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

Play Behavior Varies with Age, Sex, and Socioecological Context in Wild, Immature Orangutans (Pongo spp.)

Play is thought to serve different purposes at different times during ontogeny. The nature and frequency of play are expected to change accordingly over the developmental trajectory and with socio-ecological context. Orangutans offer the opportunity to disentangle the ontogenetic trajectories of solitary and social play with their extended immature phase, and socio-ecological variation among populations and species. We evaluated the frequency of play in 39 immature individuals across two populations (Pongo pygmaeus wurmbii, at Tuanan, Borneo, and P. abelii at Suaq, Sumatra), age (0-11 years), sex, and social context, using more than 11 500 h of full-day focal observation data. We found independent age trajectories of different play types, with solitary object and solitary locomotor peaking before social play. Social play partners changed during ontogeny, and male immatures were more likely to engage in non-mother social play than females. Overall, social play was more frequent at Suaq than Tuanan, linked to the more frequent availability of partners. Furthermore, per time in association with conspecifics, Tuanan immatures were as likely to engage in social play as their peers at Suaq, suggesting similar intrinsic motivation. Increasing fruit availability correlated with both longer associations and increased social play frequency in the less sociable population of Tuanan, but not at Suaq. Our findings on orangutans support evidence from other species that different play types follow different developmental trajectories, vary with sex, social opportunities, and ecological context. Although drawing functional inferences is challenging, the distinct developmental trajectories reflecting adult sociability and behavioral repertoires may indicate that play serves several, non-mutually exclusive functions during ontogeny.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10764-023-00414-2.

Atlatl use equalizes female and male projectile weapon velocity

The atlatl is a handheld, rod-shaped device that employs leverage to launch a dart, and represents a major human technological innovation. One hypothesis for forager atlatl adoption over its presumed predecessor, the thrown javelin, is that a diverse array of people could achieve equal performance results, thereby facilitating inclusive participation of more people in hunting activities. We tested this hypothesis via a systematic assessment of 2160 weapon launch events by 108 people who used both technologies. Our results show that, unlike the javelin, the atlatl equalizes the velocity of female- and male-launched projectiles. This result indicates that a javelin to atlatl transition would have promoted a unification, rather than division, of labor. Moreover, our results suggest that female and male interments with atlatl weaponry should be interpreted similarly.

Preschool Children's Loose Parts Play and the Relationship to Cognitive Development: A Review of the Literature

Play is an integrative process, and the skills acquired in it-overcoming impulses, behavior control, exploration and discovery, problem-solving, reasoning, drawing conclusions, and attention to processes and outcomes are foundational cognitive structures that drive learning and motivation. Loose parts play is a prominent form of play that many scholars and educators explicitly endorse for cognitive development (e.g., divergent thinking, problem-solving). It is unique among play types because children can combine different play types and natural or manufactured materials in one occurrence. While educators and policymakers promote the benefits of loose parts play, no previous research has explored the direct relationship between preschool-age children's indoor loose parts play experiences and cognitive development. We address this gap by bringing together the relevant literature and synthesizing the empirical studies on common play types with loose parts, namely object and exploratory, symbolic and pretend, and constructive play. We also focus on studies that examine children's experiences through loose parts, highlighting the impact of different play types on learning through the reinforcement of cognitive skills, such as executive function, cognitive self-regulation, reasoning, and problem-solving. By examining the existing literature and synthesizing empirical evidence, we aim to deepen our understanding of the relationship between children's play with loose parts and its impact on cognitive development. Ultimately, pointing out the gaps in the literature that would add to the body of knowledge surrounding the benefits of play for cognitive development and inform educators, policymakers, and researchers about the significance of incorporating loose parts play into early childhood education.

The road to conventional tool use: Developmental changes in children's material engagement with artifacts in nursery school

The development of tool use in early childhood is a topic of continuing interest in developmental psychology. However, the lack of studies in ecological settings results in many unknowns about how children come to use artifacts according to their cultural function. We report a longitudinal study with 17 sociodemographically diverse children (8 female) attending a nursery school in Madrid (Spain) and their two adult female teachers. Using mixed-effects models and Granger causality analysis, we measured changes in the frequency and duration of children's object uses between 7 and 17 months of age and in the directional influences among pairs of behaviors performed by teachers and children. Results show a clear shift in how children use artifacts. As early as 12 months of age, the frequency of conventional uses outweighs that of all other types of object use. In addition, object uses become shorter in duration with age, irrespective of their type. Moreover, certain teachers' nonlinguistic communicative strategies (e.g., demonstrations of canonical use and placing gestures) significantly influence and promote children's conventional tool use. Findings shed light on how children become increasingly proficient in conventional tool use through interactions with artifacts and others in nursery school.

Owl-like plaques of the Copper Age and the involvement of children

In the Copper Age, slate engraved plaques were produced massively in the southwestern corner of the Iberian Peninsula. Researchers have speculated about the function of these palm-sized stone objects for more than a century, although most have favored the idea that they represented goddesses, and served ritual purposes. The plaques are engraved with different designs of varying complexity. In some of them, the ones sporting two large frontal eyes, we clearly see owls modelled after two species present in the area: the little owl (Athene noctua), and the long-eared owl (Asio otus). These two species, living in semi-open habitats, were possibly the most abundant owls around the human settlements and surrounding cultivated fields of the Chalcolithic period. People must have been aware of the owl presence and possibly interacted with them. Why owls but no other animals have been the models may relate to the fact they are the most anthropomorphic of all animals, with large frontally-placed eyes in their enormous heads. In the iconography, owls are systematically represented, even today, with their two eyes staring at the observer, as opposed to the lateral view used for any other animal. Additionally, slate is one of the commonest surface rocks in southwestern Iberia, and it provides a blank canvas for engraving lines using pointed tools made of flint, quartz or copper. The way slates exfoliate makes easy to craft owl-looking plaques. To silhouette animals other than owls in a recognizable way would request extra carving abilities and specific tools. Plaque manufacture and design were simple and did not demand high skills nor intensive labor as demonstrated in replication experiments. Owl engravings could have been executed by youngsters, as they resemble owls painted today by elementary school students. This also suggests that schematic drawings are universal and timeless. We propose that the owl-like slate plaques are the remains of a set of objects used in both playful activities and in ritual ceremonies. The actual engraving of the plaques may have been part of the game. Owlish slate plaques were often perforated twice at the top. We interpret this as insertion points for actual bird feathers added to the plaques, right at the place where tufts emerge in live owls. The frontier among play and ritual is diffuse in liminal societies and there is no contradiction in playing with animal-like toys and, at some point, using them as offerings as part of community rituals related, for instance, to the colossal megalithic tombs so characteristic of the Copper Age.

Children's Evolved Learning Abilities and Their Implications for Education

In this article, I examine children's evolved learning mechanisms that make humans the most educable of animals. These include (1) skeletal perceptual and cognitive mechanisms that get fleshed out over the course of development, mainly through play; (2) a high level of plasticity that is greatest early in life but that persists into adulthood; (3) remarkable social-learning capabilities; and (4) dispositions toward exploration and play. I next examine some evolutionary mismatches-conflicts between psychological mechanisms evolved in ancient environments and their utility in modern ones-specifically with respect to modern educational systems. I then suggest some ways educators can take advantage of children's evolved learning abilities to minimize the effects of evolutionary mismatches, including (1) following developmentally appropriate practices (which are also evolutionarily appropriate practices), (2) increasing opportunities for physical activities, (3) increasing opportunities to learn through play, and (4) taking advantage of stress-adapted children's "hidden talents." I argue that evolutionary theory informs teachers and parents about how children evolved to learn and can result in more-enlightened teaching methods that will result in a more enjoyable and successful learning experiences for children.

Robert C. Dunnell's Systematics in Prehistory at 50

2021 marked the fiftieth anniversary of the publication of Robert C. Dunnell's (1971) diminutive yet dense Systematics in Prehistory. At the height of the debate between Culture History and New Archaeology, Dunnell's work sought to address a more fundamental issue that was and still is relevant to all branches of prehistoric archaeology, and especially to the study of the Palaeolithic: systematics. Dunnell himself was notorious and controversial, however, but the importance of his work remains underappreciated. Like other precocious works of that tumultuous time Systematics in Prehistory today remains absent from most course reading lists and gathers dust on library shelves. In this contribution we argue for a greater appreciation of its as yet unfulfilled conceptual and analytical promise. In particular, we briefly chart its somewhat delayed impact via evolutionary archaeology, including how it has also influenced non-Anglophone traditions, especially in South America. The obstinate persistence of classification issues in palaeoanthropology and palaeoarchaeology, we argue, warrants a second look at Dunnell's Systematics.