Human musical capacity and products should have been induced by the hominin-specific combination of several biosocial features: A three-phase scheme on socio-ecological, cognitive, and cultural evolution

Various selection pressures have shaped human uniqueness, for instance, music. When and why did musical universality and diversity emerge? Our hypothesis is that "music" initially originated from manipulative calls with limited musical elements. Thereafter, vocalizations became more complex and flexible along with a greater degree of social learning. Finally, constructed musical instruments and the language faculty resulted in diverse and context-specific music. Music precursors correspond to vocal communication among nonhuman primates, songbirds, and cetaceans. To place this scenario in hominin history, a three-phase scheme for music evolution is presented herein. We emphasize (1) the evolution of sociality and life history in australopithecines, (2) the evolution of cognitive and learning abilities in early/middle Homo, and (3) cultural evolution, primarily in Homo sapiens. Human musical capacity and products should be due to the hominin-specific combination of several biosocial features, including bipedalism, stable pair bonding, alloparenting, expanded brain size, and sexual selection.

Cultural evolution: A review of theoretical challenges

The rapid growth of cultural evolutionary science, its expansion into numerous fields, its use of diverse methods, and several conceptual problems have outpaced corollary developments in theory and philosophy of science. This has led to concern, exemplified in results from a recent survey conducted with members of the Cultural Evolution Society, that the field lacks 'knowledge synthesis', is poorly supported by 'theory', has an ambiguous relation to biological evolution and uses key terms (e.g. 'culture', 'social learning', 'cumulative culture') in ways that hamper operationalization in models, experiments and field studies. Although numerous review papers in the field represent and categorize its empirical findings, the field's theoretical challenges receive less critical attention even though challenges of a theoretical or conceptual nature underlie most of the problems identified by Cultural Evolution Society members. Guided by the heterogeneous 'grand challenges' emergent in this survey, this paper restates those challenges and adopts an organizational style requisite to discussion of them. The paper's goal is to contribute to increasing conceptual clarity and theoretical discernment around the most pressing challenges facing the field of cultural evolutionary science. It will be of most interest to cultural evolutionary scientists, theoreticians, philosophers of science and interdisciplinary researchers.

Conditions under which faithful cultural transmission through teaching promotes cumulative cultural evolution

It has been argued that teaching promotes the accurate transmission of cultural traits and eventually leads to cumulative cultural evolution (CCE). However, previous studies have questioned this argument. In this study, we modified the action sequences model into a network exploring model with reinforcement learning to examine the conditions under which teaching promotes CCE. Our model incorporates a time trade-off between innovation and teaching. Simulations revealed that the positive influence of teaching on CCE depends on task difficulty. When the task was too difficult and advanced, such that it could not be accomplished through individual learning within a limited time, spending more time on teaching-even at the expense of time for innovation-contributed to CCE. On the contrary, the easier the task, the more time was spent on innovation than on teaching, which contributed to the improvement of performance. These findings suggest that teaching becomes more valuable as cultures become more complex. Therefore, humanity must have co-evolved a complex cumulative culture and teaching that supports cultural fidelity.

The cultural evolution of teaching

Teaching is an important process of cultural transmission. Some have argued that human teaching is a cognitive instinct - a form of 'natural cognition' centred on mindreading, shaped by genetic evolution for the education of juveniles, and with a normative developmental trajectory driven by the unfolding of a genetically inherited predisposition to teach. Here, we argue instead that human teaching is a culturally evolved trait that exhibits characteristics of a cognitive gadget. Children learn to teach by participating in teaching interactions with socialising agents, which shape their own teaching practices. This process hijacks psychological mechanisms involved in prosociality and a range of domain-general cognitive abilities, such as reinforcement learning and executive function, but not a suite of cognitive adaptations specifically for teaching. Four lines of evidence converge on this hypothesis. The first, based on psychological experiments in industrialised societies, indicates that domain-general cognitive processes are important for teaching. The second and third lines, based on naturalistic and experimental research in small-scale societies, indicate marked cross-cultural variation in mature teaching practice and in the ontogeny of teaching among children. The fourth line indicates that teaching has been subject to cumulative cultural evolution, i.e. the gradual accumulation of functional changes across generations.

Teaching unleashes expression

I propose that the evolution of teaching has been central in extending manipulative intentions. Demonstrating may be the evolutionarily first form of expression that is productive, ostensive, and involves informative intention. Demonstration also involves theory of mind. Then pantomime goes a step further and involves a communicative intention. Pantomime can thereby function as displaced communication used for more complex expressions.

The co-evolution of cooperation and communication: Alternative accounts

We challenge the proposal that partner-choice ecology explains the evolutionary emergence of ostensive communication in humans. The good fit between these domains might be because of the opposite relation (ostensive communication promotes the evolution of cooperation) or because of the dependence of both these human-specific traits on a more ancient contributor to human cognitive evolution: the use of technology.

Inferring cultural reproduction from lithic data: A critical review

The cultural reproduction of lithic technology, long an implicit assumption of archaeological theories, has garnered increasing attention over the past decades. Major debates ranging from the origins of the human culture capacity to the interpretation of spatiotemporal patterning now make explicit reference to social learning mechanisms and cultural evolutionary dynamics. This burgeoning literature has produced important insights and methodological innovations. However, this rapid growth has sometimes led to confusion and controversy due to an under-examination of underlying theoretical and methodological assumptions. The time is thus ripe for a critical assessment of progress in the study of the cultural reproduction of lithic technology. Here we review recent work addressing the evolutionary origins of human culture and the meaning of artifact variation at both intrasite and intersite levels. We propose that further progress will require a more extended and context-specific evolutionary approach to address the complexity of real-world cultural reproduction.

Environmental influences on human innovation and behavioural diversity in southern Africa 92-80 thousand years ago

Africa's Middle Stone Age preserves sporadic evidence for novel behaviours among early modern humans, prompting a range of questions about the influence of social and environmental factors on patterns of human behavioural evolution. Here we document a suite of novel adaptations dating approximately 92-80 thousand years before the present at the archaeological site Varsche Rivier 003 (VR003), located in southern Africa's arid Succulent Karoo biome. Distinctive innovations include the production of ostrich eggshell artefacts, long-distance transportation of marine molluscs and systematic use of heat shatter in stone tool production, none of which occur in coeval assemblages at sites in more humid, well-studied regions immediately to the south. The appearance of these novelties at VR003 corresponds with a period of reduced regional wind strength and enhanced summer rainfall, and all of them disappear with increasing winter rainfall dominance after 80 thousand years before the present, following which a pattern of technological similarity emerges at sites throughout the broader region. The results indicate complex and environmentally contingent processes of innovation and cultural transmission in southern Africa during the Middle Stone Age.

Shared intentionality, reason-giving and the evolution of human culture

The biological approach to culture focuses almost exclusively on processes of social learning, to the neglect of processes of cultural coordination including joint action and shared intentionality. In this paper, we argue that the distinctive features of human culture derive from humans' unique skills and motivations for coordinating with one another around different types of action and information. As different levels of these skills of 'shared intentionality' emerged over the last several hundred thousand years, human culture became characterized first by such things as collaborative activities and pedagogy based on cooperative communication, and then by such things as collaborative innovations and normatively structured pedagogy. As a kind of capstone of this trajectory, humans began to coordinate not just on joint actions and shared beliefs, but on the reasons for what we believe or how we act. Coordinating on reasons powered the kinds of extremely rapid innovation and stable cumulative cultural evolution especially characteristic of the human species in the last several tens of thousands of years. This article is part of a discussion meeting issue 'The emergence of collective knowledge and cumulative culture in animals, humans and machines'.

Expression unleashed: The evolutionary and cognitive foundations of human communication

Human expression is open-ended, versatile, and diverse, ranging from ordinary language use to painting, from exaggerated displays of affection to micro-movements that aid coordination. Here we present and defend the claim that this expressive diversity is united by an interrelated suite of cognitive capacities, the evolved functions of which are the expression and recognition of informative intentions. We describe how evolutionary dynamics normally leash communication to narrow domains of statistical mutual benefit, and how expression is unleashed in humans. The relevant cognitive capacities are cognitive adaptations to living in a partner choice social ecology; and they are, correspondingly, part of the ordinarily developing human cognitive phenotype, emerging early and reliably in ontogeny. In other words, we identify distinctive features of our species' social ecology to explain how and why humans, and only humans, evolved the cognitive capacities that, in turn, lead to massive diversity and open-endedness in means and modes of expression. Language use is but one of these modes of expression, albeit one of manifestly high importance. We make cross-species comparisons, describe how the relevant cognitive capacities can evolve in a gradual manner, and survey how unleashed expression facilitates not only language use, but also novel behaviour in many other domains too, focusing on the examples of joint action, teaching, punishment, and art, all of which are ubiquitous in human societies but relatively rare in other species. Much of this diversity derives from graded aspects of human expression, which can be used to satisfy informative intentions in creative and new ways. We aim to help reorient cognitive pragmatics, as a phenomenon that is not a supplement to linguistic communication and on the periphery of language science, but rather the foundation of the many of the most distinctive features of human behaviour, society, and culture.

On the Neurocognitive Co-Evolution of Tool Behavior and Language: Insights from the Massive Redeployment Framework

Understanding the link between brain evolution and the evolution of distinctive features of modern human cognition is a fundamental challenge. A still unresolved question concerns the co-evolution of tool behavior (i.e., tool use or tool making) and language. The shared neurocognitive processes hypothesis suggests that the emergence of the combinatorial component of language skills within the frontal lobe/Broca's area made possible the complexification of tool-making skills. The importance of the frontal lobe/Broca's area in tool behavior is somewhat surprising with regard to the literature on neuropsychology and cognitive neuroscience, which has instead stressed the critical role of the left inferior parietal lobe. Therefore, to be complete, any version of the shared neurocognitive processes hypothesis needs to integrate the potential interactions between the frontal lobe/Broca's area and the left inferior parietal lobe as well as their co-evolution at a phylogenetic level. Here, we sought to provide the first elements of answer through the use of the massive deployment framework, which posits that evolutionarily older brain areas are deployed in more cognitive functions (i.e., they are less specific). We focused on the left parietal cortex, and particularly the left areas PF, PGI, and anterior intraparietal (AIP), which are known to be involved in tool use, language, and motor control, respectively. The deployment of each brain area in different cognitive functions was measured by conducting a meta-analysis of neuroimaging studies. Our results confirmed the pattern of specificity for each brain area and also showed that the left area PGI was far less specific than the left areas PF and AIP. From these findings, we discuss the different evolutionary scenarios depicting the potential co-evolution of the combinatorial and generative components of language and tool behavior in our lineage.

The Cognitive Science of Technology

Technology is central to human life but hard to define and study. This review synthesizes advances in fields from anthropology to evolutionary biology and neuroscience to propose an interdisciplinary cognitive science of technology. The foundation of this effort is an evolutionarily motivated definition of technology that highlights three key features: material production, social collaboration, and cultural reproduction. This broad scope respects the complexity of the subject but poses a challenge for theoretical unification. Addressing this challenge requires a comparative approach to reduce the diversity of real-world technological cognition to a smaller number of recurring processes and relationships. To this end, a synthetic perceptual-motor hypothesis (PMH) for the evolutionary-developmental-cultural construction of technological cognition is advanced as an initial target for investigation.

Causal Reasoning and Event Cognition as Evolutionary Determinants of Language Structure

The aim of this article is to provide an evolutionarily grounded explanation of central aspects of the structure of language. It begins with an account of the evolution of human causal reasoning. A comparison between humans and non-human primates suggests that human causal cognition is based on reasoning about the underlying forces that are involved in events, while other primates hardly understand external forces. This is illustrated by an analysis of the causal cognition required for early hominin tool use. Second, the thinking concerning forces in causation is used to motivate a model of human event cognition. A mental representation of an event contains two vectors representing a cause as well as a result but also entities such as agents, patients, instruments and locations. The fundamental connection between event representations and language is that declarative sentences express events (or states). The event structure also explains why sentences are constituted of noun phrases and verb phrases. Finally, the components of the event representation show up in language, where causes and effects are expressed by verbs, agents and patients by nouns (modified by adjectives), locations by prepositions, etc. Thus, the evolution of the complexity of mental event representations also provides insight into the evolution of the structure of language.

Children and innovation: play, play objects and object play in cultural evolution

Cultural evolutionary theory conceptualises culture as an information-transmission system whose dynamics take on evolutionary properties. Within this framework, however, innovation has been likened to random mutations, reducing its occurrence to chance or fortuitous transmission error. In introducing the special collection on children and innovation, we here place object play and play objects - especially functional miniatures - from carefully chosen archaeological contexts in a niche construction perspective. Given that play, including object play, is ubiquitous in human societies, we suggest that plaything construction, provisioning and use have, over evolutionary timescales, paid substantial selective dividends via ontogenetic niche modification. Combining findings from cognitive science, ethology and ethnography with insights into hominin early developmental life-history, we show how play objects and object play probably had decisive roles in the emergence of innovative capabilities. Importantly, we argue that closer attention to play objects can go some way towards addressing changes in innovation rates that occurred throughout human biocultural evolution and why innovations are observable within certain technological domains but not others.

Where does the elephant come from? The evolution of causal cognition is the key

Osiurak and Reynaud do not explain the evolutionary emergence and development of the elephant in the room, that is, technical cognition. We first argue that there is a tight correlation between the evolution of cumulative technological culture (CTC) and the evolution of reasoning about abstract forces. Second, intentional teaching plays a greater role in CTC evolution than acknowledged in the target article.

Learner-driven innovation in the stone tool technology of early Homo sapiens

Current perspectives of stone tool technology tend to emphasize homogeneity in tool forms and core reduction strategies across time and space. This homogeneity is understood to represent shared cultural traditions that are passed down through the generations. This represents a top-down perspective on how and why stone tools are manufactured that largely restricts technological agency to experts, adults and teachers. However, just as bottom-up processes driven by children and youth influence technological innovation today, they are likely to have played a role in the past. This paper considers evidence from the archaeological record of early Homo sapiens' lithic technology in Africa that may attest to our long history of bottom-up social learning processes and learner-driven innovation. This evidence includes the role of emulative social learning in generating assemblages with diverse reduction strategies, a high degree of technological fragmentation across southern Africa during some time periods, and technological convergence through the Pleistocene. Counter to some perspectives on the uniqueness of our species, our ability to learn independently, to 'break the rules' and to play, as opposed to conforming to top-down influences, may also account for our technological success.

Extended parenting and the evolution of cognition

Traditional attempts to understand the evolution of human cognition compare humans with other primates. This research showed that relative brain size covaries with cognitive skills, while adaptations that buffer the developmental and energetic costs of large brains (e.g. allomaternal care), and ecological or social benefits of cognitive abilities, are critical for their evolution. To understand the drivers of cognitive adaptations, it is profitable to consider distant lineages with convergently evolved cognitions. Here, we examine the facilitators of cognitive evolution in corvid birds, where some species display cultural learning, with an emphasis on family life. We propose that extended parenting (protracted parent-offspring association) is pivotal in the evolution of cognition: it combines critical life-history, social and ecological conditions allowing for the development and maintenance of cognitive skillsets that confer fitness benefits to individuals. This novel hypothesis complements the extended childhood idea by considering the parents' role in juvenile development. Using phylogenetic comparative analyses, we show that corvids have larger body sizes, longer development times, extended parenting and larger relative brain sizes than other passerines. Case studies from two corvid species with different ecologies and social systems highlight the critical role of life-history features on juveniles' cognitive development: extended parenting provides a safe haven, access to tolerant role models, reliable learning opportunities and food, resulting in higher survival. The benefits of extended juvenile learning periods, over evolutionary time, lead to selection for expanded cognitive skillsets. Similarly, in our ancestors, cooperative breeding and increased group sizes facilitated learning and teaching. Our analyses highlight the critical role of life-history, ecological and social factors that underlie both extended parenting and expanded cognitive skillsets. This article is part of the theme issue 'Life history and learning: how childhood, caregiving and old age shape cognition and culture in humans and other animals'.

Prehistoric Perspectives on "Others" and "Strangers"

Social "connectivity" through time is currently considered as one of the major drivers of cultural transmission and cultural evolution. Within this framework, the interactions within and between groups are impacted by individuals' distinction of social relationships. In this paper, we focus on changes in a major aspect of social perceptions, "other" and "stranger." As inferred from the archaeological record, this perception among human groups gained importance during the course of the Pleistocene. These changes would have occurred due to the plasticity of cognitive mechanisms, in response to the demands on behavior along the trajectory of human social evolution. The concepts of "other" and "stranger" have received little attention in the archaeological discourse, yet they are fundamental in the perception of social standing. The property of being an "other" is defined by one's perception and is inherent to one's view of the world around oneself; when shared by a group it becomes a social cognitive construct. Allocating an individual the status of a "stranger" is a socially-defined state that is potentially transient. We hypothesize that, while possibly entrenched in deep evolutionary origins, the latter is a relatively late addition to socio-cognitive categorization, associated with increased sedentism, larger groups and reduced territorial extent as part of the process of Neolithization. We posit that "others" and "strangers" can be approached from contextual archaeological data, with inferences as regards the evolution of cognitive social categories. Our analysis focused on raw material studies, observations on style, and evidence for craft specialization. We find that contrary to the null hypothesis the archaeological record implies earlier emergence of complex socio-cognitive categorization. The cognitive, cultural and social processes involved in the maintenance and distinction between "others" and "strangers" can be defined as "self-domestication" that is still an on-going process.

Assessor teaching and the development of the capacity to innovate and to imitate

Human beings have generated a system of cumulative cultural learning with great adaptive value. The evolution of this system required an increase in the capacity to innovate and to imitate in hominin lineage. However that development is costly and, moreover, imitation may restrain the adaptive advantage of a greater investment on innovation. We suggest that a possible way to overcome this problem in hominin evolution was parental teaching by evaluative feedback - i.e. assessor teaching. To explore this hypothesis we developed a mathematical model of cumulative cultural learning. We consider two cognitive levels, one Basic, with less ability to imitate and innovate, and the other Smart, with more ability of both. We study the transition from Basic to Smart in the absence or in presence of teaching. We also study the transition from no teaching to teaching at each cognitive level. We show that the transition to a Smart is easier in a teaching context than in one of only imitation. We also show that the transition to teaching is easier the greater the cognitive level.

Understanding stone tool-making skill acquisition: Experimental methods and evolutionary implications

Despite its theoretical importance, the process of stone tool-making skill acquisition remains understudied and poorly understood. The challenges and costs of skill learning constitute an oft-neglected factor in the evaluation of alternative adaptive strategies and a potential source of bias in cultural transmission. Similarly, theory and data indicate that the most salient neural and cognitive demands of stone tool-making should occur during learning rather than expert performance. Unfortunately, the behavioral complexity and extensive learning requirements that make stone knapping skill acquisition an interesting object of study are the very features that make it so challenging to investigate experimentally. Here we present results from a multidisciplinary study of Late Acheulean handaxe-making skill acquisition involving twenty-six naïve participants and up to 90 hours training over several months, accompanied by a battery of psychometric, behavioral, and neuroimaging assessments. In this initial report, we derive a robust quantitative skill metric for the experimental handaxes using machine learning algorithms, reconstruct a group-level learning curve, and explore sources of individual variation in learning outcomes. Results identify particular cognitive targets of selection on the efficiency or reliability of tool-making skill acquisition, quantify learning costs, highlight the likely importance of social support, motivation, persistence, and self-control in knapping skill acquisition, and illustrate methods for reliably reconstructing ancient learning processes from archaeological evidence.

Visuospatial Integration and Hand-Tool Interaction in Cognitive Archaeology

Testing cognitive hypotheses in extinct species can be challenging, but it can be done through the integration of independent sources of information (e.g., anatomy, archaeology, neurobiology, psychology), and validated with quantitative and experimental approaches. The parietal cortex has undergone changes and specializations in humans, probably in regions involved in visuospatial integration. Visual imagery and hand-eye coordination are crucial for a species with a remarkable technological and symbolic capacity. Hand-tool relationships are not only a matter of spatial planning but involve deeper cognitive levels that concern body cognition, self-awareness, and the ability to integrate tools into body schemes, extending the body's functional and structural range. Therefore, a co-evolution between body and technology is to be expected not only in terms of anatomical correspondence but also in terms of cognitive integration. In prehistory, lithic tools are crucial in the interpretation of the cognitive abilities of extinct human species. The shape of tools and the grasping patterns associated with the corresponding haptic experience can supply some basic quantitative approaches to evaluate changes in the archaeological record. At the physiological level, electrodermal activity can be used as proxy to investigate the cognitive response during haptic experiences, revealing differences between tools and between subjects. These approaches can be also useful to evaluate whether and to what extent our complex cognitive resources are based on the capacity to export and delegate functions to external technological components.

The role of play objects and object play in human cognitive evolution and innovation

In this contribution, we address a major puzzle in the evolution of human material culture: If maturing individuals just learn their parental generation's material culture, then what is the origin of key innovations as documented in the archeological record? We approach this question by coupling a life‐history model of the costs and benefits of experimentation with a niche‐construction perspective. Niche‐construction theory suggests that the behavior of organisms and their modification of the world around them have important evolutionary ramifications by altering developmental settings and selection pressures. Part of Homo sapiens' niche is the active provisioning of children with play objects — sometimes functional miniatures of adult tools — and the encouragement of object play, such as playful knapping with stones. Our model suggests that salient material culture innovation may occur or be primed in a late childhood or adolescence sweet spot when cognitive and physical abilities are sufficiently mature but before the full onset of the concerns and costs associated with reproduction. We evaluate the model against a series of archeological cases and make suggestions for future research.

Evolutionary neuroscience of cumulative culture

Culture suffuses all aspects of human life. It shapes our minds and bodies and has provided a cumulative inheritance of knowledge, skills, institutions, and artifacts that allows us to truly stand on the shoulders of giants. No other species approaches the extent, diversity, and complexity of human culture, but we remain unsure how this came to be. The very uniqueness of human culture is both a puzzle and a problem. It is puzzling as to why more species have not adopted this manifestly beneficial strategy and problematic because the comparative methods of evolutionary biology are ill suited to explain unique events. Here, we develop a more particularistic and mechanistic evolutionary neuroscience approach to cumulative culture, taking into account experimental, developmental, comparative, and archaeological evidence. This approach reconciles currently competing accounts of the origins of human culture and develops the concept of a uniquely human technological niche rooted in a shared primate heritage of visuomotor coordination and dexterous manipulation.

Demonstration and Pantomime in the Evolution of Teaching

Donald proposes that early Homo evolved mimesis as a new form of cognition. This article investigates the mimesis hypothesis in relation to the evolution of teaching. The fundamental capacities that distinguish hominin teaching from that of other animals are demonstration and pantomime. A conceptual analysis of the instructional and communicative functions of demonstration and pantomime is presented. Archaeological evidence that demonstration was used for transmitting the Oldowan technology is summarized. It is argued that pantomime develops out of demonstration so that the primary objective of pantomime is that the onlooker learns the motoric patterns shown in the pantomime. The communicative use of pantomime is judged to be secondary. This use of pantomime is also contrasted with other forms of gestures. A key feature of the analysis is that the meaning of a pantomime is characterized by the force patterns of the movements. These force patterns form the core of a model of the cognitive mechanism behind pantomime. Finally, the role of pantomime in the evolution of language is also discussed.