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Acknowledgements IE has received funding from the postdoctoral fellowship programme Beatriu de Pinós (2019 BP00247), funded by the Secretary of Universities and Research (Government of Catalonia) and by the Horizon 2020 programme of research and innovation of the European Union under the Marie Skłodowska-Curie grant agreement No. 801370. Laboratory materials for sample processing at the University of Barcelona were funded by the Ministerio de Ciencia e Innovaci on - PID 2020-119773 GB-I00. Visit to the site for sampling collection for this study was sponsored by a NRF Y-Rated Research Grant (No. 116358) to DS. PdlP was supported by a Poroulis grant through Cambridge University. PdlP thanks the action PID 2019- 1049449 GB-I00 funded by Spanish FEDER/Ministry of Science and Innovation. LB was funded by a National Geographic Explorer grant (NGS-54810R-19), DSI-NRF Centre of Excellence in Palaeosciences (Genus) grant (CEOOP 2020-1), and NRF African Origins Platform grant (No. 98824). Research by FdE is funded by the Research Council of Norway (SFF Centre for Early Sapiens Behaviour- SapienCE-project 262618), the Talents program of the University of Bordeaux (n. 191022_001), and the program “Human Past”, funded by the same university.We are grateful to Amafa for issuing us with the excavation permit (SAH 15/7645), and to SAHRA for an export permit (CaseID 15987).We thank two anonymous reviewers for their helpful comments that significantly improved the manuscript., Supplementary data to this article can be found online at https://doi.org/10.1016/j.quascirev.2022.107898., Border Cave is a well-known South African Middle and Early Later Stone Age site located in KwaZulu-Natal. The site has exceptional plant preservation, unparalleled in the African Middle Stone Age archaeological record. This study focuses on the phytolith and FTIR analysis of two Members (2 BS and 2 WA) of the under-documented post-Howiesons Poort occupations dating to ∼60 ka. These members contain complex successions of vertically overlapping, interdigitating light brown sediments, plant bedding and combustion features of various sizes. The complexity and distinctiveness of these deposits provide an excellent opportunity for the study of plant exploitation strategies and their associated human behaviour. Our taphonomic assessment inferred, through the variability of phytolith properties and minerals composing archaeological layers, that specific occupations suffered more physical weathering than others, for example in the form of trampling. The preservation of fragile and highly soluble phytoliths (eudicot leaf phytoliths) and the high frequencies of articulated phytoliths indicates that some bedding deposits experienced little disturbance after their deposition. Not all bedding layers dating to ⁓60 ka show, from a phytolith perspective, the same plant composition, which could be explained in terms of changes in human preference for the use of plants over time to construct bedding or because distinct types of living floors are represented. Finally, the systematic application of phytoliths and FTIR to the complex archaeological sequence of Border Cave confirm these analyses can be used in the future to identify bedding deposits not visible to the naked eye, and behavioural patterns obscured by diagenetic or biased processes during sampling., Programme Beatriu de Pinós (2019 BP00247), funded by the Secretary of Universities and Research (Government of Catalonia), Horizon 2020 programme of research and innovation of the European Union under the Marie Skłodowska-Curie grant agreement No. 801370, Ministerio de Ciencia e Innovación - PID 2020-119773 GB-I00, NRF Y-Rated Research Grant (No. 116358), Action PID 2019- 1049449 GB-I00 funded by Spanish FEDER/Ministry of Science and Innovation, National Geographic Explorer grant (NGS-54810R-19), DSI-NRF Centre of Excellence in Palaeosciences (Genus) grant (CEOOP 2020-1), NRF African Origins Platform grant (No. 98824), Research Council of Norway (SFF Centre for Early Sapiens Behaviour- SapienCE-project 262618), Talents program of the University of Bordeaux (n. 191022_001), Program “Human Past” University of Bordeaux, SAH 15/7645, CaseID 15987

Debates concerning social learning in the behavioral and the developmental cognitive sciences have largely ignored the literature on social influence in the affective sciences despite having arguably the same object of study. We argue that this is a mistake and that no complete model of social learning can exclude an affective aspect. In addition, we argue that including affect can advance the somewhat stagnant debates concerning the unique characteristics of social learning in humans compared to other animals. We first review the two major bodies of literature in nonhuman animals and human development, highlighting the fact that the former has adopted a behavioral approach while the latter has adopted a cognitive approach, leading to irreconcilable differences. We then introduce a novel framework, affective social learning (ASL), that studies the way we learn about value(s). We show that all three approaches are complementary and focus, respectively, on behavior toward; cognitions concerning; and feelings about objects, events, and people in our environment. All three thus contribute to an affective, behavioral, and cognitive (ABC) story of knowledge transmission: the ABC of social learning. In particular, ASL can provide the backbone of an integrative approach to social learning. We argue that this novel perspective on social learning can allow both evolutionary continuity and ontogenetic development by lowering the cognitive thresholds that appear often too complex for other species and nonverbal infants. Yet, it can also explain some of the major achievements only found in human cultures. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

The intentional communication of affective states is a central part of human sociality and cognition. Although nonhuman primates (henceforth primates) also signal intentionally, there is a perceived chasm between their intentional versus affective forms of communication. Whereas primate vocalizations and facial expressions are traditionally viewed as involuntary'read-outs' of affective states, gestures are considered as products of intentional control. However, this traditional view is increasingly contentious, given recent evidence of intentional signal production of primate vocalizations and facial expressions, as well as the general void of arousal-based explanations in gesture research. In this chapter, we challenge the perceived dichotomy between affective and intentional communication in primates and propose a dimensional approach, whereby primate signals can be both affective and intentional, regardless of signal modality (tactile, audible, visible) or component (gesture, facial expression, vocalization). We argue that a dimensional approach, which incorporates both affective and intentional components, would improve our knowledge on how affective and cognitive processes have jointly shaped the evolution of primate communication.

International audience; The role emotions play in the dynamics of cultural phenomena has long been neglected. The collection of articles recently published in Emotion Review provides an important first step into this necessary endeavor. In this commentary, we discuss this contribution by emphasizing the role epistemological parsimony should play in the future of this research agenda. The cultural behavior and emotions of chimpanzees is taken as reference.

Human joint action is inherently cooperative, manifested in the collaborative efforts of participants to minimize communicative trouble through interactive repair. Although interactive repair requires sophisticated cognitive abilities, it can be dissected into basic building blocks shared with non-human animal species. A review of the primate literature shows that interactionally contingent signal sequences are at least common among species of non-human great apes, suggesting a gradual evolution of repair. To pioneer a cross-species assessment of repair this paper aims at (i) identifying necessary precursors of human interactive repair; (ii) proposing a coding framework for its comparative study in humans and non-human species; and (iii) using this framework to analyse examples of interactions of humans (adults/children) and non-human great apes. We hope this paper will serve as a primer for cross-species comparisons of communicative breakdowns and how they are repaired.This article is part of the theme issue ‘Revisiting the human ‘interaction engine’: comparative approaches to social action coordination’.

Research in comparative cognition on allegedly uniquely human capacities considers the identification of these human capacities in other species as one of their main points of inquiry. Capacities are applied in their theoretical descriptions to promising empirical data. The conclusion then often is that even though, on a behavioural level, the human and nonhuman cases appear related, on a cognitive level there is no relation whatsoever because the underlying cognitive states diverge in quality. This result seems dissatisfying for two reasons: (1) there is ample empirical evidence that suggests the presence of the capacities in other species, and (2) the claim that the underlying states diverge often hinges on the reference to the theoretical definitions of these capacities only. This opinion piece focuses on the capacity of ostensive intentional communication to demonstrate that the original theoretical analyses often are not befitting a comparative endeavour and should therefore not be used as pivotal reference within comparative research. An outlook will be provided on more promising approaches to identifying ostensive communication, namely an interactive approach that will allow for ostension to not be perceived as a one-turn signalling behaviour, but as interactive, with the possibility of being established in a trial-and-error manner.This article is part of the theme issue ‘Revisiting the human ‘interaction engine’: comparative approaches to social action coordination’.

In 2015, which marked 35 years since Beaumont had worked at the site, we renewed excavations at Border Cave. Our primary aims were to reassess the stratigraphic context of the sedimentary and cultural sequence, gain insight into site formation processes, make a detailed study of organic remains, identify long term cultural trends, and characterize expressions of complex behaviour and innovation. This contribution serves as an update on activities conducted in 2018 and 2019 and provides an overview of our research findings to date, placing them in the broader context of the Middle Stone Age in southern Africa. New luminescence ages based on feldspar grains in the sedimentary sequence are in broad agreement with the previous chronology established for the site. Geoarchaeology and faunal taphonomy have started to elucidate site formation processes, showing that the members should not be considered as homogeneous units, and that associated formation interpretations established by Beaumont are simplifications that are not representative of the diverse site formation processes active in the shelter. This finding is supported by lithic analysis of the Member 2 WA assemblage that shows differences in technology between artefacts from the top, middle, and lower part of the same member. In addition, the lithic artefacts from the middle and lower part of Member 2 WA show continuities with the lithics from the underlying Members 3 BS and 1 RGBS, which were attributed by Beaumont to a different industry. Grass mats/bedding layers are preserved throughout the sequence, the oldest of which dates to ∼200 ka. The use of ash and leaves with insecticidal properties in the bedding construction reflects complex cognition, as does the cooking of starchy rhizomes that come from layers dated to 170 ka. In addition to a rich mammal fauna found in all of the deposits, the remains of a new individual, a 3–4-year-old child, were recovered from Member 1 BS.LR C that has an ESR date of 42.6 ka.

The intentional communication of affective states is a central part of human sociality and cognition. Although nonhuman primates (henceforth primates) also signal intentionally, there is a perceived chasm between their intentional versus affective forms of communication. Whereas primate vocalizations and facial expressions are traditionally viewed as involuntary 'read-outs' of affective states, gestures are considered as products of intentional control. However, this traditional view is increasingly contentious, given recent evidence of intentional signal production of primate vocalizations and facial expressions, as well as the general void of arousal-based explanations in gesture research. In this chapter, we challenge the perceived dichotomy between affective and intentional communication in primates and propose a dimensional approach, whereby primate signals can be both affective and intentional, regardless of signal modality (tactile, audible, visible) or component (gesture, facial expression, vocalization). We argue that a dimensional approach, which incorporates both affective and intentional components, would improve our knowledge on how affective and cognitive processes have jointly shaped the evolution of primate communication.

The presence of divergent and independent research traditions in the gestural and vocal domains of primate communication has resulted in major discrepancies in the definition and operationalization of cognitive concepts. However, in recent years, accumulating evidence from behavioural and neurobiological research has shown that both human and non-human primate communication is inherently multimodal. It is therefore timely to integrate the study of gestural and vocal communication. Herein, we review evidence demonstrating that there is no clear difference between primate gestures and vocalizations in the extent to which they show evidence for the presence of key language properties: intentionality, reference, iconicity and turn-taking. We also find high overlap in the neurobiological mechanisms producing primate gestures and vocalizations, as well as in ontogenetic flexibility. These findings confirm that human language had multimodal origins. Nonetheless, we note that in great apes, gestures seem to fulfil a carrying (i.e. predominantly informative) role in close-range communication, whereas the opposite holds for face-to-face interactions of humans. This suggests an evolutionary shift in the carrying role from the gestural to the vocal stream, and we explore this transition in the carrying modality. Finally, we suggest that future studies should focus on the links between complex communication, sociality and cooperative tendency to strengthen the study of language origins.

Debates concerning social learning in the behavioral and the developmental cognitive sciences have largely ignored the literature on social influence in the affective sciences despite having arguably the same object of study. We argue that this is a mistake and that no complete model of social learning can exclude an affective aspect. In addition, we argue that affect can allow bridging of the debates of the unique characteristics of social learning in humans compared to other animals. We first review the two major bodies of literature in non-human animals and human development, highlighting the fact that the former has adopted a behavioral approach while the latter has adopted a cognitive approach, leading to irreconcilable differences. We then introduce a novel framework, affective social learning (ASL), that studies the way we learn about value(s). We show that all three approaches are complementary and focus, respectively, on behavior towards, cognitions concerning, and feelings about objects, events and people in our environment. All three thus contribute to an affective, behavioral and cognitive story of knowledge transmission: the ABC of social learning. In particular, ASL can provide the backbone of an integrative approach to social learning. We argue that this novel perspective on social learning can allow both evolutionary continuity and ontogenetic development by lowering the cognitive thresholds that appear often too complex for other species and non-verbal infants. Yet, it can also explain some of the major achievements only found in human cultures.

Early plant use is seldom described in the archaeological record because of poor preservation. We report the discovery of grass bedding used to create comfortable areas for sleeping and working by people who lived in Border Cave at least 200,000 years ago. Sheaves of grass belonging to the broad-leafed Panicoideae subfamily were placed near the back of the cave on ash layers that were often remnants of bedding burned for site maintenance. This strategy is one forerunner of more-complex behavior that is archaeologically discernible from ~100,000 years ago.

Middle Stone Age cooking Early evidence of cooked starchy plant food is sparse, yet the consumption of starchy roots is likely to have been a key innovation in the human diet. Wadley et al. report the identification of whole, charred rhizomes of plants of the genus Hypoxis from Border Cave, South Africa, dated up to 170,000 years ago. These archaeobotanical remains represent the earliest direct evidence for the cooking of underground storage organs. The edible Hypoxis rhizomes appear to have been cooked and consumed in the cave by the Middle Stone Age humans at the site. Hypoxis has a wide geographical distribution, suggesting that the rhizomes could have been a ready and reliable carbohydrate source for Homo sapiens in Africa, perhaps facilitating the mobility of human populations. Science , this issue p. 87

Extraordinary preservation of plant remains provides an insight into the construction and materials of bedding at Border Cave, South Africa. Towards the back of the cave there are particularly thick layers of desiccated and charred grass and our botanical study is from bulk samples of these approximately 60,000 to 40,000 year-old layers (Members 3 BS, 2 WA, 2 BS and 1 BS Lower C). More than one type of panicoid grass was identified, sedge nutlets were present in the older layers and in Member 2 WA particularly, eudicotyledon leaves were preserved. Plant bedding construction may have altered slightly over time with the use of sedges decreasing in favour of grass. A small item that appears to be woven monocotyledon leaf blades was recovered from Member 1 BS Lower C (42,600 years old), potentially making it the oldest evidence of simple weaving. The bedding is generally desiccated rather than burned, and often lies on an ash base. It is possible that the site's occupants burned old bedding to provide an ash base for fresh bedding. The unique preservation of desiccated plant material from as early as 60,000 years ago may in part be due to these ashy surfaces.

International audience

Using fire experiments, we investigate claims that black organic residues on lithics found in Stone Age sites are markers for heat treatment of rocks in the embers of aboveground wood fires. We buried sedges overlain with lithics and bone to replicate plant bedding sometimes found in archaeological sites. Small fires were lit over the material buried under a mixture of coarse- and medium-grained sand. Black carbonised residues formed on several lithics that were in direct contact with buried sedges that burned below the fire. FTIR, Raman and preliminary GC–MS measurements were made on dried and burnt sedge, burnt bone, and on a prominent black residue that formed on one quartz piece that had been in contact with buried fresh sedge when it was heated. Importantly, we were able to confirm the spontaneous and accidental transfer of organic compounds to lithics buried and heated underground in the presence of plant material. This means that carbonised organic residues are not useful markers for determining whether heat treatment of rocks took place above or below ground. Our preliminary experiments imply that further work should be done to investigate the causes of the residues formed on lithics underground.

The concept of functional reference has been used to isolate potentially referential vocal signals in animal communication. However, its relatedness to the phenomenon of reference in human language has recently been brought into question. While some researchers have suggested abandoning the concept of functional reference altogether, others advocate a revision of its definition to include contextual cues that play a role in signal production and perception. Empirical and theoretical work on functional reference has also put much emphasis on how the receiver understands the referential signal. However, reference, as defined in the linguistic literature, is an action of the producer, and therefore, any definition describing reference in non-human animals must also focus on the producer. To successfully determine whether a signal is used to refer, we suggest an approach from the field of pragmatics, taking a closer look at specific situations of signal production, specifically at the factors that influence the production of a signal by an individual. We define the concept of signaller's reference to identify intentional acts of reference produced by a signaller independently of the communicative modality, and illustrate it with a case study of the hoo vocalizations produced by wild chimpanzees during travel. This novel framework introduces an intentional approach to referentiality. It may therefore permit a closer comparison of human and non-human animal referential behaviour and underlying cognitive processes, allowing us to identify what may have emerged solely in the human lineage.

New excavations at Border Cave use high-resolution techniques, including FT-IR, for sediment samples and thin sections of micromorphology blocks from stratigraphy. These show that sediments have different moisture regimes, both spatially and chronologically. The site preserves desiccated grass bedding in multiple layers and they, along with seeds, rhizomes, and charcoal, provide a profile of palaeo-vegetation through time. A bushveld vegetation community is implied before 100,000 years ago. The density of lithics varies considerably through time, with high frequencies occurring before 100,000 years ago where a putative MSA 1/Pietersburg Industry was recovered. The highest percentage frequencies of blades and blade fragments were found here. In Members 1 BS and 1 WA, called Early Later Stone Age by Beaumont, we recovered large flakes from multifacial cores. Local rhyolite was the most common rock used for making stone tools, but siliceous minerals were popular in the upper members. Fil: Backwell, Lucinda Ruth. University of the Witwatersrand; Sudáfrica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán; Argentina Fil: d'Errico, Francesco. Universite de Bordeaux; Francia. University of Bergen; Noruega Fil: Banks, William E.. Universite de Bordeaux; Francia Fil: de la Peña, Paloma. University of the Witwatersrand; Sudáfrica Fil: Sievers, Christine. University of the Witwatersrand; Sudáfrica Fil: Stratford, Dominic. University of the Witwatersrand; Sudáfrica Fil: Lennox, Sandra J.. University of the Witwatersrand; Sudáfrica Fil: Wojcieszak, Marine. University of the Witwatersrand; Sudáfrica Fil: Bordy, Emese M.. University Of Cape Town; Fil: Bradfield, Justin. University of the Witwatersrand; Sudáfrica Fil: Wadley, Lyn. University of the Witwatersrand; Sudáfrica

The sedge, Cladium mariscus, has been identified in Middle Stone Age deposits at the shelter Sibudu, South Africa, where the leaves were used as “bedding” – an informal floor covering for various activities. Cladium mariscus nutlets were recovered from layers 73 000–39 000 years old and are likely to have entered the shelter on the plants harvested for bedding. This paper explores the possibility that, in addition to the use of Cladium mariscus leaves for bedding, the nutlets were collected for food. The underground storage organs and nutlets of many sedge species are eaten by contemporary people and they are known to have been eaten in the past at other sites. Nutritional analysis of the nutlets and rhizomes of Cladium mariscus indicates their potential as a food source, notwithstanding the small size of the nutlets. Although there is no evidence for the preparation of Cladium mariscus for consumption at Sibudu, the abundant nutlets produced by the plants, their nutritional value and the ease of harvesti...

We conducted experiments to compare the micromorphological signatures of modern burnt sedge and grass bedding to laminated layers of carbonized material and phytoliths in Middle Stone Age deposits at the shelter, Sibudu. The experiments were designed to clarify the formation processes associated with the laminated layers and to investigate whether these previously identified layers of bedding were deliberately burned or not. The results indicate that the laminated layers were most likely produced by human activity related to the construction, maintenance and burning of bedding. Furthermore, our experiments demonstrate that large volumes of vegetal material could have produced the relatively thin, archaeological deposits of burnt bedding.

In southern Africa numerous Middle Stone Age (MSA) sites document important steps in technological and behavioural development leading to significant changes in the lifeways of modern humans. To assess whether these cultural changes and developments may be related to environmental changes we need to ascertain past environments. To do this we apply a new quantitative method, the GIS-based Coexistence Approach (CAGIS), on fossil plant material from the MSA site Sibudu, KwaZulu-Natal, South Africa. Previous qualitative environmental interpretations of the fossil fauna and flora of the site remain ambiguous. Because much of the material is anthropogenically introduced, it is difficult to distinguish between the effects of natural changes in the local vegetation and behavioural changes of the people that inhabited the shelter. CAGIS can be applied to such biased assemblages and seems to be an adequate method to directly quantify palaeoclimate and vegetation parameters at an archaeological site. The CAGIS analysis shows that during the Howiesons Poort (HP) Industry winters were slightly colder and drier than present, whereas during summer, temperatures and precipitation were similar to today. Post-HP winters were drier and colder than present, presumably colder than during the HP. Summer temperatures remained the same, but summer precipitation decreased from the HP to post-HP. Vegetation cover was less than today, may be even less than during the HP. The late MSA was observably warmer than the older periods, especially during winter. At the same time summer precipitation slightly increased and vegetation became more dense, but still remained generally open similar to today's anthropogenic landscape. Generally, climatic changes are most pronouncedly reflected in winter temperature parameters, especially in minimum winter temperatures, and to a lesser extent by changes in summer precipitation. The observed ecological trends seem to be affected mainly by variations through time in winter temperatures. This refinement of interpretation was not discernible using previous methods for analysing the Sibudu data.

We show that carbonized fruits and seeds recovered from Middle Stone Age deposits in rock shelters are likely to have been carbonized as part of post-depositional processes. We buried indigenous South African fruits, nuts and seeds at pre-determined depths and distances from the centers of experimental fires. The cold ashes of the hearths and the sand surrounding them were subsequently excavated, using standard archaeological techniques and dry-screening. The fruiting structures from the oxidizing part of the fire were burnt to ashes, whereas those buried in sand under anoxic conditions survived in varying forms. Those buried 5 cm below the center of the fire were carbonized; those buried 10 cm below the center of the fire were dehydrated; and those 5 cm and 10 cm below the surface at the outer edge of the fire were unaffected. Size, moisture or oil content of the original fruit or seed did not appear to influence whether or not carbonization took place. Temperatures recorded 5 cm below the experimental fires suggest that the carbonization occurred at or before a maximum temperature of 328 °C, and also at lower maximum temperatures (152 °C) that were maintained for long periods. Even when the quantities of a particular wood are controlled, open fires may produce variable underground temperatures and the temperatures below ancient hearths would have been equally variable. We suggest that Cyperaceae (sedge) nutlets, the most numerous fruiting structures in the Sibudu Middle Stone Age archaeobotanical assemblage, occur in the shelter as a result of human activity, subsequent burial, and accidental carbonization when hearths were built directly above the buried nutlets.

International audience; Here we provide a multiproxy record of climate change and human occupation at Wonderkrater, a spring and peat mound site situated in the interior of southern Africa. Recently extracted sediment cores yielded a number of Middle Stone Age (MSA) artefacts, prompting exploratory excavation of the sediments to understand better the geomorphology of the site, age of the sediments, cultural lithic sequence, vegetation and faunal remains, and to try to establish whether human use of the site was to some extent climatically driven. Excavations yielded late Pleistocene mammal fauna and flora, and three small MSA lithic assemblages with age estimates of 30 ka, >45 ka and 138.01 ± 7.7 ka. The upper layers comprise peat that preserves macrobotanical and faunal remains, implying local fen conditions in Acacia savanna woodland at 12 ka. Below the upper peat layers, a 1 m-thick layer of white sand yielded two MSA lithic assemblages in association with faunal remains dated to between 30.8 ± 0.7 ka and >45 ka. Clay underlying the sand has an OSL age of 63.1 ± 5.8 ka, and sandy peat below it has an Infrared Stimulated Luminescence (IRSL) age of 70 ± 10 ka. Faunal remains in the lower sand levels, and dental stable carbon isotope analysis of herbivores, indicate a substantial grassland component in the landscape during late MIS 3 (>45 ka). Charcoal, phytolith and pollen data show a change from moderately warm and dry grassy savanna woodland in the lower sand levels, to cooler and wetter grassland with woody shrubs in the uppermost levels by 30 ka. The conditions that resulted in the deposition of the sand also attracted people to the site, but whether it served as an oasis in an arid landscape, or was occupied during wet phases, is unclear. The composition of the lithic assemblages, which include many tools suitable for cutting, suggest that the peat mound may have been used as a place to harvest reeds, process plant materials and butcher animals that were either deliberately or accidentally trapped in mud or peat.

The Middle Stone Age (MSA) is associated with early behavioral innovations, expansions of modern humans within and out of Africa, and occasional population bottlenecks. Several innovations in the MSA are seen in an archaeological sequence in the rock shelter Sibudu (South Africa). At ~77,000 years ago, people constructed plant bedding from sedges and other monocotyledons topped with aromatic leaves containing insecticidal and larvicidal chemicals. Beginning at ~73,000 years ago, bedding was burned, presumably for site maintenance. By ~58,000 years ago, bedding construction, burning, and other forms of site use and maintenance intensified, suggesting that settlement strategies changed. Behavioral differences between ~77,000 and 58,000 years ago may coincide with population fluctuations in Africa.