight.

This commentary seeks to supplement the case Quilty-Dunn et al. make for the psychological reality of languages of thought in two ways. First, it focuses on the reduced physical demands which language-of-thought architectures often make compared to alternative architectures. Second, it embeds language-of-thought research within a broader framework that can be leveraged to understand the evolution of languages of thought.

While the term "metacognition" is sometimes used to refer to any form of thinking about thinking, in cognitive psychology, it is typically reserved for thinking about one's own thinking, as opposed to thinking about others' thinking. How metacognition in this more specific sense relates to otherdirected mindreading is one of the main theoretical issues debated in the literature. This article considers the idea that we make use of the same or a largely similar package of resources in conceptually interpreting our own mind as we do in interpreting others'. I assume that a capacity for other-directed mindreading is minimally shared with our great-ape relatives, but I argue that the architecture of this system had to be substantially modified before it could efficiently and adaptively be turned inwards on one's own mind. I contend that an important piece of the overall evolutionary explanation here likely concerns selection pressures arising from the domain of conversational interaction. Specifically, drawing on work carried out in the human interaction studies tradition (e.g., conversation analysis), I argue that the smooth to-and-fro of conversational interaction can be seen to heavily depend on metacommunicative capacities, which, in turn, are underpinned by metacognitive capacities. I conclude with a thumbnail sketch of an evolutionary account of the emergence of these metacognitive capacities in the human line. Their appearance and spread-whether via genes, cultural learning, or more likely, some combination of the two-helps to explain the transition from great-ape communication to human conversation.

This chapter (i) begins by emphasising the differences between the social lives of animals (primarily chimps) and those of humans (including humans in deep time). Human social life depends on persistent, collective organisational features of communities (for example, their multi-level character and their economic inter-dependence). (ii) The chapter nevertheless argues that chimp social lives have robust supra-individual, collective features. (iii) These evolve as aggregate outcomes of individual-level selection, but once they emerge, they change the selective landscape. (iv) The chapter then briefly reviews ideas about the evolution of the much more diverse and complex collective features of even the simplest human communities, and (v) discusses ways of integrating methodological individualism with a recognition of the importance of these collective phenomena. (vi) The chapter concludes with a summary and some directions for future research in the area of social ontology and human evolution.

To appear in Explorations in Archaeology and Philosophy (ed. Killin, A., & Allen-Hermanson, S.): There is growing acceptance among language evolution researchers that an increase in our ancestors' theory of mind capacities was critical to the origins of language. However, little attention has been paid to the question of how those capacities were in fact upgraded. This article develops a novel hypothesis, grounded in contemporary cognitive neuroscience, on which our theory of mind capacities improved as a result of an increase in our System-2 thinking capacities, in turn based in an increase in our working memory capacities. I contrast this hypothesis with what would appear to be the default position among language evolution researchers, namely, that our theory of mind became more powerful as a result of genetic change to a domain-specific mindreading system which we share with other great apes. While the latter hypothesis is not implausible, it arguably enjoys less empirical support at present than does the alternative hypothesis I develop.

An essay review of Richard Wrangham's "The Goodness Paradox". I summarize and then evaluate the book’s overall argument. I pay special attention to Wrangham's ideas about connections between human self-domestication and the evolution of language and cooperation.

Kinship plays a foundational role in organizing human social behavior on both local and more global scales. Hence, any adequate account of the evolution of human sociality must include an account of the evolution of human kinship. This article aims to make progress on the latter task by providing a few key pieces of an evolutionary model of kinship systems. The article is especially focused on the connection between primate social cognition and the origins of kinship systems. I argue that early conceptions of kinship in our line were very likely scaffolded by preexisting forms of primate social cognition. It was only later, as linguistic resources increased in our line, and as human social life grew more complex, that these conceptions came to resemble kin categories as we now know them. I conclude by situating “kin cognition” within a broader cognitive science framework for studying capacities that reflect both innate knowledge and human cultural learning.

The idea that cognition makes use of one or more "languages of thought" remains central to much cognitive-scientific and philosophical theorizing. And yet, virtually no attention has been paid to the question of how a language of thought might evolve in the first place. In this article, I take some steps towards addressing this issue. With the aid of the so-called Sender-Receiver framework, I elucidate a family of distinctions and processes which enable us to see how languages of thought might evolve via a series of small, incremental changes. While much work doubtlessly remains to be done in this area, I hope to at least show that there need be nothing mysterious about the existence of languages of thought on evolutionary grounds.

Humans' capacity for so-called symbolic cognition is often invoked by evolutionary theorists, and in particular archeologists, when attempting to explain human cognitive and behavioral uniqueness. But what is meant by "symbolic cognition" is often left underspecified. In this article, I identify and discuss three different ways in which the notion of symbolic cognition might be construed, each of them quite distinct. Getting clear on the nature of symbolic cognition is a necessary first step in determining what symbolic cognition might plausibly explain.

Modeling work by Brian Skyrms and others in recent years has transformed the theoretical role of David Lewis's 1969 model of signaling. The latter can now be understood as a minimal model of communication in all its forms. In this article, we explain how the Lewis model has been generalized, and consider how it and its variants contribute to ongoing debates in several areas. Specifically, we consider connections between the models and four topics: the role of common interest in communication, signaling within the organism, meaning, and the evolution of human communication and language. The orientation to communication and representation created by these models, what we call "the sender-receiver framework," treats coordination between behaviors of sign production and interpretation as the core phenomenon of communication. In some cases, that coordination will be the product of intentional foresight and agency, while in others it will be due to simpler selective processes operating over phylogenetic, ontogenetic, or cultural timescales. The unifying character of this framework also depends on its recognizing both clear and partial cases of sender-receiver systems, where this is understood in terms of how closely a real-world system matches the entities and relations treated by the models.

This paper examines some recent work by Robert Berwick and Noam Chomsky as presented in their book "Why Only Us? Language and Evolution" (2015). As I understand them, Berwick and Chomsky's overarching purpose is to explain how human language could have arisen in so short an evolutionary period. After articulating their strategy, I argue that they fall far short of reaching this goal. A co-evolutionary scenario linking the mechanisms that realize the language system, both with one other and with cognitive mechanisms capable of exploiting linguistic expressions, is surely unavoidable. And yet this is precisely what B&C in effect rule out.

Discussion item. Looks at the relationship between two hypotheses attempting to explain the evolution of Erectine anatomical and behavioral innovations (the "cooking hypothesis" and the "mechanical processing hypothesis"). Connects a regime of mechanical processing of plant foods using wooden implements and platforms to the discovery of primitive ignition technology.

The purpose of this paper is to critically engage with a recent attempt by Thom Scott- Phillips to offer a general account of communication. As a general account, it is intended to apply equally well to both non-human and human interactions which are prima facie communicative in character. However, so far, Scott-Phillips has provided little detail regarding how his account is supposed to apply to the latter set of cases. After presenting what I take to be the most plausible way of filling in those details, I argue that his account would appear to be too narrow: it (minimally) fails to capture a range of human interactions which strike us as instances of communication. To wit, these are cases in which some but not all of the information an act is designed to convey to a reactor actually reaches that reactor. An alternative account incorporating Scott-Phillips' main insights is then sketched, and it is suggested that this account, or something like it, would accommodate the full range of non-human and human interactions that are intuitively communicative.

This paper addresses the question of whether early Pleistocene hominins are plausibly viewed as having possessed a protolanguage, that is, a communication system exemplifying some but not all of the distinctive features of fully-modern human language. I argue that the answer is “yes” mounting evidence from the early Pleistocene “lithics niche”. More specifically, I first describe a cognitive platform which I think would have been sufficient, given appropriate socio-ecological conditions, for the creation and retention of a protolanguage. Then, using archeological evidence pertaining to hominin lithic behavior from the early Pleistocene, I attempt to make plausible the idea that each of these cognitive abilities were in fact in place by this point in hominin evolutionary history and also that the requisite socio-ecological conditions were satisfied.

According to one currently influential line of thinking, the evolution of ostensive communication was a prerequisite for the evolution of human language. In this article, I distinguish between a strong and a weak version of this view and offer a sustained argument against the former. More specifically, the strong version of this view would have it that ostensive communication was a prerequisite not just for the evolution of fully modern language but for any language-like system of communication. I argue that this version is too strong: I show how some distinctive and important features of language may well have been assembled prior to the evolution of ostensive communication. Put another way, I argue that a protolanguage before ostensive communication scenario is a real possibility. I conclude by briefly arguing that such an evolutionary scenario coheres better with archaeological evidence from the early Pleistocene as well as evidence from developmental psychology pertaining to the nature of our mind reading abilities.

Samuel Bowles and Herbert Gintis have argued that individual-selection accounts of human cooperation flounder in the face of the free-rider identification problem. Kim Sterelny has responded to this line of argument for group selection, arguing that the free-rider identification problem in fact poses no theoretical difficulty for individual-selection accounts. In this article, I set out to clarify Bowles and Gintis’ argument. As I see matters, the real crux of their argument is this: solving the free-rider identification problem, even in modestly sized social groups, requires that group members are disposed to share social information with one another. The difficulty for individual-selection accounts, according to Bowles and Gintis, is that these accounts have no explanation for why individuals should be disposed to behave in this way. Having clarified their argument, I then turn to Sterelny’s criticism, and argue that Sterelny underestimates the challenge being raised by Bowles and Gintis. More specifically, I argue that it is unclear whether the expected benefits of having a disposition to share social information would have outweighed the expected costs for an individual belonging to a Pleistocene social group. Importantly, this is not to say that I am persuaded by Bowles and Gintis’ argument; on the contrary, what I claim is that more theoretical (and in particular) empirical work is necessary before the issues under discussion can be settled. I formulate some specific questions which I think future research in this area should aim to address.

The status of genes as bearers of semantic content remains very much in dispute among philosophers of biology. In a series of papers, Nicholas Shea has argued that his ‘infotel’ theory of semantics vindicates the claim that genes carry semantic content. On Shea’s account, each organism is associated with a ‘developmental system’ that takes genetic representations as inputs and produces whole-organism traits as outputs. Moreover, at least in his most recent work on the topic, Shea is explicit in claiming that these genetic representations are ‘read in ontogenetic time, in the course of individual development’. Here I argue that a close examination of the process of reading, in Shea’s sense, reveals that acts of reading do not actually occur over the course of developmental time at all. To make this vivid, I contrast the process of reading for Shea with another type of developmental process that is widely seen as a form of reading directed on inherited genes, and which certainly does occur over the course of developmental time, namely, gene expression. I suggest that this error in Shea’s thinking can be traced back to an equivocation on Shea’s part in the meaning of ‘reads’, and also to a reliance on an invalid principle regarding the transference of representational content from one token gene to another. The issues at play are bound up with questions about causation and in particular about causation over time. Thus, having first presented my arguments in a way that doesn’t depend on any particular theory of causation, I then make use of Kenneth Waters’ framework of difference-making causation to conceptually sharpen and shed further light on matters. I conclude by discussing a consequence of the fact that acts of reading do not occur in development.

Talk of a “genetic program” has become almost as common in cell and evolutionary biology as talk of “genetic information”. But what is a genetic program? I understand the claim that an organism’s genome contains a program to mean that its genes not only carry information about which proteins to make, but also about the conditions in which to make them. I argue that the program description, while accurate in some respects, is ultimately misleading and should be abandoned. After that, I sketch an alternative framework which is better suited to capturing the full informational nature of genes. This framework is centered on the notion of a signaling game, as originally developed by David Lewis, but expanded upon considerably by Brian Skyrms in more recent years. On the view I develop, genes turn out to be the producers and consumers of regulatory or developmental information, rather than entities encoding such information. This finding has consequences that link up with a broader debate in the philosophy of biology concerning inheritance systems. I take this to be one form of theoretical payoff that results from applying the signaling games framework to genes