6

Symbolic culture presupposes more than the ability to learn and transmit behavioral traditions from one generation to the next. It requires the invention of a whole new kind of things, things that have no existence in the ‘real‘ world but exist entirely in the symbolic realm.[1]

Thus, because of symbols and with the aid of symbols, Homo sapiens has been self-domesticated and adapted to a niche unlike any other that ever has existed. We have been made in the image of the word.[2]

When I teach introductory classes on biological anthropology, I spend the first day asking students to discuss what they think separates humans from the rest of the species on the planet. They propose interesting, well thought out answers, such as the use of advanced tools, speech, reason, empathy, morality, theory of mind, and religion. However, we also recognize that not all humans have speech, some lack empathy (and others argue empathy itself might be a bad thing), and many of these traits and behaviors are not seen in the youngest of humans.[3] Newborns, for example, seem to lack a theory of mind, and when exactly they learn this is debated.

For the last few years, I have had the distinct pleasure of working alongside scholars from various disciplines in an attempt to track the evolution of human wisdom and distinctiveness at the Center for Theology, Science, and Human Flourishing at the University of Notre Dame. As a trained anthropologist, I will admit that when I began my knowledge of theology was rudimentary at best. Having a liberal arts education helped, but I was fundamentally unaware of the nuanced discussions ongoing in theology that mirror what anthropologists talk about in our own field. Discussions about what makes us human can only be answered by bringing in multiple streams of evidence, scholarship, and theory. In this sense, dialogue about what makes us human must involve these transdisciplinary conversations, which keep us honest about what we can and cannot say about human behavior.

From my perspective as a scientist who studies human evolution, “what makes us human” is our shared evolutionary history. That is the one thing that every Homo sapiens in the world shares. Genes evolve too quickly for us to pinpoint a gene, or suite of genes, that make us human. The story of human evolution, however, is one we all share, going back to at least six million years ago. Viewed in this way, wisdom’s deep evolution becomes clearer; it was a fundamental part of our human past.

While wisdom is not something that most anthropologists feel comfortable talking about, our species name, Homo sapiens, reflects the deep-seated belief that wisdom is in fact what makes us human. Tellingly, when Carl Linnaeus created a place for humans in his naming system, he defined his own species not from morphological characteristics but rather by the enigmatic Latin “nosce te ipsum” (“know thyself”).[4] In later editions, Linnaeus noted that it is reason that separates humans from the other primates. It appears that we implicitly see wisdom as the characteristic that made us human, even if, as anthropologists, we are reticent to use that phrase.

In the field of anthropology, the closest scholars of human evolution get to discussing something like wisdom is the study of how our hominin ancestors became human. Based on fossil, archeological, and genetic data, many have argued that there was a time lag between when we became human skeletally and when we became human behaviorally.[5] This so-called “Sapiens Paradox”[6] has produced copious amounts of research and debate.[7] However, what is sometimes missed is the overarching assumptions of this model. It suggests that there is a clear and archeologically visible dividing line between humans who act in a modern way and those who did not. This event is seen as driving the evolutionary success of our species and is often argued to be the precipitating cause of behavioral modernity.

The evidence for this hypothesis is based upon the absence of what is termed “symbolic behavior” prior to c. 100,000 years ago. The cognitive capacities and capabilities of earlier hominins cannot be studied directly. While data from paleoneurology[8] and related studies can inform on this topic, archeological data provides the strongest bridge between behaviors in the past and the development of human cognitive capacities.[9] However, we need to be cognizant of the limitations of datasets from the archeological record, as they are biased by research agendas, geopolitical issues, and taphonomic concerns.[10] Indeed, the fact that the term “symbolic” refers to a different set of objects for different scholars shows the problematic nature of this kind of study.[11] Sally McBrearty and Alison Brooks, for example, have argued that modern human behavior is characterized by abstract thinking, planning depth, innovativeness, and symbolic behavior, the latter of which they define as “the ability to represent objects, people, and abstract concepts with arbitrary symbols, vocal or visual, and to reify such symbols in cultural practice.”[12] Yet, as Langley et al. note, symbolism is difficult to define archeologically, though it is often assumed to be manifest in the use of figurative art, pigments, ornamentation, and body modification, among others.[13] At the theoretical level, the debate comes down to what symbolic thought is and how it can be recognized archeologically.

As part of the larger project on the evolution of human wisdom, I created a database (The “WISDOM” database ) of the archeological data that potentially correlates with symbolic thought.[14] In order to understand how the human cultural niche evolved across the Pleistocene, we need a better understanding of the actual archeological data that inform this question: at present it unclear how common symbolic, or potentially symbolic, artifacts are and what their overall distributions were. Furthermore, the spatial and temporal relationships between these classes of artifacts are far from clear. It is rare to see discussions of all the archeological indicators of contemporary human behavior in a single publication, with the exception of McBrearty and Brooks’ seminal contribution.[15] Usually, in such reviews, the focus is either on a single artifact type, a specific site, an archeological culture, or a species-specific dataset .[16] This is the first open-access dataset that concentrates on the question of symbolic thought.[17]

There is a seemingly discontinuous nature to the earliest symbolic artifacts in the archeological record, suggesting that while the earliest humans (and other members of the genus Homo) may have been capable of creating such artifacts, their use and adoption was temporally and spatially limited, with flickerings of modernity preceding the full emergence and spread of these behaviors.[18] To explain this, some scholars have invoked changes in demographic patterns,[19] though others are skeptical of this approach.[20] Others model the fluctuating fitness values of engaging in such behaviors as an explanation for the seemingly sporadic appearance of such materials, making direct analogies with genetic fitness and fitness landscapes.[21]

Here, I explore how anthropologists can interrogate the question of how our species became behaviorally modern. Concentrating on the archeological evidence, I suggest that we have reached an interesting place in that the barriers to understanding the humanization of hominins come from how we approach the question in the first place, rather than simply the available data. We need to think more about how early human populations were acting, and re-acting, in response to internal and external pressures. Becoming human was a long-term process involving changes in our phenotype, genotype, behavioral repertoire, and sociocultural niche. To demonstrate, I first discuss what we mean by “symbolic” and then describe how data from Neandertals and other early populations problematize the notion that “humanness” began c. 200,000 years ago.

What Makes Something Symbolic?

The relevance of the term “symbolic,” and how it can be best applied to the paleoanthropological record, has been the topic of much theorizing.[22] Leslie White, whose theories on cultural evolution influenced a generation of anthropologists, may have been the first to discuss the relevance of symbol-making for the question of human origins. Writing in 1940, White argued that the symbol was “the basic unit of all human behavior and civilization.”[23] He asserted that humans and the apes are separated by a bright line:

There is a fundamental difference between the mind of man and the mind of non-man. This difference is one of kind, not one of degree. And the gap between the two types is of the greatest importance—at least to the science of comparative behavior. Man uses symbols; no other creature does. A creature either uses symbols or he does not; there are no intermediate stages.[24]

Many debates today are still derived from this framework.[25] White is arguing for a type of human exceptionalism that would be rejected by most modern anthropologists. However, paleoanthropologists still often assume that symbolic thought is a “you have it or you do not” trait. If there is a major gap between modern humans and earlier, non-symbolic species, an “us versus them” mentality, then these differences are facts of nature rather than aspects of historical and cultural processes.[26]

What would these behaviors look like in the Pleistocene archeological record? Discussing the South African record, Christopher Henshilwood and Benoît Dubreuil argue that the Blombos beads are symbols, since “in the archeological literature beads are indisputably regarded as symbolic artifacts and indicative of “modern” behavior.”[27] The beads are said to show the effects of the expansion of the temporoparietal areas of the brain.[28] As for their symbolic nature, the argument rests on two inferences: (1) beads are found at different levels within Blombos and (2) the mental requirements needed to be concerned with one’s appearance are the same ones necessary for symbolic meaning. Henshilwood and Dubreuil note that children tend to be unconcerned with their appearance and do not understand how the meaning of an object, symbolically speaking, depends on a collective agreement about what that object means. This behavior may be linked, in part, to neurological changes in the hominin brain. Seeing beads as evidence of symbolic thought has not gone unquestioned, with Wynn and Coolidge suggesting that perhaps they functioned as tally devices rather than symbolically-mediated signs.[29]

Terrence Deacon has had the most influence on anthropologists in terms of the emphasis on symbol-making, especially with his emphasis on Peircean semiotics.[30] Charles Sanders Peirce saw signs as composed of three related components: the sign-vehicle, the object, and the interpretant.[31] Under a Peircean system, one can examine the sign itself, how the sign is related to its object, and its interpretant. The most famous of these relationships, at least for archeologists, is between a sign-vehicle and its object, which is the source of Peirce’s Icon-Index-Symbol distinction. It is his definition—namely that a symbolic sign is one in which the ground between the object and the sign is via conventional agreement rather than through resemblance or causal relation—that archeologists tend to apply to the past.

But this distinction is difficult to apply to the remote past since we often do not know the cultural context in which these artifacts were produced.[32] One way around this is to apply another of Peirce’s trichotomies, which looks at how the sign itself functions. Peirce defined three types of sign vehicles: qualisigns, sinsigns, and legisigns. Qualisigns, like icons, are derived from qualities. What makes a qualisign confusing is that it does not signify anything except as it is embodied in an object (like the color blue, which can be embodied in a picture or piece of fabric). The second type of sign-vehicle is the sinsign, a sign which contains several qualisigns. Finally, a legisign exists when the sign-vehicle signifies based on convention. Replicas are an individual instance of a legisign, making them a special category of sinsigns with significance based both on being a replica of a legisign and on the features of their occurrence.

But do only humans make symbols? One reason for possibly removing symbolism as an indicator of modern behavior comes from studies of nonhuman primates. Psychologist William McGrew draws attention to primate behaviors, such as male chimpanzees tearing leaves to draw attention from females and hand-clasps between grooming partners, which have a high level of variation within a group.[33] McGrew has also argued that the hand-clasp could be a group identifier.[34] Interestingly, he notes that if such behaviors were noted in human groups, they would easily be interpreted as ethnic markers. Other examples include the drumming behavior of Tai chimpanzees, which is arguably a way to communicate position in the forest.[35] Primatologist Christophe Boesch has argued that one chimp in particular used this system to communicate to others that he was either changing direction or going to take a rest. Boesch suggests that such a system is “symbolic.” Similarly, Jane Goodall’s description of a rain dance and of “waterfall displays” suggests some sort of deeper meaning to these acts.[36] Yet we need to be careful. If a chimpanzee picks up a rock and carries it to a nearby tree, that behavior could make the cover of National Geographic.[37] Would a similar behavior in a monkey receive the same attention? Furthermore, we should be careful about comparing behaviors of modern chimps to those of early humans. Chimps are very good at being chimps, but not so good at being humans. And the same is true of earlier hominins. They may not have been good at being anatomically modern humans, but they excelled at their own behaviors.

Perhaps by thinking in these terms, we can avoid fetishizing the symbol as the thing that makes us human. Using the qualisign/sinsign/legisign approach allows for the identification of a purposefully created system without the assumption of a symbolic referent. For example, engraved lines are found in different instances on ostrich eggshell, ochre, bone, and stone. Early humans were embedding qualisigns in these materials. We can perhaps trace qualisigns through different media, such as noting the persistence of the # symbol in disparate archeological assemblages. Perhaps these are examples of humans copying phosphenes.[38] Under this system, most of the early examples recorded in the WISDOM database are sinsigns. They show humans interacting with the natural world and creating artifacts, but not necessarily for the consumption of others. It may have had meaning to an individual, but we cannot tell if it was part of a larger overarching system of belief. However, at sites with many engraved eggshells, we can infer, if enough information is present, that a legisign existed. In these cases, the individuals making these artifacts were involved in a larger system within which they hoped to produce some effect on their community members’ minds.

Archeology

With these caveats in mind, we can explore what the archeological record says about the origins of symbolic thought (or perhaps the formation of legisigns). For some scholars, the best currently accepted date for what has been called “modern human behavior” begins after c. 100,000 years ago.[39] Recent research has centered on ochre use, perforated marine shells, and the creation of a complex tool kit, including the origins of bone and composite tools. Thus, it is argued that modern humans, with behaviorally modern traits, did not evolve until well after Homo sapiens evolved between 300,000 and 200,000 years ago, leaving a time gap between these two events. Explaining the paradox has been a central question in evolutionary anthropology.[40]

Perhaps the best example of how the hypothesis of symbolic thought as the defining trait of humanness has been used is in the study of Neandertals. For scientists who differentiate between Neandertals and modern humans using the designations Homo neanderthalensis and Homo sapiens, the Latin names seemingly signify a difference in intelligence. The question of which fossils fit exactly into the Neandertal group is a complex assessment. A conservative approach would classify human fossils and sites from a period between 130,000 and 30,000 years ago as the time of the classic, or Würmian, Neandertals. The complexities of the Middle-to-Late Pleistocene remains in Europe may indicate that they represent more than one species. In this case, the fossils from this time period do not demonstrate genetic continuity but rather multiple migration events from different regions in small, isolated populations.[41] Yet demonstrating gene flow would be difficult for such a small sample size (the number of fossils for this time period number being less than twenty, not counting the twenty-seven from Sima de Los Huesos). The alternative hypothesis, specifically that they represent a random breeding population, has yet to be falsified.

The question of Neandertal identity often rests on the specific definition of the group. While the majority of scholars still conceive of them as separate populations (i.e., Homo neanderthalensis), both fossil and genetic data suggest a more nuanced approach. Due to the recognition of significant gene flow between the Vindija Neandertals and Homo sapiens,[42] the null hypothesis of one species may be more defensible, but it leaves open the question of when the Neandertal population first began to diversify. It is clear that neither a strict climatic nor a cladistics approach can capture the complex picture of the Neandertalization process. It is interesting to ask if one can uncover derived behaviors—that is, behaviors that are not primitive but associated with the evolution/appearance of a new species or type—in Neandertal sites that are not recorded in modern human sites. If that were the case, what would such behaviors suggest? As Neandertals are often used as an example of the “other,”[43] a group which is not quite human and thus used in juxtaposition to show what real human behavior is, identifying such behaviors could help us to better understand what is meant by modern human behavior.

While originally considered either unable to create artwork or simply to be copying modern humans without really understanding what they were doing, Neandertals are now known to have mixed together pigments and used marine shells as palettes.[44] Recent U-series dating of cave art from Spain has supported the assertion that Neandertals may have engaged in artwork. Several large red disks, painted by blowing, have been found in the Panel de las Manos in the El Castillo cave.[45] To investigate the question of Neandertal behavior, I examined reports of the non-dietary use of birds at Middle Paleolithic Neandertal sites and at Middle Stone Age (MSA) sites associated with anatomically modern humans. Later Neandertals at various sites have been shown to have used bird and raptor remains for reasons unrelated to consumption.[46] Especially interesting is the evidence of their use of feathers. Despite a detailed search, there seems to be no evidence of the behavior recorded at MSA sites in South Africa. The Chatelperronian site of Grotte du Renne has bird bones shaped with regularly spaced notches,[47] and later Aurignacian sites show the use of the radius of a griffon vulture for a flute.[48] The MSA site of Ysterfontein, South Africa, dating to between 57,000 and 46,000 years ago, has numerous bird bones, but no indication of feather removal.[49] Two bone tools made from bird bones are reported from Blombos cave.[50] While some of the avifauna at Sidubu have cut marks, none has yet been reported to show the same sort of feather removal seen at Neandertal sites.[51] One of the bone tools from Sibudu is made from a bird radius.[52]

The point is that there is a behavior unseen in earlier hominins and also not yet recorded in the MSA, but somewhat common at archeological sites associated with Neandertals. Why remove feathers, especially ones that seem to have been selected on the basis of color, if not for adornment? A review of the ethnographic literature shows that the use of feathers is widespread in modern human culture; costly to obtain, they may have been used to signal status.[53] If the situation were reversed, and the data suggested that the people at the Still Bay site were removing feathers, it is likely that this would be used as evidence supporting modern human behavior’s origins lying in Southern Africa.

What does it mean if Neandertals show signs of symbolic thought? There is no clear answer.

1. Maybe symbolism should be removed as a sign of modern human behavior.
2. Maybe both groups evolved symbolic thought independently through parallel evolution.
3. Maybe the last common ancestor of Neandertals and modern humans had symbolic thought.
4. Maybe the species designations of Neandertals and AMH are faulty, and Neandertals should be incorporated into the H. sapiens lineage.

Apart from the Neandertals, we can also look at data from the WISDOM database itself. There are few sites with reported evidence of symbolic artifacts beyond 600,000 years ago, and those that do exist are scattered widely and are not patterned. Perhaps the most interesting, and best-known, is the Makapansgat pebble. This rock resembles a human face and seems to have been brought to the cave by hominins, though it is debatable if it represents symbolic thought.[54] In a different context, Langley notes that removing and transporting materials involves transporting or reshaping the landscape.[55] Perhaps this reflects a sinsign but not a codified idea or concept. Modern people, after all, often collect rocks and shells from exotic locations. Similar issues exist with the Kozarnika engraved bone, which dates to 1.4 million years ago.[56] If legitimate, it predates the next known engraved object by ~1,000,000 years. The ochre from Bizat Ruhama dates to over 780,000 years ago, though again this has not been accepted by all scholars.[57] Recent analysis dates the site itself to c. 1,000,000 years ago, but the ochre may not have been well-analyzed.[58] Also of note is the ochre from Gadeb 8e, Ethiopia, which dates to a minimum of 750,000 years ago. In sum, these early artifacts are tantalizing, and should not be rejected outright, but require more detailed analysis. Similar issues exist with sites between 600,000 and 400,000 years ago, where we continue to see the use of ochre and begin to see signs of more complex tool production. The artifacts and sites show the beginnings of hafting technology (which may or may not require symbolic thought).[59] More relevant is the oldest preserved wooden spear, from Clacton, U.K., dating to 400,000 years ago.[60]

The material remains from between 300,000 and 399,000 years ago are particularly salient, as they mark an increase in both the types of symbolic expressions and the number of artifacts. The Schöningen spears have been well-accepted.[61] Less well studied are Acheulean-age beads from the U.K. and surrounding areas.[62] These have not been well-dated and some of the associations are unclear, though I place them here in the hopes that more research can be undertaken on these beads, which are far removed both geographically and temporally from the majority of known shell beads. The Kabwe bone tools are well accepted as tools, though the dates may be problematic.[63] Perhaps the most provocative artifact from this group comes from Java, where Joordens et al. report on an engraved shell.[64] This artifact dates to between 640,000 and 380,000 years ago and was engraved with a sharp object in a zigzag pattern. We will likely never know what this engraved clam shell meant to its maker. The salient point here is that not only are we finding engraved objects earlier than previously believed, but they are associated with non-modern humans, in this case Homo erectus. Bilzingsleben, dated to between 370,000 and 230,000 years ago, is more controversial.[65] The engraved lines on animal bones from this site have received much attention, but detailed taphonomic study has yielded differing results as to whether these markings are human-made or not. Sites between 100,000 and 199,000 years ago are more numerous. This time period is coincident with the appearance of anatomically modern humans. Here we see good evidence of shell beads, possible art, engraved objects, and ochre. Finally, sites in the group from 45,000 to 99,0000 years ago make up the majority of both sites and artifacts in the archeological record that have evidence of symbolic thought.

To my mind, the more sporadic earlier examples are glimmerings, signals for the capacity to create symbolically-mediated objects but not the wide-scale adoption of that particular behavior. It is similar to what has been referred to as recursion, which describes times when new adaptive strategies do not persist in the record.[66] In sum, the data suggest that while evidence of symbolic thought is much more common after 200,000 years ago, glimmerings of these behaviors occur earlier, with most of the major indicators of symbolic thought found at least once before 200,000 years ago. After this time period, we see evidence of regional populations and perhaps the formation of well-defined social networks. As recent skeletal evidence and genetics suggest that the origins of Homo sapiens may date to around 300,000 years ago these data might support an early genesis for our species.[67] On the other hand, the really early examples suggest a more complicated picture. The Trinil engravings, for instance, are associated with Homo erectus fossils.

Conclusion

To be clear, with some notable exceptions, archeological signs of modernity tend to postdate 300,000 years ago, at least when using a fairly strict and standard model of what “symbolic” means. If we take a broader view, using a more encompassing model of what makes us human and taking examples such as the Trinil markings as symbols, this can prove problematic since it might make early hominins seem too human. But it can also provide a way to better understand the process of human evolution. The suggestion that a single genetic change is the main cause of behavioral modernity is untenable for a number of reasons, not the least of which is that there is no gene for behavioral modernity. Even a suite of genetic changes is unable to explain the behavioral shifts behind the origins of modern human behavior, as these are the result of a complex interplay between various evolutionary forces and inheritance systems.[68] A way around this problem is to talk about sinsigns and legisigns. Until 100,000 years ago, it is difficult to see any good evidence of legisigns in the archeological record. But we see plenty of one-off sinsigns that seem to indicate a degree of symbolic thought (though once again this is difficult to prove). Perhaps the uptick in legisigns around this time is due not to the emergence of a new species but rather to interactions between human populations. Morphological traits of Middle Pleistocene hominins are consistent with hybridization between taxa.[69] Changes in demography also played a critical role in both the presence of archeological cultures and their survivorship in the fossil and archeological record.[70]

The necessarily complex answer no doubt entails not just the use of anthropological data, but the incorporation of theories and methodologies from fields such as neuroscience, information theory, semiotics, innovation theory, and genomics. Kim Sterelny’s Apprentice Theory[71] and Michael Tomasello’s Joint and Collective Intentionality[72] models can provide insight into this time period, though these models have yet to be applied directly to the question of modern human origins. An evolutionary approach to human wisdom can incorporate all these models. We tend to think of major transitions rather than slow, gradual change over time. Instead of privileging the symbolic we can emphasize the humanness of these behaviors. Human evolution is not a tree but rather a braided stream.[73] So maybe wisdom stands a chance in the anthropological literature. We can then center questions not on what these objects meant to early humans, but on how they were able to mean something, through the application of Peircean semiotics. This ability to create objects that not only have meaning, but are created with the intent to produce a specific meaning/response in the mind of another person, is a critical part of human behavior.

MARC KISSEL is a Visiting Assistant Professor in Anthropology at Appalachian State University, North Carolina. Marc received his Ph.D. and M.S. at the University of Wisconsin-Madison, and his B.A. from New York University. His research focuses on the biological and social origins of humans. He is interested in human evolution and in applying mathematical models, genetic data, and anthropology to questions about our evolutionary history. He has published on various topics such as early hominin mandibles, semiotics, and the processes by which hominins became human. He was a Postdoctoral Research Associate on the Evolution of Wisdom and Human Distinctiveness projects at the University of Notre Dame.

References

Bibliography

• Ackermann, Rebecca, Alex Mackay, and Michael Arnold. “The Hybrid Origin of ‘Modern’ Humans.” Evolutionary Biology 43 (2006): 1–11.
• Allington-Jones, Lu. “The Clacton Spear: The Last One Hundred Years.” Archaeology Journal 172 (June 2015): 1–24.
• Barham, L.S., A. Pinto Llona, and Chris B. Stringer. “Bone Tools from Broken Hill (Kabwe) Cave, Zambia, and Their Evolutionary Significance.” Before Farming 2.3 (2002): 1–12.
• Bednarik, Robert G. “The ‘Australopithecine’ Cobble from Makapansgat, South Africa.” South African Archaeological Bulletin 53 (1998): 4–8.
• ——. “Middle Pleistocene Beads and Symbolism.” Anthropos 100 (2005): 537–52.
• Bloom, Paul. Against Empathy: The Case for Rational Compassion. New York: Ecco, 2016.
• Boesch, Christophe. “Symbolic Communication in Wild Chimpanzees?v” Human Evolution 6 (1991): 81–9.
• Chase, Philip. “On Symbols and the Palaeolithic.” Current Anthropology 35.5 (1994): 627–29.
• Coolidge, Frederick L., and Thomas Wynn. “Comment on ‘The Still Bay and Howiesons Poort, 77–59 Ka: Symbolic Material Culture and the Evolution of the Mind during the African Middle Stone Age.’” Current Anthropology 52 (2011): 380–82.
• Conard, Nicholas J., et al. “Excavations at Schoningen and Paradigm Shifts in Human Evolution.” Journal of Human Evolution 89 (2015): 1–17.
• Conard, Nicholas J., Maria Malina, and Susanne C. Münzel. “New Flutes Document the Earliest Musical Tradition in Southwestern Germany.” Nature 460 (2009): 737–40.
• Davidson, Iain. “Bilzingsleben and Early Marking.” Rock Art Research 7 (1990): 52–6.
• Deacon, Terrence. “On the Human: Rethinking the Natural Selection of Human Language.” On the Human: A Project of the National Humanities Center (2010).
• ——. The Symbolic Species: The Co-Evolution of Language and the Brain. New York: W.W. Norton, 1997.
• d’Errico, Francesco. “The Invisible Frontier: A Multi-Species Model for the Origin of Behavioral Modernity.” Evolutionary Anthropology 12 (2003): 188–202.
• ——, and Christopher S. Henshilwood. “Additional Evidence for Bone Technology in the Southern African Middle Stone Age.” Journal of Human Evolution 52 (2007): 142–63.
• ——, Lucinda R. Backwell, and Lyn Wadley. “Identifying Regional Variability in Middle Stone Age Bone Technology: The Case of Sibudu Cave.” Journal of Archaeological Science 39 (2012): 2479–95.
• ——, et al. “Neanderthal Acculturation in Western Europe? A Critical Review of the Evidence and Its Interpretation.” Current Anthropology 39 (1998): 1–44.
• Finlayson, Clive, et al. “Birds of a Feather: Neanderthal Exploitation of Raptors and Corvids.” PLOS ONE 7 (2012): e45927.
• French, Jennifer. “Demography and the Palaeolithic Archaeological Record.” Journal of Archaeological Method 23 (2016): 150–99.
• Garofoli, Duilio. “Cognitive Archaeology Without Behavioral Modernity: An Eliminativist Attempt.” Quaternary International 405 (2015): 125–35.
• Goodall, Jane. The Chimpanzees of Gombe: Patterns of Behavior. Cambridge, MA: Belknap Press, 1986.
• Green, R.E., et al. “A Draft Sequence of the Neandertal Genome.” Science 328 (2010): 710–22.
• Henshilwood, Christopher S. “Fully Symbolic Sapiens Behaviour: Innovation in the Middle Stone Age at Blombos Cave, South Africa.” In Rethinking the Human Revolution: New Behavioural and Biological Perspectives on the Origins and Dispersal of Modern Humans, edited by Paul Mellars, et al., 123–32. Cambridge, UK: MacDonald Institute, 2007.
• ——. “The Still Bay and Howiesons Poort, 77–59 Ka.” Current Anthropology 52.3 (2011): 361–400.
• ——, and Benoît Dubreuil. “Reading the Artifacts: Gleaning Language Skills from the Middle Stone Age in Southern Africa.” In The Cradle of Language, edited by Rudolf Botha and Chris Knight, 41–61. Oxford: Oxford University Press, 2009.
• ——, and Curtis Marean. “The Origin of Modern Human Behavior.” Current Anthropology 44 (2003): 627–51.
• Hodgskiss, Tammy. “Cognitive Requirements for Ochre Use in the Middle Stone Age at Sibudu, South Africa.” Cambridge Archaeology Journal 24.3 (2014): 405–28.
• Hodgson, Derek. “Decoding the Blombos Engravings, Shell Beads and Diepkloof Ostrich Eggshell Patterns.” Cambridge Archaeological Journal 24 (2014): 57–69.
• Hopkinson, Terry. “‘Man the Symboller’: A Contemporary Origins Myth.” Archaeological Dialogues 20 (2013): 215–41.
• Hoquet, Thierry. “Biologization of Race and Racialization of the Human: Bernier, Buffon, Linnaeus.” In The Invention of Race: Scientific and Popular Representation, edited by Nicolas Bancel, Thomas David, and Dominic Thomas, 17–32. New York: Routledge, 2014.
• Hovers, Erella, and Anna Belfer-Cohen. “‘Now You See It, Now You Do Not’—Modern Human Behavior in the Middle Paleolithic.” In Before The Transition: Evolution and Stability in the Middle Paleolithic and Middle Stone Age, edited by Erella Hovers and Steven L. Kuhn, 295–304. New York: Springer, 2006.
• Hublin, Jean-Jacques, et al. “New Fossils from Jebel Irhoud, Morocco and the Pan-African Origin of Homo Sapiens.” Nature 546.7657 (2017): 289–92.
• Jablonka, Eva, and Marion Lamb. Evolution in Four Dimensions: Genetic, Epigenetic, Behavioral, and Symbolic Variation in the History of Life. Cambridge, MA: MIT Press, 2005.
• Jeffrey, S., et al. “The Archaeotools Project: Faceted Classification and Natural Language Processing in an Archaeological Context.” Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 367.1897 (2009): 2507–19.
• Joordens, Josephine, et al. “Homo Erectus at Trinil on Java Used Shells for Tool Production and Engraving.” Nature 518 (2014): 228–31.
• Kissel, Marc, and Agustín Fuentes. “A Database of Archeological Evidence of Representational Behavior.” Evolutionary Anthropology Issues, News, Revisions 26.4 (2017): 149–50.
• ——. “Semiosis in the Pleistocene.” Cambridge Archaeology Journal 27.3 (2017), 397–412.
• Klein, Richard G. “The Archeology of Modern Human Origins.” Evolutionary Anthropology 1 (1992): 5–14.
• ——, and Blake Edgar. The Dawn of Human Culture. New York: Wiley, 2002.
• ——, et al. “The Ysterfontein 1 Middle Stone Age Site, South Africa, and Early Human Exploitation of Coastal Resources.” Proceedings of the National Academy of Sciences 101 (2004): 5708–15.
• Kühl, Hjalmar, et al. “Chimpanzee Accumulative Stone Throwing.” Nature Scientific Reports 6 (2016): 1–8.
• Langley, Michelle C. “Storied Landscapes Makes Us (Modern) Human: Landscape Socialisation in the Palaeolithic and Consequences for the Archaeological Record.” Journal of Anthropology and Archaeology 32.4 (2013): 614–29.
• ——, Christopher Clarkson, and Sean Ulm. “Behavioural Complexity in Eurasian Neanderthal Populations: A Chronological Examination of the Archaeological Evidence.” Cambridge Archaeology Journal 18 (2008): 289–307.
• Lombard, Marlize, and Isabelle Parsons. “What Happened to the Human Mind after the Howiesons Poort?” Antiquity 85 (August 2011): 1433–43.
• Mania, Dietrich, and Ursula Mania. “The Natural and Sociocultural Environment of Homo Erectus at Bilzingsleben, Germany.” In The Hominid Individual in Context: Archaeological Investigations of Lower and Middle Palaeolithic Landscapes, Locales and Artifacts, edited by Clive Gamble and Martin Porr, 98–114. New York: Routledge, 2005.
• Marean, Curtis W. “An Evolutionary Anthropological Perspective on Modern Human Origins.” Annual Review of Anthropology 44 (2015): 533–56.
• McBrearty, Sally, and Alison Brooks. “The Revolution That Wasn’t: A New Interpretation of the Origin of Modern Human Behavior.” Journal of Human Evolution 39 (2000): 453–563.
• McGrew, William C. The Cultured Chimpanzee: Reflections on Cultural Primatology. Cambridge: Cambridge University Press, 2004.
• ——. “Pan Symbolicus: A Cultural Primatologist’s Viewpoint.” In Homo Symbolicus: The Dawn of Language, Imagination and Spirituality, edited by Christopher S. Henshilwood and Francesco d’Errico, 1–12. Amsterdam: John Benjamins, 2011.
• Mellars, Paul. “The Impossible Coincidence: A Single-Species Model for the Origins of Modern Human Behavior in Europe.” Evolutionary Anthropology 14 (2005): 12–27.
• ——. “Major Issues in the Emergence of Modern Humans.” Current Anthropology 30 (1989): 349–85.
• Morin, Eugène, and Véronique Laroulandie. “Presumed Symbolic Use of Diurnal Raptors by Neanderthals.” PLOS ONE 7 (2012): 1–5.
• Peirce, Charles. The Essential Peirce: Selected Philosophical Writings. Vol. 1, edited by E. Houser and C. Kloesel. Bloomington: Indiana University Press, 1992.
• Pike, A.W.G., et al. “U-Series Dating of Paleolithic Art in 11 Caves in Spain.” Science 336 (2012): 1409–13.
• Powell, Adam, Stephen Shennan, and Mark G. Thomas. “Late Pleistocene Demography and the Appearance of Modern Human Behavior.” Science 324.5932 (2009): 1298–1301.
• Radovčić, Davorka, Ankica Oros Sršen, Jakov Radovčić and David W. Frayer. “Evidence for Neandertal Jewelry: Modified White-Tailed Eagle Claws at Krapina.” PLoS ONE 10 (2015): e0119802.
• Renfrew, Colin. “The Sapient Behaviour Paradox: How to Test for Potential?” In Modelling the Early Human Mind, edited by Kathleen R. Gibson and Paul Mellars, 11–15. Cambridge, UK: MacDonald Institute, 1996.
• Rigaud, Solange, et al. “Critical Reassessment of Putative Acheulean Porosphaera Globularis Beads.” Journal of Archaeological Science 36.1 (2009): 25–34.
• Ronen, Avraham, et al. “The Lower Palaeolithic Site Bizat Ruhama in the Northern Negev, Israel.” Archaology Korrespondenzblatt 28 (1998): 163–73.
• ——. “The Oldest Human Groups in the Levant.” Comptes Rendus-Palevol 5.1–2 (2006): 343–51.
• Schlebusch, Carina M., et al. “Southern African Ancient Genomes Estimate Modern Human Divergence to 350,000 to 260,000 Years Ago.” Science 358 (2017): 652–55.
• Shennan, Stephen. “Demography and Cultural Innovation: A Model and Its Implications for the Emergence of Modern Human Culture.” Cambridge Archaeology Journal 11.1 (2001): 5–16.
• Sirakov, N., et al. “An Ancient Continuous Human Presence in the Balkans and the Beginnings of Human Settlement in Western Eurasia: A Lower Pleistocene Example of the Lower Palaeolithic Levels in Kozarnika Cave (North-Western Bulgaria).” Quaternary International 223 (2010): 94–106.
• Sterelny, Kim. The Evolved Apprentice. Cambridge, MA: MIT Press, 2012.
• Texier, Pierre-jean, et al. “The Context, Form and Significance of the MSA Engraved Ostrich Eggshell Collection from Diepkloof Rock Shelter, Western Cape, South Africa.” Journal of Archaeological Science 40 (2013): 3412–31.
• Trinkaus, Erik, and Pat Shipman. The Neandertals: Changing the Image of Mankind. New York: Knopf, 1992.
• Tomasello, Michael. A Natural History of Human Thinking. Cambridge, MA: Harvard University Press, 2014.
• Vaesen, Krist, et al. “Population Size Does Not Explain Past Changes in Cultural Complexity.” Proceedings of the National Academy of Sciences 113 (2016): E2241–47.
• Val, Aurore. “New Data on the Avifauna from the Middle Stone Age Layers of Sibudu Cave, South Africa: Taphonomic and Palaeoenvironmental Implications.” Quaternary International 421 (2016): 173–89.
• Vandermeersch, Bernard, and María Dolores Garralda. “Neanderthal Geographical and Chronological Variation.” In Continuity and Discontinuity in the Peopling of Europe: One Hundred Fifty Years of Neanderthal Study, edited by Silvana Condemi and Gerd-Christian Weniger, 113–25. New York: Springer, 2011.
• Warren, Kerryn. Of Mice and Hominins: Using the Craniomandibular Morphology of Hybrid Mice to Better Understand Hybrid Morphologies in the Hominin Fossil Record. Ph.D. diss., University of Cape Town, 2017.
• White, Leslie. “The Symbol: The Origin and Basis of Human Behavior.” Philosophy of Science 7 (1940): 451.
• Wilkins, Jayne. “Evidence for Early Hafted Hunting Technology.” Science 338 (2012): 942–46.
• Wurz, Sarah. “The Howiesons Poort at Klasies River: From Artefacts to Cognition.” M.A. thesis, University of Stellenbosch, 1997.
• Zilhão, João, et al. “Symbolic Use of Marine Shells and Mineral Pigments by Iberian Neandertals.” Proceedings of the National Academy of Sciences of the United States of America 107.3 (2010): 1023–28.