Do children imitate even when it is costly? New insights from a novel task.

Children have a proclivity to learn through faithful imitation, but the extent to which this applies under significant cost remains unclear. To address this, we investigated whether 4- to 6-year-old children (N = 97) would stop imitating to forego a desirable food reward. We presented participants with a task involving arranging marshmallows and craft sticks, with the goal being either to collect marshmallows or build a tower. Children replicated the demonstrated actions with high fidelity regardless of the goal, but retrieved rewards differently. Children either copied the specific actions needed to build a tower, prioritizing tower completion over reward; or adopted a novel convention of stacking materials before collecting marshmallows, and developed their own method to achieve better outcomes. These results suggest children's social learning decisions are flexible and context-dependent, yet that when framed by an ostensive goal, children imitated in adherence to the goal despite incurring significant material costs.

Children's distinct drive to reproduce costly rituals.

Costly rituals are ubiquitous and adaptive. Yet, little is known about how children develop to acquire them. The current study examined children's imitation of costly rituals. Ninety-three 4-6 year olds (47 girls, 45% Oceanians, tested in 2022) were shown how to place tokens into a tube to earn stickers, using either a ritualistic or non-ritualistic costly action sequence. Children shown the ritualistic actions imitated faithfully at the expense of gaining stickers; conversely, those shown the non-ritualistic actions ignored them and obtained maximum reward. This highlights how preschool children are adept at and motivated to learn rituals, despite significant material cost. This study provides insights into the early development of cultural learning and the adaptive value of rituals in group cognition.

Cultural evolution in the science of culture and cultural evolution.

My critical review [1] elicited a welcome diversity of perspectives across the 12 commentaries now published [2-13]. In total 28 co-authors were inspired to contribute. In addition to engaging with the critical perspectives of my review, several of the commentaries take the debates and discussions into insightful and potentially important supplementary domains that I highlight in what follows. I have extracted a number of major themes in which I detected overlaps in the foci of different commentaries, and I use these to organise my replies. I hope that our shared efforts will constitute some degree of 'cultural evolution' in our science, as suggested in the title of this reply to commentaries.

Conformity versus transmission in animal cultures.

The principal contrasts that Jagiello et al. highlight are among many cultural transmission biases we now know of. I suggest they are also reflected more widely in social learning decisions among nonhuman animal cultures governing whether cultural innovations spread, or are instead over-ridden by immigrants' conformity in their new group. Such conformity may serve either informational or social-integrative functions.

Blind alleys and fruitful pathways in the comparative study of cultural cognition.

A mere few decades ago, culture was thought a unique human attribute. Evidence to the contrary accumulated through the latter part of the twentieth century and has exploded in the present one, demonstrating the transmission of traditions through social learning across all principal vertebrate taxa and even invertebrates, notably insects. The scope of human culture is nevertheless highly distinctive. What makes our cultural capacities and their cognitive underpinnings so different? In this article I argue that in behavioural scientists' endeavours to answer this question, fruitful research pathways and their ensuing discoveries have come to exist alongside popular, yet in the light of current empirical evidence, highly questionable scenarios and even scientific blind alleys. I particularly re-evaluate theories that rely on the centrality of a supposed uniquely human capacity for imitative copying in explaining the distinctive capacity for massive cumulative cultural evolution (CCE) in our species. The most extreme versions of this perspective suffer logical incoherence and severe limits on scientific testability. By contrast the field has generated a range of rigorous observational and experimental methodologies that have revealed both long-term cultural fidelity and limited forms of CCE in non-human species. Attention now turns to directly investigating the scope, limits and underlying cognition of non-human versus human CCE, with a broader approach to factors additional to cultural transmission, notably the role of invention, innovation and evolved motivational biases underlying the scope of CCE in the species studied.

Cognitive flexibility supports the development of cumulative cultural learning in children.

The scale of cumulative cultural evolution (CCE) is a defining characteristic of humans. Despite marked scientific interest in CCE, the cognitive underpinnings supporting its development remain understudied. We examined the role cognitive flexibility plays in CCE by studying U.S. children's (N = 167, 3-5-year-olds) propensity to relinquish an inefficient solution to a problem in favor of a more efficient alternative, and whether they would resist reverting to earlier versions. In contrast to previous work with chimpanzees, most children who first learned to solve a puzzlebox in an inefficient way switched to an observed, more efficient alternative. However, over multiple task interactions, 85% of children who switched reverted to the inefficient method. Moreover, almost all children in a control condition (who first learned the efficient method) switched to the inefficient method. Thus, children were keen to explore an alternative solution but, like chimpanzees, are overall conservative in reverting to their first-learned one.

Collective knowledge and the dynamics of culture in chimpanzees.

Social learning in non-human primates has been studied experimentally for over 120 years, yet until the present century this was limited to what one individual learns from a single other. Evidence of group-wide traditions in the wild then highlighted the collective context for social learning, and broader 'diffusion experiments' have since demonstrated transmission at the community level. In the present article, we describe and set in comparative perspective three strands of our recent research that further explore the collective dimensions of culture and cumulative culture in chimpanzees. First, exposing small communities of chimpanzees to contexts incorporating increasingly challenging, but more rewarding tool use opportunities revealed solutions arising through the combination of different individuals' discoveries, spreading to become shared innovations. The second series of experiments yielded evidence of conformist changes from habitual techniques to alternatives displayed by a unanimous majority of others but implicating a form of quorum decision-making. Third, we found that between-group differences in social tolerance were associated with differential success in developing more complex tool use to exploit an increasingly inaccessible resource. We discuss the implications of this array of findings in the wider context of related studies of humans, other primates and non-primate species. This article is part of a discussion meeting issue 'The emergence of collective knowledge and cumulative culture in animals, humans and machines'.

The ontogeny of selective social learning: Young children flexibly adopt majority- or payoff-based biases depending on task uncertainty.

Humans have adapted well to diverse environments in part because of their ability to efficiently acquire information from their social environment. However, we still know very little as to how young children acquire cultural knowledge and in particular the circumstances under which children prioritize social learning over asocial learning. In this study, we asked whether children will selectively adopt either a majority-biased or payoff-biased social learning strategy in the presence or absence of asocial learning. The 3- to 5-year-olds (N = 117) were first shown a video in which four other children took turns in retrieving a capsule housing a reward from one of two boxes. Three of the children (the "majority") retrieved a capsule from the same box, and a single individual (the "minority") retrieved a capsule from the alternative box. Across four conditions, we manipulated both the value of the rewards available in each box (equal or unequal payoff) and whether children had knowledge of the payoff before making their own selection. Results show that children adopted a majority-biased learning strategy when they were unaware of the value of the rewards available but adopted a payoff-biased strategy when the payoff was known to be unequal. We conclude that children are strategic social learners who integrate both social and asocial learning to maximize personal gain.

Social learning from media: The need for a culturally diachronic developmental psychology.

Since the proliferation of television sets into households began over half a century ago there has been widespread interest in the impact that viewing has on young children's development. Such interest has grown with the increasing availability of smart phones and tablets. In this review we examine the literature documenting human social learning and how this learning is impacted when the instructing agent appears on a screen instead of face-to-face. We then explore the shifting nature of screen-based media, with a focus on the increasingly socio-normative manner information is portrayed. We discuss how the changing nature of screen technology might be altering how children interpret what they see, and raise the possibility that this may render prevailing evidence as historical documentation, rather than setting out established developmental milestones that transcend the period in which they were documented. We contend that recognizing the significance of historically changing contexts in developmental psychology is timely when the COVID-19 climate is pushing data collection on-line for many labs, often using tasks that were developed primarily for face-to-face contexts.

The burgeoning reach of animal culture.

Culture can be defined as all that is learned from others and is repeatedly transmitted in this way, forming traditions that may be inherited by successive generations. This cultural form of inheritance was once thought specific to humans, but research over the past 70 years has instead revealed it to be widespread in nature, permeating the lives of a diversity of animals, including all major classes of vertebrates. Recent studies suggest that culture's reach may extend also to invertebrates-notably, insects. In the present century, the reach of animal culture has been found to extend across many different behavioral domains and to rest on a suite of social learning processes facilitated by a variety of selective biases that enhance the efficiency and adaptiveness of learning. Far-reaching implications, for disciplines from evolutionary biology to anthropology and conservation policies, are increasingly being explored.

A deepening understanding of animal culture suggests lessons for conservation.

A key goal of conservation is to protect biodiversity by supporting the long-term persistence of viable, natural populations of wild species. Conservation practice has long been guided by genetic, ecological and demographic indicators of risk. Emerging evidence of animal culture across diverse taxa and its role as a driver of evolutionary diversification, population structure and demographic processes may be essential for augmenting these conventional conservation approaches and decision-making. Animal culture was the focus of a ground-breaking resolution under the Convention on the Conservation of Migratory Species of Wild Animals (CMS), an international treaty operating under the UN Environment Programme. Here, we synthesize existing evidence to demonstrate how social learning and animal culture interact with processes important to conservation management. Specifically, we explore how social learning might influence population viability and be an important resource in response to anthropogenic change, and provide examples of how it can result in phenotypically distinct units with different, socially learnt behavioural strategies. While identifying culture and social learning can be challenging, indirect identification and parsimonious inferences may be informative. Finally, we identify relevant methodologies and provide a framework for viewing behavioural data through a cultural lens which might provide new insights for conservation management.

Chimpanzees' behavioral flexibility, social tolerance, and use of tool-composites in a progressively challenging foraging problem.

Behavioral flexibility is a critical ability allowing animals to respond to changes in their environment. Previous studies have found evidence of inflexibility when captive chimpanzees are faced with changing task parameters. We provided two groups of sanctuary-housed chimpanzees with a foraging task in which solutions were restricted over time. Initially, juice could be retrieved from within a tube by hand or by using tool materials, but effective solutions were then restricted by narrowing the tube, necessitating the abandonment of previous solutions and adoption of new ones. Chimpanzees responded flexibly, but one group increased their use of effective techniques to a greater extent than the other. Tool-composite techniques emerged in both groups, but primarily in the more flexible group. The more flexible group also showed higher rates of socio-positive behaviors at the task. In conjunction, these findings support the hypothesis that social tolerance may facilitate the emergence and spread of novel behaviors.

Does culture shape hunting behavior in bonobos?

New evidence that neighboring communities of bonobos hunt different prey species, despite extensive overlaps in where they live and hunt, is difficult to explain without invoking cultural factors.

Refining our understanding of the "elephant in the room".

The authors do the field of cultural evolution a service by exploring the role of non-social cognition in human cumulative technological culture, truly neglected in comparison with socio-cognitive abilities frequently assumed to be the primary drivers. Some specifics of their delineation of the critical factors are problematic, however. I highlight recent chimpanzee-human comparative findings that should help refine such analyses.

A unified account of culture should accommodate animal cultures.

Discoveries about social learning and culture in non-human animals have burgeoned this century, yet despite aspiring to offer a unified account of culture, the target article neglects these discoveries almost totally. I offer an overview of principal findings in this field including phylogenetic reach, intraspecies pervasiveness, stability, fidelity, and attentional funnelling in social learning. Can the authors' approach accommodate these?