The sapient paradox: can cognitive neuroscience solve it?

What makes the human mind unique? One answer would be our particular kind of culture, which might be called ‘mindsharing’ culture. Human beings are not only able to detect the existence of other minds, and to understand that those minds have beliefs, but are also able to form networks of trust built around shared intentions and beliefs. No other species does anything like this. Much current research in neuroscience is aimed at understanding the processes that contribute to our construction of culture. Recognizing the importance of integrating this work into their research, and of drawing neuroscientists into more collaboration, the McDonald Institute for Archaeological Research at the University of Cambridge initiated a conference in September 2007, devoted to the theme ‘Archaeology meets neuroscience’. A special issue of the Philosophical Transactions of the Royal Society is now devoted to the proceedings of that pioneering meeting. Although understandably selective, this volume contains a smorgasbord of current ideas and research from philosophy, psychology, anthropology and archaeology. The selection of papers is diverse and stimulating. This relatively new marriage of disciplines still lacks a unifying framework, but one must start somewhere, and no time like the present. A major link between archaeology and neuroscience is provided by cognitive science, which has a foot in both camps. Some aspects of cognition, such as literacy, mathematics and music are obviously cultural in origin. Others, such as attention, perception and action stem directly from the design of the central nervous system. These two influences, brain and culture, work together in forming human cognition, and cognitive scientists find themselves in the position of having to explain many of the higher cognitive capabilities of human beings in terms of hybrid brain-culture mechanisms. Evolutionary models are one important way of ordering the evidence on hybrid mechanisms, and epigenetic factors may prove to be paramount in this process. Human infants are socially oriented learners, and cultural influence is crucial in shaping the development of higher cognitive functions in the brain. It has become clear that no theory of human cognitive evolution—including symbolic thought and language—can succeed without accounting for the role played by culture in shaping the adult mind and brain. And no account of human cognitive and cultural evolution can attain widespread acceptance unless it is compatible with what we know of brain function. Colin Renfrew's keynote article in this volume focuses on what he calls the ‘sapient paradox’, a puzzle that has been a thorn in the side of prehistory researchers for some time. There seems to have been a long—in fact, inordinately long—delay between the emergence of anatomically modern humans and our later cultural flowering. Both genetic and archaeological evidence converge on the conclusion that the ‘speciation’ phase of sapient humans occurred in Africa at least 70 000–100 000 years BP, and possibly earlier, and all modern humans are descended from those original populations. Renfrew labels a later period, extending from 10 000 years ago to the present, as the ‘tectonic’ phase. This has been a period of greatly accelerated change, stepping relatively quickly through several different levels of social and material culture, including the domestication of plants and animals, sedentary societies, cities and advanced metallurgy. It has culminated in many recent changes, giving us dramatic innovations, such as skyscrapers, atomic energy and the internet. The paradox is that there was a gap of well over 50 000 years between the speciation and tectonic phases. The acceleration of recent cultural change is especially puzzling when viewed in the light of the hundreds of thousands of years it took our ancestors to master fire, stone tool making and coordinated seasonal hunting. If human beings were biologically modern 70 000 years ago, why the long delay before this cultural potential was realized? One might be tempted to invoke climate as an excuse. The most recent Ice Age effectively prevented the development of agriculture until about 12 000 years ago. But once nature gave us a break, so to speak, we quickly domesticated plants and animals, and moved into larger, more stable communities in regions of the planet favourable to this development. Thus, one solution to Renfrew's paradox may be that there is no paradox. Another might be that there was no delay, and that he has unfairly discounted the tremendous innovations our ancestors made during the so-called delay period, which was marked by numerous innovations in toolmaking, boat building, painting, sculpture and navigation, among other things. Whilst our ancestors did not reach the stability and prosperity of later societies, their achievements were nevertheless impressive, when contrasted to the lifestyles of previous hominids. So why place the tectonic phase so late? Why not move it back to the time when the first boats were invented, or the first caves painted? At this point, the run-up to modernity begins to look more gradual, driven by an accumulation of culturally invented cognitive tools that eventually reached a critical tipping point. Despite these valid questions, the central point of Renfrew's observation remains true. There was a dramatic acceleration in the rate of human cultural and technological change that began about 10 000 years ago, and it is important to understand how our species suddenly became so innovative. There is no evidence for a major change in the brain after speciation that might explain this. There may well have been many minor changes, but present evidence shows that the cognitive basics of human existence—imitation, language and symbolic thought—are shared by all living humans and that the basic elements of higher cognition are present in all known cultures. Renfrew thinks that the interaction between material culture and the brain accounts for a great deal about the acceleration of the cognitive-cultural evolution of humans, a position that I strongly support. Of course, the biological potential had to be there, in the form of increased brain plasticity and a capacity for learning and communication. But humanity could not have reached its present levels of cultural change without first advancing the technology of symbolic communication. Renfrew raises many questions that should concern neuroscientists. How does culture influence brain development? What are the key neural components of the human brain-culture interface, and of our social mind-set? What detailed causal chains enable the cognitive-cultural chemistry of sapient society to work? More urgently, perhaps: how might they be optimized? The rest of the papers in this volume address these questions in various ways. They can be clustered around two broad themes: material culture and distributed cognition; and underlying neural and cognitive adaptations. In his thought-provoking paper, Ed Hutchins proposes that the study of human cognition should be extended beyond the brain, into distributed networks of cultural practice, which include the cognitive use of material artefacts woven into webs of social interaction and ritual. He argues that such networks can amplify the apparent intelligence of the individual, and can make apes (and by extension, humans) seem symbolically more competent than they are. Hutchins's claim (bound to be controversial among researchers who work on primate behaviour) is that the apparent symbolic competence of enculturated apes, such as the bonobo Kanzi, might be illusory, and stems from the apes’ role as components in a distributed system of cultural practice into which they have been placed by their human keepers. This is because the framework of cultural practice, which ultimately orchestrates the apes’ performance, does not demand a fully symbolic response. The same might be said of many apparently symbolic operations carried out by humans, such as rote addition and subtraction. Hutchins implicitly defines ‘true’ symbolic processing as an internal cognitive process of ‘seeing as’, which is unique to humans. According to Hutchins, Kanzi's performances are merely chains of non-symbolic responses to specific stimuli, linked by chains of cultural practice. Of course, it might be that these apes are symbolically competent, but the research paradigm used may not enable us to make an informed choice between these interpretations. How can we choose between them, if all we have to go on is the apes’ behaviour? Hutchins's choice is based mostly on a 10-year old behavioural study, which compared ‘enculturated’ with ‘non-enculturated’ chimpanzees on a series of symbolic tasks. Both groups were trained to perceive symbols as representations of abstract relationships (such as larger or smaller, lighter or darker) and to generalize their knowledge to new tasks. The results showed that the apes’ successful use of symbols did not depend on their having been enculturated into a human-like social environment. Apes raised in a laboratory performed the tasks equally well. Hutchins points out, correctly, that the lab-raised animals used in the behavioural study were also reared in a human–ape artificial culture, with a special set of cultural practices. It may have been a different set of cultural practices from the ones used by the Rumbaughs with Kanzi, but it was nevertheless qualitatively similar. Their environments had crucial cultural practices in common, which systematically led the apes to notice and respond to certain stimulus features in the testing situation. This involved, especially, conditioning their attention; they had to learn where and when to look, and what to attend to. This enabled them to use human-made symbols to communicate, without altering their basic cognitive abilities. Culture led the way. It was a specific chain of cultural practice that led their attention from one key aspect of the world to another (this seems to be how human children learn language). Even if we concede the point, we might complain that this article still begs the question of whether apes are ‘real’ symbol users. Maybe symbol recognition is one thing, and symbolic invention another, in both apes and humans. Maybe apes, and early hominids, were able to perceive truly symbolic relationships in their natural environment because they responded to various cues in a passively representational manner. Maybe all that symbolic recognition normally demands of us is that we attend selectively and knowledgeably to the specific relationships the symbol is supposed to elicit. The use of symbols in this relatively passive manner does not require the perceiver to invent a representational action, and it is well established that apes are poor at this. I have postulated that symbolic invention is something else entirely, and evolved independently, along its own trajectory, in humans (Donald, 1991). Animals raised in conventional laboratories do not have anything like Kanzi's language capabilities, and the simple discrimination paradigms cited by Hutchins were not as complex as those used by Savage-Rumbaugh and her colleagues. Kanzi's abilities appear to be qualitatively more complex and abstract. Why should we refuse to call his behaviour truly symbolic? Hutchins is right in pointing out that a distributed cultural-cognitive system might account for a lot of competent symbol use without requiring any deep capacity for symbolic invention. However, our primate ancestors may well have been ‘symbol-ready’ long before we evolved the capacity to invent symbolic representations and build systems of practice based on them. They lacked the crucial ability to invent symbols themselves. Hence, they were unable to invent the mind tools needed for sharing cultural representations. This raises the question of the neural interface with symbols and tools. In their paper, Dietrich Stout and his colleagues describe several PET studies on the neural sources of stone toolmaking skills in three expert subjects (archaeologists and anthropologists experienced in making stone tools). They compared three stone-knapping conditions: a control condition, in which subjects were not trying to manufacture a tool; a second condition, where they made a primitive Oldowan stone tool; and a third, where they made a more sophisticated Acheulian handaxe. PET results were also compared with those of a previous study on untrained novices. The results showed activation in roughly the same brain areas that are normally engaged in primate praxis, with some additional involvement of human language areas. Their data showed a significant familiarity effect (as would be expected in a learned skill), and a laterality bias that favours the hypothesis that language was somehow involved in the toolmaking expertise of these subjects (not surprising, considering that they were academics). The authors infer from this that language and toolmaking must have co-evolved, but this leap of logic escapes me. In modern subjects, we might expect an esoteric skill to be associated with language. But this does not constitute evidence for language 2.6 million years ago, when the first Oldowan tools were made, or even 1.8 million years ago, when the first Acheulian tools appeared. In short, the cerebral sources of toolmaking skill in modern humans look just like those of any other visual-manual skill. This finding is interesting, but leaves the evolutionary question wide open. Scott Frey reviews several clinical cases of patients who lost skills following brain injury, and presents recent MRI evidence on human praxis, for which he used an imaginative rehearsal paradigm. Like Stout et al., he argues for a common origin for stone toolmaking and language, and concludes that gesture and toolmaking might have common origins. This is a position which I to some it is not clear how these studies to the evolutionary but the these studies can only be carried out on modern human subjects with fully modern One could not from this for that must have had language. does not their data the key to understanding toolmaking be to our knowledge about and especially about how it with the imaginative rehearsal process that human beings to their a process that I have called At the other of the Scott the issue of human cognition from the of systems which to be systems theory to account for the minds of such as human beings in their to include material culture. In this archaeological artefacts become components in a theory of This is in with own on and the importance of the interface between minds and the environment. It also with Hutchins's of networks of cultural practice. I would like to more in on both the neural and cultural He to at one this is a that was by the early and more by But may to the of basic it about such human social as theory of or What specific or ideas does systems theory to our for cognitive At this point, it is to on a he proposes to the complex process by which human capabilities are about through interaction with the material He this to one specific of material the in Age and one the which back to The manufacture of this involved the of many including and which the way in which it was to the of This is a of the way in which a material can be woven into a of cultural practice, and is a of Hutchins's many recent in the use of recent brain data to that the distributed cognitive systems of culture may have evolved through the of material representations became more internal representations in the brain became with them in new ways. The was and distributed cognitive-cultural In this article some but I would have more of the of work on symbol especially in and these areas is if we are to understand how the interface and how material culture the In is a of an important of theory and research, and an for research on the interface, and on the between the human brain and the distributed cultural-cognitive networks which it Another important theme to the human paradox is the nature of the that makes us so the unique social intelligence of human I to and the of certain major in this most from the Institute for Evolutionary which has so many important on human and social This is not to the selection of to be in this only to their from such an important meeting. are by their to out coordinated action in This a of capabilities, not one and is an to several to this by a to shared with theory with recent from and various about the human capacity for having a theory of They that coordinated action is the key to human culture, and that a theory of action must various elements to explain this This is a it a of from certain used However, on I find the a because this kind of work to that do not address basic brain mechanisms, or about culture or human prehistory in any In a volume on neuroscience and more of these would have been a new into the study of social cognition, one that is not among studies of and human but which may researchers one of the special features that makes human social cognition He between and social In humans, social groups are not qualitatively different from those in other social social groups are special to humans. It is that enculturated apes are unable to form social use of the is and has to do with It to the ability to societies, and to as of such A or a would constitute a social as a groups their ideas by sharing a which to in the This is of great it the of interaction and trust a including the of A social is to in terms of In in a or even an extended has some with most in the This is a and raises the issue of whether cognitive neuroscientists might to of social from other of one might is social cognition by the same as Hutchins's for a human imaginative capacity of ‘seeing this question He focuses on human and learning and between learning from and learning by that human may in our ability to in the which This the that are a unique of human cognition, and the that this might an kind of He a major role for based on observation in social and recent work that children can learn a of responses and behavioural by other children This and social process is extending even to the of deep However, of this and this that might be one of the key underlying the construction of culture. This is a and is compatible with evidence on the of the and regions of the in hominids. also in Like many in this that a link has been between and it has In fact, and apes, who have of are poor and even at understanding or there is no evidence that have anything to do with the social cognitive skills of A great deal of work remains to be in this and some of the that have been made on of this of may have to be once the proposes the of a of extended and a new which on of an evolutionary of his first theory of that called is special to human is that our to in terms of our with with material culture. is a of our with material culture, a process without which a could not The seems to be that many humans would not have if their in material culture did not them with the tools. This is and I he on this point. the other I with the of that is through its in material culture, and that the crucial role of artefacts should be in cognitive and also the of cognition and that humans of than abstract representations of those This claim is to own for an in ancestors over million years ago. They also and the However, the existence of on the of to the of the of I would for and more There has been based on mostly from human about directly in human and about their for the supposed of certain functions in the brain. This is by clinical However, even when we can that a specific brain is involved in a certain might be the involvement in and does not explain in any how the in that can such a And it does not us to because two paradigms might the same brain they must cognitive same might be engaged in numerous but and technology in human and it a for the of Their theory of the cognitive of human evolution on this and there is no that and a crucial role in human and the control of attention are central factors in language and tool and it is well established that functions were a major in the evolution of our form of human The major is their at a of the involved in stone toolmaking, in terms of the cognitive by this complex This is the kind of needed to design paradigms for on toolmaking, which factors so strongly in our about human cognitive these papers the of that in this and important of They also how we have in the and us how we have to before our of human cognitive and cultural evolution can be out with the kind of detailed that we all ultimately In the most is to reach on basic questions of and in this seem to have that and many of the between disciplines are are now on the of a common of There is to be and there be more and a of on this

Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.