Play in evolution and development

Developmental differences in children and adults' enforcement of explore versus exploit search strategies in the United States and Turkey

Across development, as children acquire a deeper understanding of their environment, they explore less and take advantage, or "exploit," what they already know. Here, we test whether children also enforce exploration-oriented search behaviors onto others. Specifically, we ask whether children are more likely to encourage a search agent to explore versus exploit their environment, and whether this pattern varies across childhood (between 3 and 6 years). We also ask whether this pattern differs between children and adults, and generalizes across two different sociocultural contexts-Turkey and the United States-that differ on dimensions that might relate to children's decisions about exploration (e.g., curiosity-focused educational practices, attitudes toward uncertainty avoidance). Participants (N = 358) watched an agent search for rewards and were asked at various points whether the agent should "stay" (exploit) in their current location, or "go" (explore) to a new location. At all points in the experiment, children enforced exploration significantly more often than adults. Early in the agent's search, children in the US enforced exploration more often than children in Turkey; later in the search, younger children (from both sociocultural contexts) were more likely to continue enforcing exploration compared to older children. These findings highlight that children are not only highly exploratory themselves, but also enforce exploration onto others-underscoring the central role that exploration plays in driving early cognitive development across diverse sociocultural contexts. RESEARCH HIGHLIGHTS: The current study examined developmental and cross-cultural differences in children and adults' enforcement of explore-exploit search strategies. Children in the US and Turkey enforced exploration more than adults, who enforced exploitation more often; results were generally consistent across cultures with small differences. Mirroring developmental changes in children's own search behavior; the tendency to enforce exploration decreased between 3- to 6-years of age. Findings underscore the central role of an "exploration mindset" in children's early decision-making-even when exploration has no direct benefits to the child themselves.

In praise of folly: flexible goals and human cognition

Humans often pursue idiosyncratic goals that appear remote from functional ends, including information gain. We suggest that this is valuable because goals (even prima facie foolish or unachievable ones) contain structured information that scaffolds thinking and planning. By evaluating hypotheses and plans with respect to their goals, humans can discover new ideas that go beyond prior knowledge and observable evidence. These hypotheses and plans can be transmitted independently of their original motivations, adapted across generations, and serve as an engine of cultural evolution. Here, we review recent empirical and computational research underlying goal generation and planning and discuss the ways that the flexibility of our motivational system supports cognitive gains for both individuals and societies.

A non-adaptationist hypothesis of play behaviour

Play is a suite of apparently non-functional, pleasurable behaviours observed in human and non-human animals. Although the phenomenon has been studied extensively, no adaptationist behavioural theory of how play evolved can be supported by the available evidence. However, the advancement of the extended evolutionary synthesis and developments in systems biology offer alternative avenues for non-adaptationist physiological hypotheses. I therefore propose a hypothesis of play, based upon a complex ACh activity that is under agential control of the organism, whereby play initiates ACh-mediated feedforward and feedback processes which act to: (i) regulate metabolic processes; (ii) form new ACh receptors via ACh mRNA activity; (iii) mediate attention, memory consolidation and learning; and (iv) mediate social behaviours, reproduction and embryonic development. However, play occurs across taxa, but does not occur across all taxonomic groups or within all species of a taxonomic group. Thus, to support the validity of the proposed hypothesis, I further propose potential explanations for this anomaly, which include sampling and observer biases, altricial versus precocial juvenile development, and the influence of habitat niche and environmental conditions on behaviour. The proposed hypothesis thus offers new avenues for study in both the biological and social sciences, in addition to having potential applications in applied sciences, such as animal welfare and biomedical research. Crucially, it is hoped that this hypothesis will promote further study of a valid and behaviourally significant, yet currently enigmatic, biological phenomenon.

Benefit of Cognitive Environmental Enrichments on Social Tolerance and Play Behavior in Bottlenose Dolphins (Tursiops Truncatus)

Social tolerance is an essential feature of social life that can determine the good functioning of a group of animals. Play behaviors, like social play and playing with objects, are frequently associated with positive emotional and welfare states. As a result, zoos use various strategies to promote both social tolerance and play with objects. Providing animals with cognitive environmental enrichment can be an effective tool to achieve these goals. Here we tested whether cognitive environmental enrichment can promote social tolerance and play with objects in bottlenose dolphins (Tursiops truncatus). To this end, we provided a group of five dolphins with two types of cognitive enrichment: one for individual use and one for cooperative use, both based on the rope-pulling task paradigm. Then we evaluated whether social tolerance and play with objects had increased after we provided dolphins with the two enrichments. Our results go in this direction, showing that after we provided dolphins with the enrichments, their intolerance behaviors decreased, both during feeding sessions and play sessions, while their play with objects increased. As a result, the two enrichments we used could be useful for improving dolphins' housing conditions.

Prenatal allergic inflammation in rats confers sex-specific alterations to oxytocin and vasopressin innervation in social brain regions

Prenatal exposure to inflammation via maternal infection, allergy, or autoimmunity increases one's risk for developing neurodevelopmental and psychiatric disorders. Many of these disorders are associated with altered social behavior, yet the mechanisms underlying inflammation-induced social impairment remain unknown. We previously found that a rat model of acute allergic maternal immune activation (MIA) produced deficits like those found in MIA-linked disorders, including impairments in juvenile social play behavior. The neuropeptides oxytocin (OT) and arginine vasopressin (AVP) regulate social behavior, including juvenile social play, across mammalian species. OT and AVP are also implicated in neuropsychiatric disorders characterized by social impairment, making them good candidate regulators of social deficits after MIA. We profiled how acute prenatal exposure to allergic MIA changed OT and AVP innervation in several brain regions important for social behavior in juvenile male and female rat offspring. We also assessed whether MIA altered additional behavioral phenotypes related to sociality and anxiety. We found that allergic MIA increased OT and AVP fiber immunoreactivity in the medial amygdala and had sex-specific effects in the nucleus accumbens, bed nucleus of the stria terminalis, and lateral hypothalamic area. We also found that MIA reduced ultrasonic vocalizations in neonates and increased the stereotypical nature of self-grooming behavior. Overall, these findings suggest that there may be sex-specific mechanisms underlying MIA-induced behavioral impairment and underscore OT and AVP as ideal candidates for future mechanistic studies.

Information and the Umwelt: A theoretical framework for the evolution of play

Play is phylogenetically widespread, and there are many proposed theories and fitness benefits of play. However, we still need a theoretical framework that unifies our understanding of the benefits that facilitated the evolution of play in so many diverse species. Starting with von Uexküll's theory of the Umwelt (i.e., the sensory-motor worlds of animals), together with the behavior systems approach, we propose that the Umwelt is an information processing system that serves basic biological functions. During development, the Umwelt undergoes a rapid expansion in the sensory and motor stimuli it processes. We argue that play is a process that converts surplus resources into information. By increasing the information content of the developing Umwelt, play confers fitness benefits. To demonstrate that play could evolve based on its information benefits, we present a model and simulation results of the evolution of a social play learning process that provides fitness-enhancing information in adult cooperative and competitive situations. Finally, we discuss this information-theoretic framework in relation to proposed hypotheses and fitness benefits of play.

Towards a three-level neo-Tinbergenian approach to object play: Structure, causes and consequences of a behavioral puzzle

My main goal in this paper is to propose a reformulation of foundational models in behavioral research, including Tinbergen's (1963) well-known four levels of analysis (namely, ontogenetic, mechanistic, functional, and evolutionary questions) and Mayr's (1961) dichotomy between proximate and ultimate causations. After critically evaluating these influential but problematic models, I present a three-level neo-Tinbergenian approach to behavior that considers the triadic integration of behavioral causes, structure, and consequences along a single temporal continuum. I then argue that object-directed play is a good candidate behavior to apply this new paradigm by presenting significant examples of the combined analysis of at least two of these three levels. Finally, I show how stone handling, a form of culturally-transmitted object play in macaques, is perfectly amenable to this unified three-level explanatory framework. My proposed approach fits recent theoretical and empirical advances in behavioral biology, has a heuristic value, and may provide numerous benefits to a range of behavioral scientists.

Not Playing by the Rules: Exploratory Play, Rational Action, and Efficient Search

Recent studies suggest children's exploratory play is consistent with formal accounts of rational learning. Here we focus on the tension between this view and a nearly ubiquitous feature of human play: In play, people subvert normal utility functions, incurring seemingly unnecessary costs to achieve arbitrary rewards. We show that four-and-five-year-old children not only infer playful behavior from observed violations of rational action (Experiment 1), but themselves take on unnecessary costs during both retrieval (Experiment 2) and search (Experiments 3A-B) tasks, despite acting efficiently in non-playful, instrumental contexts. We discuss the value of such apparently utility-violating behavior and why it might serve learning in the long run.

The relationship between object play, language, and visual and motor skills in children at risk of developmental disorders between 12 and 37 months

BACKGROUND

Exploratory object play is a primary strategy in amassing knowledge about one's environment and determines the development of language skills at a later age. However, still much remains unknown about how object play is related to visual and language development in children at risk of developmental disorders.

PARTICIPANTS AND PROCEDURE

Forty-four children at risk of developmental disorders aged 13 to 37 months took part in the study. The measurement of object play relied on observation of children manipulating novel objects. Language skills were assessed by the Mullen Scales.

RESULTS

The results indicate that there is a correlation between specific object play behaviours, language and visual skills.

CONCLUSIONS

The findings from this study support the hypothesis that the relationship between visual and language skills and object play in children at risk of developmental disorders is different in younger and older children.

Pretend play as abstraction: Implications for early development and beyond

Humans are the only species that engages in sustained, complex pretend play. As pretend play is practically ubiquitous across cultures, it might support or afford a context for developmental advances during the juvenile period that have implications for functioning in adulthood. Early in development, learning to separate our thoughts from reality is practiced in pretend play and is associated with changes not just in cognition, but in emotional and social domains as well. Specifically, pretend play affords opportunities to engage in abstractions that could support abilities such as perspective-taking, emotion recognition and regulation, and cooperation and negotiation in childhood. In turn, the abstraction skills promoted by early pretend play might underlie creativity, innovation, and our capacity to feel empathy and moral obligation to others in later childhood and adulthood. In fact, because pretend play affords sharing our abstractions with others, it might be an early context for behaviors that ultimately promote the shared abstractions of human culture itself.

Homo sapiens and Neanderthals share high cerebral cortex integration into adulthood

There is controversy around the mechanisms that guided the change in brain shape during the evolution of modern humans. It has long been held that different cortical areas evolved independently from each other to develop their unique functional specializations. However, some recent studies suggest that high integration between different cortical areas could facilitate the emergence of equally extreme, highly specialized brain functions. Here, we analyse the evolution of brain shape in primates using three-dimensional geometric morphometrics of endocasts. We aim to determine, firstly, whether modern humans present unique developmental patterns of covariation between brain cortical areas; and secondly, whether hominins experienced unusually high rates of evolution in brain covariation as compared to other primates. On the basis of analyses including modern humans and other extant great apes at different developmental stages, we first demonstrate that, unlike our closest living relatives, Homo sapiens retain high levels of covariation between cortical areas into adulthood. Among the other great apes, high levels of covariation are only found in immature individuals. Secondly, at the macro-evolutionary level, our analysis of 400 endocasts, representing 148 extant primate species and 6 fossil hominins, shows that strong covariation between different areas of the brain in H. sapiens and Homo neanderthalensis evolved under distinctly higher evolutionary rates than in any other primate, suggesting that natural selection favoured a greatly integrated brain in both species. These results hold when extinct species are excluded and allometric effects are accounted for. Our findings demonstrate that high covariation in the brain may have played a critical role in the evolution of unique cognitive capacities and complex behaviours in both modern humans and Neanderthals.

Socioecology shapes child and adolescent time allocation in twelve hunter-gatherer and mixed-subsistence forager societies

A key issue distinguishing prominent evolutionary models of human life history is whether prolonged childhood evolved to facilitate learning in a skill- and strength-intensive foraging niche requiring high levels of cooperation. Considering the diversity of environments humans inhabit, children's activities should also reflect local social and ecological opportunities and constraints. To better understand our species' developmental plasticity, the present paper compiled a time allocation dataset for children and adolescents from twelve hunter-gatherer and mixed-subsistence forager societies (n = 690; 3-18 years; 52% girls). We investigated how environmental factors, local ecological risk, and men and women's relative energetic contributions were associated with cross-cultural variation in child and adolescent time allocation to childcare, food production, domestic work, and play. Annual precipitation, annual mean temperature, and net primary productivity were not strongly associated with child and adolescent activity budgets. Increased risk of encounters with dangerous animals and dehydration negatively predicted time allocation to childcare and domestic work, but not food production. Gender differences in child and adolescent activity budgets were stronger in societies where men made greater direct contributions to food production than women. We interpret these findings as suggesting that children and their caregivers adjust their activities to facilitate the early acquisition of knowledge which helps children safely cooperate with adults in a range of social and ecological environments. These findings compel us to consider how childhood may have also evolved to facilitate flexible participation in productive activities in early life.

Games and enculturation: A cross-cultural analysis of cooperative goal structures in Austronesian games

While most animals play, only humans play games. As animal play serves to teach offspring important life-skills in a safe scenario, human games might, in similar ways, teach important culturally relevant skills. Humans in all cultures play games; however, it is not clear whether variation in the characteristics of games across cultural groups is related to group-level attributes. Here we investigate specifically whether the cooperativeness of games covaries with socio-ecological differences across cultural groups. We hypothesize that cultural groups that engage in frequent inter-group conflict, cooperative sustenance acquisition, or that have less stratified social structures, might more frequently play cooperative games as compared to groups that do not share these characteristics. To test these hypotheses, we gathered data from the ethnographic record on 25 ethnolinguistic groups in the Austronesian language family. We show that cultural groups with higher levels of inter-group conflict and cooperative land-based hunting play cooperative games more frequently than other groups. Additionally, cultural groups with higher levels of intra-group conflict play competitive games more frequently than other groups. These findings indicate that games are not randomly distributed among cultures, but rather relate to the socio-ecological settings of the cultural groups that practice them. We argue that games serve as training grounds for group-specific norms and values and thereby have an important function in enculturation during childhood. Moreover, games might server an important role in the maintenance of cultural diversity.

Towards an expanded neuroscientific understanding of social play

Play has been recognized as a complex and diverse set of behaviors that has been difficult to define. Play can range from rough and tumble play among rats to a human child playing a computer game. Play has been understood to exist in multiple forms such as social, object, and locomotor (Burghardt, 2005). In this article we review the literatures on the neural basis of social play, on heart rate variability, on behavioral switching and set-shifting, on prepulse inhibition of the acoustic startle reflex, and on learning at the level of the basal ganglia. Each of these neuronal pathways, aside from heart rate variability, is rooted in the parafascicular nucleus of the thalamus, an important neural substrate for social play. We argue that social play optimally balances a number of opposing neural pathways by engaging systems involved in safety versus danger (heart rate variability), automatized reactions versus learned reactions to new stimuli (behavioral switching and set-shifting), and gating relevant versus less relevant stimuli (prepulse inhibition of the acoustic startle reflex). The idea that play, in addition to its role in interpersonal adaptation to social life, may have a central role in optimizing flexibility and creativity in individual response to novelty has been explored by previous authors (Huizinga, 1955; Spinka et al., 2001; Pellegrini et al., 2007; Pellis and Pellis, 2017). In this paper we explore the possible underlying neural basis for this function of play, having to do with balancing various neural networks, and in doing so propose an expanded understanding of the nature and function of social play.

Sand Play for 0-8-Year-Old Children's Health and Development: A Systematic Review Protocol

Sand play may be a significant determinant of health and development in early childhood, but systematically synthesised evidence is absent in the literature. The main objective of this study was to present a planned methodology to systematically review, and synthesise, the evidence regarding sand play and its associations with 0–8-year-old children’s health and development. The systematic review following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocols statement was registered to PROSPERO (CRD42021253852). Literature searches will be conducted using information from eight electronic databases. Studies will be included when participating children were aged 0–8 years, settings provided children with exposure to sand environments and/or materials, and child-level outcomes related to physical, cognitive, and/or social–emotional health and development. The search results will be imported to software; duplicates will be removed; and independent double screening, and study quality assessments using appropriate tools, will be conducted. Synthesis without meta-analysis will be conducted for quantitative studies similar in exposure, outcome, and content analysis to qualitative studies. Our overall confidence in each review finding will be assessed. The findings of this systematic review can inform policy makers and early childhood education teachers about the associations between sand play and children’s health and development, and its impact in practice.

Spreading the game: An experimental study on the link between children's overimitation and their adoption, transmission, and modification of conventional information

Overimitation is hypothesized to foster the spread of conventional information within populations. The current study tested this claim by assigning 5-year-old children (N = 64) to one of two study populations based on their overimitation (overimitators [OIs] vs. non-overimitators [non-OIs]). Children were presented with conventional information in the form of novel games lacking instrumental outcomes, and we observed children's adoption, transmission, and modification of this information across two study phases. Results reveal little variation across study populations in the number of game elements that were adopted and transmitted. However, OIs were more likely to use normative language than non-OIs when transmitting game information to their peers. Furthermore, non-OIs modified the games more frequently in the initial study phase, suggesting an inverse relationship between children's overimitation and their tendency to modify conventional information. These findings indicate subtle yet coherent links between children's overimitation and their tendency to transmit and modify conventional information.

Personal play identity and the fundamental elements in its development process

The aim of this study to define personal play identity and examine the fundamental elements in its development process. Within the scope of this research, 66 works (36 experimental, 28 theoretical, and two both experimental and theoretical) were reviewed and discussed by following the systematic literature review process. After reviewing process, the fundamental elements of personal play identity can be examined under four themes, namely play, personality, socio-culture and environment, and economics and technology. The evolutionary nature of play, which can be defined as an individual’s complex specialized identity is considered as a part of their development, allows personal play identity to be transferred to the next generations as it shaped by the continuous interaction of factors, such as socio-cultural environment, economy and technology. It is thought that play identity has a power that can make a positive difference to people since it presents a healthy development in most skills and attitudes which determine the quality of life, such as developing solutions for the problems faced by people throughout their lives, establishing social relations, achieving identity, and the ability to cope with problems.

Foundational Movement Skills and Play Behaviors during Recess among Preschool Children: A Compositional Analysis

This study aimed to examine the associations between play behaviors during preschool recess and foundational movement skills (FMS) in typically developing preschool children. One hundred and thirty-three children (55% male; mean age 4.7 ± 0.5 years) from twelve preschools were video-assessed for six locomotor and six object-control FMS using the Champs Motor Skill Protocol. A modified System for Observing Children's Activity and Relationships during Play assessed play behaviors during preschool recess. Associations between the composition of recess play behaviors with FMS were analyzed using compositional data analysis and linear regression. Results: Relative to time spent in other types of play behaviors, time spent in play without equipment was positively associated with total and locomotor skills, while time spent in locomotion activities was negatively associated with total and locomotor skills. No associations were found between activity level and group size play behavior compositions and FMS. The findings suggest that activity type play behaviors during recess are associated with FMS. While active games without equipment appear beneficial, preschool children may need a richer playground environment, including varied fixed and portable equipment, to augment the play-based development of FMS.

Does the Spatial Layout of a Playground Affect the Play Activities in Young Children? A Pilot Study

Background

The objective of this study was to describe, through measurement of physical activity and observation of free outdoor play, the relation between children's free play and the spatial layout of the playground. To accomplish this, we altered the spatial layout of the same playground to see how the layout affects the play activity and the physical activity levels in the same children.

Methods

Participants were six young children (four girls and two boys; mean age = 5 years and 1 month, SD = 2.59 months). Participants' physical activity level and the duration of different types of action that occurred in each area and their transitions were compared before and after the alteration of the play-equipment layout using the data from accelerometers and video recordings.

Results

A significant increase in physical activity occurred after the spatial layout alteration, which was related to action differences. Before the alteration, children tended to play in a similar manner for a given play area; however, after the alteration, pronounced interindividual variation in play activity across children was observed.

Conclusion

The present pilot study found that in free play situations in the outdoor playground, the spatial layout of playground affects the pattern of play activity and the physical activity levels of young children.

Towards a Comprehensive View of Object-Oriented Play

The exploration and/or manipulation of objects and materials, referred to as object-oriented play (OOP), is one of the most prominent activities children engage in during early childhood. Especially within early childhood education, it is important to be able to assess and understand OOP, its developmental trajectory, and developmental value. This can support early childhood educators to successfully guide or enrich children’s OOP, so it becomes a context in which learning can take place. During the past decades, three dominant theoretical perspectives have explained and assessed certain (developmental) aspects of OOP: (1) genetic epistemology, (2) cultural historical psychology, and (3) evolutionary psychology. After reviewing the literature concerning OOP according to each theoretical perspective, this paper aims to synthesize these existing theories into a unified theoretical framework. This theoretical framework can be a starting point for future research on OOP in early childhood (education). We answer the following research questions: Q1. What are the defining labels and features of the exploration and/or manipulation of objects and materials by children in early childhood?; Q2. What is the developmental trajectory of the exploration and/or manipulation of objects and materials by children in early childhood?; Q3. What is the developmental value of the exploration and/or manipulation of objects and materials by children in early childhood?

Adventurous Play as a Mechanism for Reducing Risk for Childhood Anxiety: A Conceptual Model

In this conceptual article, we draw upon the literature regarding cognitive and behavioural factors that underpin childhood anxiety to outline how a range of these risk markers might be targeted through adventurous play. When children play in an adventurous way, climbing trees, riding their bikes fast downhill and jumping from rocks, they experience feelings of fear and excitement, thrill and adrenaline. We propose that the positive, thrilling and playful emotions associated with this type of child-led play facilitate exposure to fear-provoking situations and, in doing so, provide opportunities for children to learn about physiological arousal, uncertainty and coping. We hypothesise that these learning opportunities will, over time, reduce children's risk for elevated anxiety by increasing children's expectations and ability to cope with anxiety, decreasing intolerance of uncertainty and preventing catastrophic misinterpretations of physiological arousal. If our conceptual model is correct, then ensuring that children have the physical and psychological space required to play in an adventurous way may help to decrease their risk for elevated or clinical anxiety.

Game Insight Skills as a Predictor of Talent for Youth Soccer Players

Perceptual–cognitive skills are found to be important factors for soccer players. The aim of this study was, therefore, to find within-group differences for game insight in an elite group of youth soccer players by means of a Game Insight inDicator (GID). In addition, the prospective value of perceptual–cognitive skills was examined by following the trajectory of the participants. The GID consisted of film clips that show game situations. The task of the players was to predict the trajectory and destination of the ball and move toward the correct position to receive the pass of a teammate. The film clips stopped 80 ms before, at, and 80 ms after the football contact of a teammate. We also sought to validate the GID against game performance. Participants were talented soccer players 11–13 years old and playing at the elite level for their age. Based on eight independent elite-coach judgments, two groups were created: highly talented players (HT) and less talented players (LT). The coach ratings were supported by a significant difference between the two groups based on the objective notational analysis of their game performance in 4 vs. 4 and 11 vs. 11 matches. With respect to the GID, a significant interaction effect for the groups (HT vs. LT) by occlusion time (−80, 0, and +80 ms) was found, showing that the HT performs better than the LT in 0 and +80 ms condition. In addition, GID scores were compared with soccer levels at the mean age of 19 years. Longitudinal data did not show significant differences between elite and sub-elite. Overall, the GID was found to be a valid and useful indicator for players anticipating the ball's trajectory and destination at age 11–13 years but failed to predict the players' level at age 19 years. The latter indicates how difficult it is to predict talent development.

The Paradox of Pleasurable Fear

Why do some people enjoy being afraid? A recent study by Andersen et al. found an inverted U-shaped relationship between fear and enjoyment, consistent with the theory that the pursuit of pleasurable fear is a form of play.

Learner-driven innovation in the stone tool technology of early Homo sapiens

Current perspectives of stone tool technology tend to emphasize homogeneity in tool forms and core reduction strategies across time and space. This homogeneity is understood to represent shared cultural traditions that are passed down through the generations. This represents a top-down perspective on how and why stone tools are manufactured that largely restricts technological agency to experts, adults and teachers. However, just as bottom-up processes driven by children and youth influence technological innovation today, they are likely to have played a role in the past. This paper considers evidence from the archaeological record of early Homo sapiens' lithic technology in Africa that may attest to our long history of bottom-up social learning processes and learner-driven innovation. This evidence includes the role of emulative social learning in generating assemblages with diverse reduction strategies, a high degree of technological fragmentation across southern Africa during some time periods, and technological convergence through the Pleistocene. Counter to some perspectives on the uniqueness of our species, our ability to learn independently, to 'break the rules' and to play, as opposed to conforming to top-down influences, may also account for our technological success.

The drivers and functions of rock juggling in otters

Object play refers to the seemingly non-functional manipulation of inanimate items when in a relaxed state. In juveniles, object play may help develop skills to aid survival. However, why adults show object play remains poorly understood. We studied potential drivers and functions of the well-known object play behaviour of rock juggling in Asian small-clawed (Aonyx cinereus) and smooth-coated (Lutrogale perspicillata) otters. These are closely related species, but Asian small-clawed otters perform extractive foraging movements to exploit crabs and shellfish while smooth-coated otters forage on fish. We thus predicted that frequent rock jugglers might be better at solving extractive foraging puzzles in the first species, but not the latter. We also assessed whether species, age, sex and hunger correlated with rock juggling frequency. We found that juvenile and senior otters juggled more than adults. However, rock juggling frequency did not differ between species or sexes. Otters juggled more when 'hungry', but frequent jugglers did not solve food puzzles faster. Our results suggest that rock juggling may be a misdirected behaviour when hungry and may facilitate juveniles' motor development, but it appears unrelated to foraging skills. We suggest future studies to reveal the ontogeny, evolution and welfare implications of this object play behaviour.

Preschoolers' Thoughts on the Concept of Time

This study aimed to examine preschool children's epistemological views in the context of the concept of time via their drawings of the time machine. The study was conducted with 30 five-year-old children (17 girls and 13 boys) attending state and private preschools in the academic year 2018/2019. The data collection tools used in the study were the Test for Creative Thinking - Drawing Production TCT-DP, Children's Thoughts on Time Questionnaire (CTTQ) and Children's Epistemological Views Questionnaire (CEVQ). Of the mixed methods typologies, the fully mixed sequential dominant status-qualitative design was employed. The results obtained from the study indicated that the time machine drawings of almost half the participating children included creative elements and logical thinking products. In addition, 40% of the children's responses reflected sophisticated epistemological views such as scientific, imaginative/science fiction-based, divergent and eccentric approaches and non-authority figures regarding the concept of time. In conclusion: contrary to Piegatian interpretation, our results show that five-year old children can demonstrate abstract scientific understanding regarding the concept of time and preschoolers' epistemic approach has a critical role in determining their development of abstract cognitive concepts.

The Association between the Preference for Active Play and Neurological Development in Toddlers: A Register-Based Study

Active play is regarded as physical activity during early childhood. Physical activity has many benefits for children’s physical and psychosocial health and wellbeing, as well as for their cognitive development. The aim of this study was to investigate associations between the preference for active play and neurological development in toddlers. The study was conducted as a register-based study, and the data were collected from a public-health clinic’s electronic health records. The register data about active play used in this study were originally assessed by parents at home and by early years teachers at nurseries. Neurological development was assessed by the public health nurses in public child-health clinics. The data eligible for this study were available from 717 toddlers aged 2.5–3.0 years old (mean: 2.5 years ± 2 months). The majority of toddlers (85%) showed a preference for active play, both at home and at the nursery. The prevalence of delays in the neurological development of toddlers varied in different developmental areas (by 1–15%). Delays in gross motor competence, auditory perception, and self-help skills were associated with a lower preference for active play in nursery settings, but none of the neurodevelopmental items were found to be associated with toddlers’ preference for active play at home. Nurseries need to encourage children to actively play and support their gross motor competence and self-help skills.

Gender Differences in Strategic Behavior in a Triadic Persecution Motor Game Identified Through an Observational Methodology

The main objective of the work is to address the effective behavior of girls and boys through Triadic Motor Games (TMG). A chasing game "The Maze" was applied on two class groups with a total of 42 players, 18 girls, and 24 boys, who were 12- and 13-year-old secondary school students. An observational methodology was adopted, with a nomothetic, punctual, and multidimensional design. We used a mixed registry system that two expert observers later applied through an observational methodology, obtaining sufficient record-quality levels. THEME was applied to detect temporary regularities, while cross-tabulations and growth trees were applied with the SPSS v.24 tool to reveal whether girls and boys played in similar or distinct ways. The fact that the specific decision groups within the physical education class are different for girls and boys (p < 0.005) is worth reflecting on. The game's TMG complexity was addressed through roles and subroles, giving rise to a certain motor asymmetry in relation to gender, which is an expression of behaviors lacking in playful neutrality. Through a mixed-methods approach, a study was built using observational methodology that reveals more varied motor solutions in girls, while male behavior showed greater specialization of roles and subroles, and the linkage of these solutions with the favorable modification of the marker. Identifying relevant variables when playing TMG allows a better understanding of girls and boys by analyzing their relationships, which are sometimes paradoxical, in a practical context.

Gender-Typed and Gender-Segregated Play Among Tanzanian Hadza and Congolese BaYaka Hunter-Gatherer Children and Adolescents

Few data exist on gender-typed and gender-segregated play in hunter-gatherer societies, despite their unique demographic and cultural features which may influence children's gendered play. Using naturalistic observations of Hadza (N = 46, 41% female) and BaYaka (N = 65, 48% female) hunter-gatherer 3- to 18-year-olds from Tanzania and the Republic of Congo, we showed that access to playmates was negatively associated with playing in mixed-gender groups. Young boys did not engage in more rough-and-tumble play than girls, but adolescent boys participated in this type of play more than adolescent girls. Children were also more likely to participate in work-themed play which conformed to gender norms within their society. Findings are discussed within the context of gendered division of labor, child autonomy, and demography.

Using Google Earth to Assess Shade for Sun Protection in Urban Recreation Spaces: Methods and Results

Shade in public spaces can lower the risk of and sun burning and skin cancer. However, existing methods of auditing shade require travel between sites, and sunny weather conditions. This study aimed to evaluate the feasibility of free computer software-Google Earth-for assessing shade in urban open spaces. A shade projection method was developed that uses Google Earth street view and aerial images to estimate shade at solar noon on the summer solstice, irrespective of the date of image capture. Three researchers used the method to separately estimate shade cover over pre-defined activity areas in a sample of 45 New Zealand urban open spaces, including 24 playgrounds, 12 beaches and 9 outdoor pools. Outcome measures included method accuracy (assessed by comparison with a subsample of field observations of 10 of the settings) and inter-rater reliability. Of the 164 activity areas identified in the 45 settings, most (83%) had no shade cover. The method identified most activity areas in playgrounds (85%) and beaches (93%) and was accurate for assessing shade over these areas (predictive values of 100%). Only 8% of activity areas at outdoor pools were identified, due to a lack of street view images. Reliability for shade cover estimates was excellent (intraclass correlation coefficient of 0.97, 95% CI 0.97-0.98). Google Earth appears to be a reasonably accurate and reliable and shade audit tool for playgrounds and beaches. The findings are relevant for programmes focused on supporting the development of healthy urban open spaces.

Corpse-directed play parenting by a sterile adult female chimpanzee

The study of representational play in nonhuman primates, including chimpanzees (Pan troglodytes), provides interspecific perspectives on human cognitive development and evolution. A notable form of representational play in chimpanzees is play parenting, wherein parental behavior is directed at inanimate objects. Though observed in captivity, unambiguous examples of play parenting by wild chimpanzees are rare. Here, we report two cases from Ngogo in Kibale National Park, Uganda, in which a wild adult female chimpanzee (P. t. schweinfurthii) directed parental behaviors at corpses. Both cases involved the same adult female chimpanzee, aged 20-21 years. The first case was observed on 5 March 2016, and the play object was the corpse of a bushbaby (Galago thomasi); in the second case, observed on 6 May 2017, the play object was a recently deceased chimpanzee infant postmortally stolen from the mother. The chimpanzee possessed the first and second play objects for approximately 5.5 h and 1.8 h, respectively. In both cases, she performed a variety of maternal behaviors, including co-nesting, grooming, and dorsally carrying the play objects. In contrast to previous observations of play parenting in captivity, the play parent was a presumably sterile adult female, well beyond the average age of first birth. These observations contribute to the expanding literature on chimpanzee interactions with the corpses of both conspecifics and heterospecifics.

It's the journey, not the destination: Locomotor exploration in infants

What incites infant locomotion? Recent research suggests that locomotor exploration is not primarily directed toward distant people, places, or things. However, this question has not been addressed experimentally. In the current study, we asked whether a room filled with toys designed to encourage locomotion (stroller, ball, etc.) elicits different quantities or patterns of exploration than a room with no toys. Caregivers were present but did not interact with infants. Although most walking bouts in the toy-filled room involved toys, to our surprise, 15-month-olds in both rooms produced the same quantity of locomotion. This finding suggests that mere space to move is sufficient to elicit locomotion. However, infants' patterns of locomotor exploration differed: Infants in the toy-filled room spent a smaller percent of the session within arms' reach of their caregiver and explored more locations in the room. Real-time analyses show that infants in the toy-filled room took an increasing number of steps per bout and covered more area as the session continued, whereas infants in the no-toy room took fewer and fewer steps per bout and traveled repeatedly over the same ground. Although not required to elicit locomotion, moving with toys encouraged infants to travel farther from their caregivers and to explore new areas.

The Efficiency of Infants' Exploratory Play Is Related to Longer-Term Cognitive Development

In this longitudinal study we examined the stability of exploratory play in infancy and its relation to cognitive development in early childhood. We assessed infants' (N = 130, mean age at enrollment = 12.02 months, SD = 3.5 months; range: 5-19 months) exploratory play four times over 9 months. Exploratory play was indexed by infants' attention to novelty, inductive generalizations, efficiency of exploration, face preferences, and imitative learning. We assessed cognitive development at the fourth visit for the full sample, and again at age three for a subset of the sample (n = 38). The only measure that was stable over infancy was the efficiency of exploration. Additionally, infants' efficiency score predicted vocabulary size and distinguished at-risk infants recruited from early intervention sites from those not at risk. Follow-up analyses at age three provided additional evidence for the importance of the efficiency measure: more efficient exploration was correlated with higher IQ scores. These results suggest that the efficiency of infants' exploratory play can be informative about longer-term cognitive development.

Differences in play can illuminate differences in affiliation: A comparative study on chimpanzees and gorillas

Play behaviour reinforces social affiliation in several primate species, including humans. Via a comparative approach, we tested the hypothesis that play dynamics in a group of lowland gorillas (Gorilla gorilla gorilla) are different from those in a group of chimpanzees (Pan troglodytes) as a reflection of their difference in social affiliation and agonistic support. We selected one group of lowland gorillas and one of chimpanzees, hosted at the ZooParc de Beauval (France), managed in a similar way and living in similar enclosures. The same observers video-collected and analysed data on play behaviour in both groups, by applying identical methodological procedures. Data showed that adult play was less frequent in the group of gorillas compare to chimpanzees. Polyadic play, which involves more than two players and is characterised by the most uncertain outcome, was also less frequent in gorillas than chimpanzees. Play sessions were more unbalanced (more unidirectional patterns by one of the player towards the other) in chimpanzees than in gorillas but in the latter play escalated more frequently into serious aggression. Play asymmetry in the gorilla group increased as the number of players increased, which explains why gorillas limited their polyadic playful interactions. In conclusion, our findings on the study groups of apes can be a valuable starting point to expand the study of social play in the great apes to evaluate if inter-individual affiliative relationships really account for the differences in play distribution and dynamics.

The role of play objects and object play in human cognitive evolution and innovation

In this contribution, we address a major puzzle in the evolution of human material culture: If maturing individuals just learn their parental generation's material culture, then what is the origin of key innovations as documented in the archeological record? We approach this question by coupling a life‐history model of the costs and benefits of experimentation with a niche‐construction perspective. Niche‐construction theory suggests that the behavior of organisms and their modification of the world around them have important evolutionary ramifications by altering developmental settings and selection pressures. Part of Homo sapiens' niche is the active provisioning of children with play objects — sometimes functional miniatures of adult tools — and the encouragement of object play, such as playful knapping with stones. Our model suggests that salient material culture innovation may occur or be primed in a late childhood or adolescence sweet spot when cognitive and physical abilities are sufficiently mature but before the full onset of the concerns and costs associated with reproduction. We evaluate the model against a series of archeological cases and make suggestions for future research.

THE QUALITY OF FATHER-CHILD ROUGH-AND-TUMBLE PLAY AND TODDLERS' AGGRESSIVE BEHAVIOR IN CHINA

The purpose of this study was to explore the influence of the quality of early father-child rough-and-tumble play (RTP) on toddler aggressive behaviors and more fully understand how child, mother, and father characteristics were associated with higher quality father-child RTP among contemporary urban Chinese families. Participants included 42 families in Changsha, China. Play observations of fathers and their children were coded for RTP quality. The specific RTP quality of father-child reciprocity of dominance was associated with fewer toddler aggressive behaviors, as rated by both fathers and mothers. Mothers' democratic parenting attitudes were associated with higher quality father-child RTP. These findings suggest that higher quality father-child RTP may be one way in which some fathers influence children's expression of aggressive behaviors, and the quality of father-child RTP may be influenced by the broader family, social, and cultural contexts.

The evolution of stories: from mimesis to language, from fact to fiction

Why a species as successful as Homo sapiens should spend so much time in fiction, in telling one another stories that neither side believes, at first seems an evolutionary riddle. Because of the advantages of tracking and recombining true information, capacities for event comprehension, memory, imagination, and communication evolved in a range of animal species—yet even chimpanzees cannot communicate beyond the here and now. By Homo erectus, our forebears had reached an increasing dependence on one another, not least in sharing information in mimetic, prelinguistic ways. As Daniel Dor shows, the pressure to pool ever more information, even beyond currently shared experience, led to the invention of language. Language in turn swiftly unlocked efficient forms of narrative, allowing early humans to learn much more about their kind than they could experience at first hand, so that they could cooperate and compete better through understanding one another more fully. This changed the payoff of sociality for individuals and groups. But true narrative was still limited to what had already happened. Once the strong existing predisposition to play combined with existing capacities for event comprehension, memory, imagination, language, and narrative, we could begin to invent fiction, and to explore the full range of human possibilities in concentrated, engaging, memorable forms. First language, then narrative, then fiction, created niches that altered selection pressures, and made us ever more deeply dependent on knowing more about our kind and our risks and opportunities than we could discover through direct experience. WIREs Cogn Sci 2018, 9:e1444. doi: 10.1002/wcs.1444

This article is categorized under: 1

Cognitive Biology > Evolutionary Roots of Cognition

2

Linguistics > Evolution of Language

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Neuroscience > Cognition

Children's Play and Culture Learning in an Egalitarian Foraging Society

Few systematic studies of play in foragers exist despite their significance for understanding the breadth of contexts for human development and the ontogeny of cultural learning. Forager societies lack complex social hierarchies, avenues for prestige or wealth accumulation, and formal educational institutions, and thereby represent a contrast to the contexts of most play research. Analysis of systematic observations of children's play among Aka forest foragers (n = 50, ages 4-16, M = 9.5) and Ngandu subsistence farmers (n = 48, ages 4-16, M = 9.1) collected in 2010 illustrates that while play and work trade off during development in both groups, and consistent patterns in sex-role development are evident, Aka children engage in significantly less rough-and-tumble play and competitive games than children among their socially stratified farming neighbors.

Play-solicitation gestures in chimpanzees in the wild: flexible adjustment to social circumstances and individual matrices

Social play is a frequent behaviour in great apes and involves sophisticated forms of communicative exchange. While it is well established that great apes test and practise the majority of their gestural signals during play interactions, the influence of demographic factors and kin relationships between the interactants on the form and variability of gestures are relatively little understood. We thus carried out the first systematic study on the exchange of play-soliciting gestures in two chimpanzee (Pan troglodytes) communities of different subspecies. We examined the influence of age, sex and kin relationships of the play partners on gestural play solicitations, including object-associated and self-handicapping gestures. Our results demonstrated that the usage of (i) audible and visual gestures increased significantly with infant age, (ii) tactile gestures differed between the sexes, and (iii) audible and visual gestures were higher in interactions with conspecifics than with mothers. Object-associated and self-handicapping gestures were frequently used to initiate play with same-aged and younger play partners, respectively. Our study thus strengthens the view that gestures are mutually constructed communicative means, which are flexibly adjusted to social circumstances and individual matrices of interactants.

An Exploratory Examination of Interpersonal Interactions between Peers in Informal Sport Play Contexts

Athlete-driven informal sport play represents an important context for athlete development. However, in contrast to coach-driven organized sport, little is known about the interpersonal processes driving development in this context. The present study was an exploratory descriptive analysis of the interactive peer behaviors occurring in an informal sport play setting and their relationship to athlete psychological characteristics. Thirty young athletes (<25 years old, M_age = 19.84) participating in informal mixed-age volleyball, soccer, and basketball sessions at a community recreation center were observed and their interactive behavior coded. Participants also completed questionnaire measures of psychological characteristics (competence, confidence, character). Descriptive analyses examined the interaction patterns of young athletes in these contexts. Multiple regression analyses were then conducted to examine the relationships between peer interactive behavior and athlete psychological characteristics. Results point to the social nature of participation in informal sport play contexts and the critical relationship between athlete competence and peer interaction tendencies. This study presents an initial exploration of peer interactive behavior in informal, mixed-age sport play contexts, but continued future research is needed to better understand the developmental processes and implications of participation in these important contexts.