This article reconsiders the early hominid ‘‘lithic niche’’ by examining the social implications of stone artifact making. I reject the idea that making tools for use is an adequate explanation of the elaborate artifact forms of the Lower Palaeolithic, or a sufficient cause for long-term trends in hominid technology. I then advance an alternative mechanism founded on the claim that competency in making stone artifacts requires extended learning, and that excellence in artifact making is attained only by highly skilled individuals (...) who have been taught and practiced for extensive periods. Consequently both competency and expertise in knapping comes at a high learning cost for both the individual learner and the social group to which they belong. Those high intrinsic costs of learning created contexts in which groups selected cost-reducing forms of social learning and teaching, and in which specialization could develop. Artifacts and their manufacturing processes probably acquired functions as social signals—as honest signals of valuable capacities. The magnification of these signals, through competition between knappers and through inspiring later craftspeople, may account for a substantial amount of the accumulated elaboration visible in the archaeological record. Consequently lithic artifacts operated as material symbols from an early time in hominid evolution. (shrink)

Ornaments are the most common and ubiquitous art form of the Late Pleistocene. This fact suggests a common, fundamental function somewhat different to other kinds of Paleolithic art. While the capacity for artistic expression could be considerably older than the record of preserved art would suggest, beads signal a novel development in the efficiency and flexibility of visual communication technology. The Upper Paleolithic was a period of considerable regional differentiation in material culture, yet there is remarkable consistency in the dominant (...) shapes and sizes of Paleolithic beads over more than 25,000 years and across vast areas, even though they were made from diverse materials and, in the case of mollusc shells, diverse taxonomic families. Cultural and linguistic continuity cannot explain the meta-pattern. The evidence indicates that widespread adoption of beads of redundant form was not only about local and subregional communication of personal identity or group affinity, but also an expansion in the geographic scale of social networks. The conformity of the beads grew spontaneously and in a self-organizing manner from individuals’ interest in tapping into the network as a means for spreading social and environmental risk. (shrink)

Only our lineage has ever used trackways reading to find unseen and unheard targets. All other terrestrial animals, including our great ape cousins, use scent trails and airborne odors. Because trackways as natural signs have very different properties, they possess an information-rich narrative structure. There is good evidence we began to exploit conspecific trackways in our deep past, at first purely associatively, for safety and orienteering when foraging in vast featureless wetlands. Since our own old trackways were recognizable they were (...) self-mirroring, triggering memories of what we had been up to in the past. Using them to find our way back to the band when temporarily lost or to re-find a resource-rich area discovered the day before enabled optimal foraging. Selection for daily reiteration of one’s own old trackways therefore triggered the evolution of what is distinctive about human cognition: the autobiographical or narrative (episodic) faculty for imaginative self-projection. This faculty enabled us to glean useful social information from the stories “told” by other band members’ old trackways, and created spin-off capacities for fast-track social learning. Resultant increases in socioecological complexity then created positive selective feedback loops for further entrenchment. Incrementally we became the ultra-social narrative-minded ape, capable of creating cumulative culture. (shrink)

Within paleoanthropology, the origin of behavioral modernity is a famous problem. Very large-brained hominins have lived for around half a million years, yet social lives resembling those known from the ethnographic record appeared perhaps 100,000 years ago. Why did it take 400,000 years for humans to start acting like humans? In this article, I argue that part of the solution is a transition in the economic foundations of cooperation from a relatively undemanding form, to one that imposed much more stress (...) on human motivational and cognitive mechanisms. The rich normative, ceremonial, and ideological lives of humans are a response to this economic revolution in forager lives; from one depending on immediate return mutualism to one depending on delayed and third-party reciprocation. (shrink)

Beads and other ‘body ornaments’ are very widespread components of the archaeological record of early modern humans (Homo sapiens). They appear first in the Middle Stone Age in Africa, and somewhat later in the Early Upper Paleolithic of Eurasia. The manufacture and use of ornaments is widely considered to be evidence for significant developments in human cognition. In our view, the appearance of these objects represents the interaction of evolved cognitive capacities with changing social and demographic conditions. Body ornamentation is (...) a medium or technology for communication, particularly of socially-relevant information. The widespread adoption of beads and other discrete objects as media for communication implies changes in the complexity and stability of social messages, as well as the scale of social networks. The relatively sudden appearance of beads in the Paleolithic archaeological record coincides with genetic and archaeological evidence for expansion of human populations. We argue that these changes reflect expanding scales of social interaction and more complex social landscapes resulting from unprecedentedly large and internally differentiated human populations. (shrink)

Research in archaeology and anthropology on the evolution of modern patterns of human behavior often makes use of general theories of signs, usually derived from semiotics. Recent work generalizing David Lewis’ 1969 model of signaling provides a better theory of signs than those currently in use. This approach is based on the coevolution of behaviors of sign production and sign interpretation. I discuss these models and then look at applications to human prehistoric behavior, focusing on body ornamentation, tools, and other (...) artifacts. (shrink)

The transfer of food among group members is a ubiquitous feature of small-scale forager and forager-agricultural populations. The uniqueness of pervasive sharing among humans, especially among unrelated individuals, has led researchers to evaluate numerous hypotheses about the adaptive functions and patterns of sharing in different ecologies. This article attempts to organize available cross-cultural evidence pertaining to several contentious evolutionary models: kin selection, reciprocal altruism, tolerated scrounging, and costly signaling. Debates about the relevance of these models focus primarily on the extent (...) to which individuals exert control over the distribution of foods they acquire, and the extent to which donors receive food or other fitness-enhancing benefits in return for shares given away. Each model can explain some of the variance in sharing patterns within groups, and so generalizations that ignore or deny the importance of any one model may be misleading. Careful multivariate analyses and cross-cultural comparisons of food transfer patterns are therefore necessary tools for assessing aspects of the sexual division of labor, human life history evolution, and the evolution of the family. This article also introduces a framework for better understanding variation in sharing behavior across small-scale traditional societies. I discuss the importance of resource ecology and the degree of coordination in acquisition activities as a key feature that influences sharing behavior. (shrink)

The evolution of cognition literature is dominated by views that presume the evolution of underlying neural structures. However, recent models of cognition reemphasize the role of physiological structures, development, and external resources as important components of cognition. This article argues that these alternative models of cognition challenge our understanding of human cognitive evolution. As a case study, it focuses on rehabilitating bipedalism as a crucial moment in human evolution. The australopithecines are often seen as “merely” bipedal chimpanzees, with a similar (...) suite of behaviors. But an embodied, developmental approach to understanding australopithecine cognitive abilities shows that the transition between australopithecines and the emergence of the Homo genus is less of a break than is often thought. Bipedalism on this view is not just a physiological and behavioral breakthrough: it represents a major cognitive leap as well. (shrink)

The evolution of modern human life history has involved substantial changes in the overall length of the subadult period, the introduction of a novel early childhood stage, and many changes in the initiation, termination, and character of the other stages. The fossil record is explored for evidence of this evolutionary process, with a special emphasis on middle childhood, which many argue is equivalent to the juvenile stage of African apes. Although the “juvenile” and “middle childhood” stages appear to be the (...) same from a broad comparative perspective, in that they begin with the eruption of the first molar and the achievement of the majority of adult brain size and end with sexual maturity, the detailed differences in the expression of these two stages, and how they relate to the preceding and following stages, suggest that a distinction should be maintained between them to avoid blurring subtle, but important, differences. (shrink)

In the study reported here we examined the impact of population size and two proxies of risk of resource failure on the diversity and complexity of the food-getting toolkits of hunter–gatherers and small-scale food producers. We tested three hypotheses: the risk hypothesis, the population-size hypothesis, and a hypothesis derived from niche construction theory. Our analyses indicated that the toolkits of hunter–gatherers are more affected by risk than are the toolkits of food producers. They also showed that the toolkits of food (...) producers are more affected by population size than are the toolkits of hunter–gatherers. This pattern is inconsistent with the predictions of both the risk hypothesis and the population-size hypothesis. In contrast, it is consistent with the predictions of the niche construction hypothesis. Our results indicate that niche construction has affected the evolution of technology in small-scale societies and imply that niche construction must be taken into account when seeking to understand technological variation among food producers and the technological changes that occurred in association with the various transitions to farming that have occurred over the last 10,000 years. (shrink)

Between 300,000 and 250,000 years ago early humans in Africa and Eurasia began to use durable material substances and objects as media for signaling. Initially material signals were confined to ochre and other pigments, but over time objects such as beads were also added as technologies for sending messages. Changes in the types of materials used, their durability and costs, and the contexts of their disposal indicate a series of transitions in how early humans employed signaling media. Signaling theory from (...) biology suggests that shifts in technologies over the course of the Pleistocene reflect problems in coordinating action and resolving conflicts within increasingly large and internally differentiated societies. (shrink)

I discuss the role of economics in the study of social cognition. A currently popular view is that microeconomics should collapse into psychology partly because cognitive science has shown that valuation is constitutively social, whereas non-psychological economics insists that it is not. In the paper I resist this view, partly by reference to the relevant history of economic theory, and partly by reference to an alternative model of the way in which that theory complements, without reducing to, psychological accounts of (...) social cognition. (shrink)

Why and under what conditions are individuals altruistic to family and friends in their social networks? Evolutionary psychology suggests that such behaviour is primarily the product of adaptations for kin- and reciprocal altruism, dependent on the degree of genetic relatedness and exchange of benefits, respectively. For this reason, individuals are expected to be more altruistic to family members than to friends: whereas family members can be the recipients of kin and reciprocal altruism, friends can be the recipients of reciprocal altruism (...) only. However, there is a question about how the effect of kinship is implemented at the proximate psychological level. One possibility is that kinship contributes to some general measure of relationship quality (such as ‘emotional closeness’), which in turn explains altruism. Another possibility is that the effect of kinship is independent of relationship quality. The present study tests between these two possibilities. Participants (N= 111) completed a self-report questionnaire about their willingness to be altruistic, and their emotional closeness, to 12 family members and friends at different positions in their extended social networks. As expected, altruism was greater for family than friends, and greater for more central layers of the network. Crucially, the results showed that kinship made a significant unique contribution to altruism, even when controlling for the effects of emotional closeness. Thus, participants were more altruistic towards kin than would be expected if altruism was dependent on emotional closeness alone – a phenomenon we label a ‘kinship premium’. These results have implications for the ongoing debate about the extent to which kin relations and friendships are distinct kinds of social relationships, and how to measure the ‘strength of ties’ in social networks. (shrink)