The perceived support of supernatural agents has been historically, ethnographically, and theoretically linked with confidence in engaging in violent intergroup conflict. However, scant experimental investigations of such links have been reported to date, and the extant evidence derives largely from indirect laboratory methods of limited ecological validity. Here, we experimentally tested the hypothesis that perceived supernatural aid would heighten inclinations toward coalitional aggression using a realistic simulated coalitional combat paradigm: competitive team paintball. In a between-subjects design, US paintball players recruited (...) for the study were experimentally primed with thoughts of supernatural support using a guided visualization exercise analogous to prayer, or with a control visualization of a nature scene. The participants then competed in a team paintball battle game modeled after “Capture the Flag.” Immediately before and after the battle, participants completed surveys assessing confidence in their coalitional and personal battle performance. Participants assessed their coalition’s prospects of victory and performance more positively after visualizing supernatural aid. Participants primed with supernatural support also reported inflated assessments of their own performance. Importantly, however, covarying increases in assessments of their overall coalition’s performance accounted for the latter effect. This study provided support for the hypothesis that perceived supernatural support can heighten both prospective confidence in coalitional victory and retrospective confidence in the combat performance of one’s team, while highlighting the role of competitive play in evoking the coalitional psychology of intergroup conflict. These results accord with and extend convergent prior findings derived from laboratory paradigms far removed from the experience of combat. Accordingly, the field study approach utilized here shows promise as a method for investigating coalitional battle dynamics in a realistic, experientially immersive manner. (shrink)

We examine the ontogeny and phylogeny of object and fantasy play from a functional perspective. Each form of play is described from an evolutionary perspective in terms of its place in the total time and energy budgets of human and nonhuman juveniles. As part of discussion of functions of play, we examine sex differences, particularly as they relate to life in the environment of evolutionary adaptedness and economic activities of human and nonhuman primates. Object play may relate to foraging activities. (...) Although fantasy play has been viewed as limited to humans, we speculate that certain types of fantasy play may be present in some nonhuman primates. Fantasy play may enable juveniles to see situations from different perspectives. We conclude that fantasy play may have immediate effects and object play may have deferred effects. (shrink)

The hypothesis that play behavior is more prevalent in larger-brained animals has recently been challenged. It may be, for example, that only certain brain structures are related to play. Here, we analyze social play behavior with regards to the cerebellum: a structure strongly implicated in motor-development, and possibly also in cognitive skills. We present an evolutionary analysis of social play and the cerebellum, using a phylogenetic comparative method. Social play frequency and relative cerebellum size are positively correlated. Hence, there appears (...) to be a link between the evolutionary elaboration of social play and the cerebellum. (shrink)

Learning to use, make, and modify tools is key to our species’ success. Researchers have hypothesized that play with objects may have a foundational role in the ontogeny of tool use and, over evolutionary timescales, in cumulative technological innovation. Yet, there are few systematic studies investigating children’s interactions with objects outside the post-industrialized West. Here, we survey the ethnohistorical record to uncover cross-cultural trends regarding hunter-gatherer children’s use of objects during play and instrumental activities. Our dataset, consisting of 434 observations (...) of children’s toys and tools from 54 hunter-gatherer societies, reveals several salient trends: Most objects in our dataset are used in play. Children readily manufacture their own toys, such as dolls and shelters. Most of the objects that children interact with are constructed from multiple materials. Most of the objects in our dataset are full-sized or miniature versions of adult tools, reflecting learning for adult roles. Children also engage with objects related to child culture, primarily during play. Taken together, our findings show that hunter-gatherer children grow up playing, making, and learning with objects. (shrink)

Work-themed play may allow children to learn complex skills, and ethno-typical and gender-typical behaviors. Thus, play may have made important contributions to the evolution of childhood through the development of embodied capital. Using data from Aka foragers and Ngandu farmer children from the Central African Republic, we ask whether children perform ethno- and gender-typical play and work activities, and whether play prepares children for complex work. Focal follows of 50 Aka and 48 Ngandu children were conducted with the aim of (...) recording children’s participation in 12 categories of work and work-themed play. Using these data, we test a set of hypotheses regarding how age, gender, ethnicity, and task complexity influence children’s activities. As hypothesized, we find performance of work-themed play is negatively correlated with age. Contrary to our hypothesis, children do not play more than they work at complex tasks, but they work more than they play at simple ones. Gender and ethnicity are associated with play and work at culturally salient activities, despite availability of other-gender and other-ethnicity social partners. Our findings show that ethnic and gender biases are apparent in the play and work behavior of Aka and Ngandu children. Moreover, our results show that play helps both forager and farmer children learn complex skills, consistent with play having an adaptive learning function. (shrink)

This paper examines how innovative skills and knowledge are transmitted and acquired among adolescents in two hunter-gatherer communities, the Aka of southern Central African Republic and the Chabu of southwestern Ethiopia. Modes of transmission and processes of social learning are addressed. Innovation as well as social learning have been hypothesized to be key features of human cumulative culture, enhancing the fitness and survival of individuals in diverse environments. The innovation literature indicates adult males are more innovative than children and female (...) adults and therefore predicts that adolescents will seek out adult males. Further, the mode of transmission should be oblique. Thus, learning of innovations should be oblique or horizontal rather than vertical, with adolescents paying particular attention to “successful” innovative individuals. The social learning literature indicates that complex skills or knowledge is likely to be learned through teaching, and therefore that teaching will be an important process in the transmission of innovations. In-depth and semi-structured interviews, informal observations, and systematic free-listing were used to evaluate these hypotheses. The study found that cultural context patterned whether or not adolescents sought out adult male or female innovators; oblique modes of transmission were mentioned with greater frequency than horizontal or vertical modes; knowledge and skill bias was notable and explicitly linked by the adolescents to reproductive effort; and teaching was biased toward same-sex individuals and was an important but not an exclusive means of transmitting complex skills and social knowledge. (shrink)

This paper defends two initial claims. First, it argues that essentially the same cognitive resources are shared by adult creative thinking and problem-solving, on the one hand, and by childhood pretend play, on the other—namely, capacities to generate and to reason with suppositions (or imagined possibilities). Second, it argues that the evolutionary function of childhood pretence is to practice and enhance adult forms of creativity. The paper goes on to show how these proposals can provide a smooth and evolutionarily-plausible explanation (...) of the gap between the first appearance of our species in Southern Africa some 100,000 years ago, and the ‘creative explosion’ of cultural, technological and artistic change which took place within dispersed human populations some 60,000 years later. The intention of the paper is to sketch a proposal which might serve as a guide for future interdisciplinary research. 1 Introduction 2 Creativity and Pretence 3 Language and Creativity 4 Language and Cultural Accretions 5 Language, Play and Model-Building 6 Creativity, Protean Cognition and Sexual Selection 7 The Evolution of Pretence 8 The Emergence of Supposing 9 Pretence and Motivation 10 Two Objections 11 Conclusion. (shrink)

Tool use is a central topic in research on cognitive evolution and behavioral ecology in non-human animals. Originally thought to be a uniquely human phenomenon, many other species have been observed making and using tools for a variety of purposes, starting with Goodall’s groundbreaking work with chimpanzees in Gombe. Despite the frequent attention and great research interest in animal tool use, and ubiquity of the behavior, we argue here that chewing sticks by dogs should be included as a case of (...) tool use. We discuss alternate possible explanations and then propose several testable predictions regarding this hypothesis. We suggest that tool use may be more common than is often assumed and that many cases of animal tool use may be overlooked. (shrink)

Children’s play is widely believed by educators and social scientists to have a training function that contributes to psychosocial development as well as the acquisition of skills related to adult competency in task performance. In this paper we examine these assumptions from the perspective of life-history theory using behavioral observation and household economic data collected among children in a community in the Okavango Delta of Botswana where people engage in mixed subsistence regimes of dry farming, foraging, and herding. We hypothesize (...) that if play contributes to adult competency then time allocation to play will decrease as children approach adult levels of competence. This hypothesis generates the following predictions: (1) time allocated to play activities that develop specific productive skills should decline in relation to the proportion of adult competency achieved; (2) children will spend more time in forms of play that are related to skill development in tasks specific to the subsistence ecology in which that child participates or expects to participate; and (3) children will spend more time in forms of play that are related to skill development in tasks clearly related to the gender-specific productive role in the subsistence ecology in which that child participates or expects to participate. We contrast these expectations with the alternative hypothesis that if play is not preparatory for adult competence then time allocated to each play activity should diminish at the same rate. This latter hypothesis generates the following two predictions: (1) time allocation to play should be unaffected by subsistence regime and (2) patterns of time allocation to play should track patterns of growth and energy balance. Results from multiple regression analysis support earlier research in this community showing that trade-offs between immediate productivity and future returns were a primary determinant of children’s activity patterns. Children whose labor was in greater demand spent significantly less time playing. In addition, controlling for age and gender, children spent significantly more time in play activities related to tasks specific to their household subsistence economy. These results are consistent with the assertion that play is an important factor in the development of adult competency and highlight the important contributions of an evolutionary ecological perspective in understanding children’s developmental trajectories. (shrink)

Agency is a central concept in the organisational approach to organisms, which accounts for their internal purposiveness. Recent recognition of the active role played by organisms in evolution has led researchers to use this concept in an evolutionary approach. Agency is then considered in terms of ‘unintentional’ choice: agents choose from a given repertoire the behaviour most appropriate to their goal, with this choice influencing evolutionary pathways. This view, while allowing for the evolutionary role of the activity of organisms, presents (...) two pitfalls. First, it restricts organisms’ agency by confining their choice within the bounds of a behavioural repertoire, and assuming their goals are dictated by natural selection. Second, this view, while claiming to eliminate the idea of intentionality, retains its structure: organisms are portrayed as rational entities, persistently pursuing specific goals. This leads us back to a teleological thinking, whose use in evolutionary theory has already been heavily criticised. This paper proposes a conception of biological agency which does not assume goal-directedness but considers agency as inventiveness. An organism will be said to be an agent if it is the triggering cause of behaviours falling outside the known repertoire and whose form can only be explained by the unique relationship between the organism and the environment. If these behaviours have implications in evolution, the agent will be considered an evolutionary agent. The merit of this approach is further validated by evidencing the significant role behavioural innovations play in evolution. Finally, the last section delves into the process of invention by examining animal play. (shrink)