The burgeoning reach of animal culture

Cold-blooded culture? Assessing cultural behaviour in reptiles and its potential conservation implications

It is becoming clear that the cognition of a species plays an important role in successful conservation, with cultural processes being a fundamental part of this. However, in contrast to mammals and birds, very little is known about cultural processes (and the social learning that underlies these) in reptiles. Here, we summarize the current state of knowledge, consider why this information is so limited and assess candidate behaviours observed in the wild, which warrant further investigation through the lens of cultural traditions. We then make suggestions for the fundamental next steps necessary to start to address this issue. This includes future experimental work and also consideration of how existing datasets, such as those capturing animal movement or acoustic activity, can be used to assess cultural questions. In addition, we emphasize the important role that engaging key conservation stakeholders, such as zoos, aquaria and ecotourism providers, could play in furthering our understanding of cultural behaviour in this group and the potential conservation implications of this knowledge. Whether there is cultural behaviour in reptiles and the relationship that this has with conservation remain unclear; however, the findings of this review suggest that these are areas worthy of further research.This article is part of the theme issue 'Animal culture: conservation in a changing world'.

The effect of habitat health and environmental change on cultural diversity and richness in animals

There is increasing evidence that habitat decline via fragmentation or species loss can lead to loss of cultural diversity, complexity or richness in non-human animals. For example, a reduction in local bird species richness leads lyrebirds to sing fewer complex songs, while great apes living in fragmented landscapes have smaller cultural repertoires. However, the link between animal culture and local ecology remains understudied, and the potentially complex interactions between ongoing ecological change and animal culture are poorly understood. Here, we review the current state of knowledge on how ecology influences animal culture, focusing on vocal communication and foraging behaviour. We identify key factors affecting cultural patterning, including direct effects (e.g. environmental variability) and indirect effects (e.g. connectivity). We then review the emerging evidence for the effects of environmental change on culture, identifying three major threatening processes: habitat fragmentation, habitat degradation and urbanization. Finally, we develop a predictive framework for the effect of these threatening processes on animal culture and highlight how the loss of cultural diversity and complexity can lead to fitness costs with conservation implications.This article is part of the theme issue 'Animal culture: conservation in a changing world'.

Animal culture: conservation in a changing world

Social learning and animal culture can influence conservation outcomes in significant ways. Culture is a dynamic phenomenon; socially learned behaviours can be transmitted within and/or between generations and among populations, which can facilitate resilience, or in other circumstances generate vulnerability. Culture can be a driver of evolutionary diversification, population structure and demography, shaping sociality and influencing underlying biological processes such as reproduction and survival, affecting fitness. This theme issue synthesizes the current state of knowledge on cultural variation within major vertebrate taxa, offering practical insights on how social learning can interface directly with conservation interventions. It ranges over topics that include translocations, human-wildlife interactions and adaptation to anthropogenic change. Culture is complex; integrating cultural processes into conservation is challenging. No one-size-fits-all policy can be recommended. Instead, we aim to balance current understanding of underlying processes with a diversity of practical implementations in this nascent field, exploring and supporting developing pathways towards conservation efficiencies. Key themes that emerge include conserving cultural capacity, benefits of data sharing, along with the intrinsic value of animal cultures and the role of Indigenous Peoples and local communities.This article is part of the theme issue 'Animal culture: conservation in a changing world'.

Worlds that collide: conservation applications of behaviour and culture in human-wildlife interactions

The behaviour of both humans and wildlife is central to the conservation of biodiversity because conservation requires human actions at multiple scales. In species with evidence of socially learned behaviour and culture, the juxtaposition of human and animal culture increases the complexity of human-wildlife interactions and their investigation but also offers opportunities to mitigate negative interactions. In this paper, we consider the language used to analyse human-animal interactions and we review the effect of culture and socially learned behaviours on those interactions. We investigate how knowledge of culture and theory from behavioural studies can be used to negotiate the complex interactions between humans and wildlife, providing specific examples of how culture can be mined for developing policies regarding negative interactions. We highlight that interactions between animal and human culture are central to the conservation of wildlife, and that such human-wildlife interactions are a key target for studies of biodiversity conservation. Integrating culture and social learning into conservation research offers scope to leverage knowledge gaps, misconceptions and concerns into conservation actions that are targeted, relevant and meaningful.This article is part of the theme issue 'Animal culture: conservation in a changing world'.

Integrating culture into primate conservation

Primates exhibit the richest cultural repertoire among animal taxa, spanning foraging, communication, sociality and tool use. Understanding the cultural behaviours of primates has strongly influenced the study of animal behaviour and challenged traditional views that culture is exclusive to humans. With nearly 60% of primate species endangered owing to human-driven habitat changes, recent calls have emerged to integrate cultural diversity into conservation strategies. However, the integration of culture into primate conservation requires careful planning to avoid misallocation of resources or skewed conservation priorities. Our review reveals that studies on primate culture are limited to less than 3% of extant species, largely owing to taxonomic and methodological biases favouring long-term observations in protected habitats. We propose that including culture in conservation policies can broaden the scope of research, fostering more inclusive conservation agendas that address taxa with diverse habitats and underexplored cultural traits. Furthermore, anthropogenic habitat changes can both erode and foster cultural behaviours, emphasizing the need for context-specific conservation strategies. We suggest that recognizing cultural traits in conservation frameworks may enhance the resilience of primate populations in changing environments. This approach promises a more comprehensive and equitable allocation of conservation efforts, preserving both the biological and cultural diversity of primates.This article is part of the theme issue 'Animal culture: conservation in a changing world'.

Network indicators of cultural resilience to anthropogenic removals in animal societies

Social learning, information transmission and culture play vital roles in the lives of social animals, influencing their survival, reproduction and ability to adapt to changing environments. However, the effect of anthropogenic disturbances on these processes is poorly understood in free-living animals. To investigate the impact of anthropogenic disturbance on social learning and information transmission, we simulated individual removal from contact networks derived from long-term behavioural datasets. We simulate the effects of individual removal on network efficiency and social learning for three group-living species-yellow baboons (Papio cynocephalus), African savanna elephants (Loxodonta africana) and Indo-Pacific bottlenose dolphins (Tursiops aduncus). We reveal how removals of key network positions reduce network efficiency. However, groups with high levels of innovation may cope with changing social network structures. These findings highlight the importance of protecting key individuals to preserve group structure and the role of innovation in possibly mitigating the fitness costs of removals. Identifying and safeguarding individuals that drive innovation can reduce a group's susceptibility to anthropogenic threats and promote cultural resilience in social animals in a changing world. These emerging trends contribute to a growing understanding of the role of conservation interventions in protecting critical individuals in group-living animals.This article is part of the theme issue 'Animal culture: conservation in a changing world'.

The growing methodological toolkit for identifying and studying social learning and culture in non-human animals

There is a growing consensus that animals' socially transmitted knowledge should be recognized when planning conservation management, but demonstrating social learning or culture can present considerable challenges, especially in the wild. Fortunately, decades of research have spawned a rich methodological toolkit for exactly this purpose. Here, we review principal approaches, including: social learning experiments; analyses of natural or experimentally seeded diffusions of novel behaviours, sometimes using specialist statistical techniques; mapping of behavioural variation across neighbouring, sympatric or captive groups, or at larger scales; and assessment of aspects of cross-generational transmission, including teaching, learning during ontogenetic development and cumulative change. Some methods reviewed were developed for captive studies, but have subsequently been adapted for application in the wild, or are useful for exploring a species' general propensity to learn and transmit information socially. We highlight several emerging 'rapid assessment' approaches-including camera trapping, passive acoustic monitoring, animal-borne tags, AI-assisted data mining and computer simulations-that should prove useful in addressing particularly urgent conservation needs. We conclude by considering how best to use this growing methodological toolkit in practice, to guide further research on animal social learning and cultures, and maximize conservation and policy impact.This article is part of the theme issue 'Animal culture: conservation in a changing world'.

Cultural processes and demography: implications for conservation and beyond

Social transmission of cultural variants in wildlife can cause population level effects with implications for conservation science, policy and practice. Social learning and animal culture can generate resilience in populations through the spread of adaptive behaviour but may also generate vulnerabilities. Distilling comprehensive management advice in this field remains challenging. Animal culture is important for defining 'units to conserve', managing human-wildlife interactions, reintroductions or translocations, and influences evolutionary change. However, the population level effects of cultural processes remain poorly understood. Given the breadth of issues for which cultural processes inform conservation, it is timely to consider the underlying processes in more detail. We consider the coupling of cultural processes and population dynamics to explore the conditions under which social learning can tip a declining population into growth. Simulations on a model system of two interacting cultural units are used to explore the tensions between the coupled dynamics of cultural and demographic processes. We show that even under a simple learning bias, the population level outcomes are complex. In concert with urgent targeted conservation action, we highlight the need to develop deeper process-based understanding in this field, to yield fundamental principles applicable to a broader range of encultured species.This article is part of the theme issue 'Animal culture: conservation in a changing world'.

Integrating cultural dimensions in sperm whale (Physeter macrocephalus) conservation: threats, challenges and solutions

Culture-socially transmitted behaviours shared within a community-can influence animal populations' structure, vulnerability and resilience. Clans of sperm whales in the Eastern Tropical Pacific (ETP) exemplify the profound influence of culture on these dynamics and highlight the challenges of accounting for culture in conservation efforts. Globally, sperm whales are classified as vulnerable, and the ETP sperm whale population has struggled to reach a positive growth rate. This stagnation is partly due to cumulative anthropogenic threats in the region, including fishing conflicts, vessel traffic, pollution, deep sea mining, oil and gas exploration, and anthropogenic climate change. The United Nations Convention on Migratory Species adopted a Concerted Action for ETP sperm whales in 2017, proposing collaborative efforts to address cultural dimensions in conservation. However, knowledge gaps and real-world implementation challenges persist. Here, we review the role of social transmission in shaping sperm whale behaviour and populations, outline current anthropogenic threats and environmental stressors they face in the ETP, and discuss the ongoing challenges of incorporating cultural dimensions into large-scale international conservation efforts. Strengthening transnational collaboration and capitalizing on new technologies for efficient analysis can help bridge these knowledge gaps and enhance future research on this iconic species.This article is part of the theme issue 'Animal culture: conservation in a changing world'.

Knowledge transmission, culture and the consequences of social disruption in wild elephants

Cultural knowledge is widely presumed to be important for elephants. In all three elephant species, individuals tend to congregate around older conspecifics, creating opportunities for social transmission. However, direct evidence of social learning and cultural traditions in elephants is scarce. Here, we briefly outline that evidence then provide a systematic review of how elephant societies respond to the loss of potentially knowledgeable individuals or opportunities for knowledge transfer, which we characterize as social disruption. We consider observations from 95 peer-reviewed, primary research papers that describe disruption to elephant societies or networks via the removal or death of individuals. Natural deaths were mentioned in 14 papers, while 70 detailed human-caused deaths or disruption. Grouping descriptions according to consequences for behaviour and sociality, and demography and fitness, we show that severely disrupted populations are less cohesive, may exhibit reduced fitness or calf survival and respond inappropriately to threats and predators. We suggest that severe social disruption can inhibit or break potential pathways of information transmission, providing indirect evidence for the role of social transmission in elephants. This has implications for elephant conservation amid increasing anthropogenic change across their habitats.This article is part of the theme issue 'Animal culture: conservation in a changing world'.

Concerted conservation actions to support chimpanzee cultures

Chimpanzees were among the first animals recognized to have culture, and our understanding of the breadth of their cultural repertoire has grown significantly since the 1960s. Throughout their range, chimpanzee populations have come under increasing pressure, with their endangered status necessitating immediate and long-term conservation interventions. Recognizing the importance of diverse behavioural repertoires for chimpanzees' survival, there has been a recent focus of conservation efforts on preserving their culturally transmitted behaviours and the environments in which they are exhibited. This article evaluates the practicality of developing conservation measures focused on chimpanzee culture. We highlight innovative conservation strategies aimed at integrating chimpanzee cultural behaviours into conservation policies. We review synergistic conservation initiatives led by the International Union for Conservation of Nature, the UN Convention on the Conservation of Migratory Species of Wild Animals and other international and local groups that share the goal of preserving chimpanzee populations and their cultural diversity. We underline how successful conservation implementation requires engagement and collaboration with a diverse group of interested or affected people. Finally, we provide recommendations aimed at guiding future efforts to incorporate animal cultures into conservation strategies.This article is part of the theme issue 'Animal culture: conservation in a changing world'.

Saving the cultural legacy of wild animals

Loss of biodiversity threatens the study of tool use and other cultural behaviors in animals.

The cultural evolution of distortion in music (and other norms of mixed appeal)

Music traditions worldwide are subject to remarkable diversity but the origins of this variation are not well understood. Musical behaviour is the product of a multicomponent collection of abilities, some possibly evolved for music but most derived from traits serving nonmusical functions. Cultural evolution has stitched together these systems, generating variable normative practices across cultures and musical genres. Here, we describe the cultural evolution of musical distortion, a noisy manipulation of instrumental and vocal timbre that emulates nonlinear phenomena (NLP) present in the vocal signals of many animals. We suggest that listeners' sensitivity to NLP has facilitated technological developments for altering musical instruments and singing with distortion, which continues to evolve culturally via the need for groups to both coordinate internally and differentiate themselves from other groups. To support this idea, we present an agent-based model of norm evolution illustrating possible dynamics of continuous traits such as timbral distortion in music, dependent on (i) a functional optimum, (ii) intra-group cohesion and inter-group differentiation and (iii) groupishness for assortment and social learning. This account illustrates how cultural transmission dynamics can lead to diversity in musical sounds and genres, and also provides a more general explanation for the emergence of subgroup-differentiating norms.This article is part of the theme issue 'Nonlinear phenomena in vertebrate vocalizations: mechanisms and communicative functions'.

Origin stories: how does learned migratory behaviour arise in populations?

Although decades of research have deepened our understanding of the proximate triggers and ultimate drivers of migrations for a range of taxa, how populations establish migrations remains a mystery. However, recent studies have begun to illuminate the interplay between genetically inherited and learned migrations, opening the door to the evaluation of how migration may be learned, established, and maintained. Nevertheless, for migratory species where the role of learning is evident, we lack a comprehensive framework for understanding how populations learn specific routes and refine migratory movements over time (i.e., their origins). This review draws on advances in behavioural and movement ecology to offer a comprehensive framework for how populations could transition from resident to migratory by connecting cognitive research on fine-scale perceptual cues and movement decisions with literature on learning and cultural transmission, to the emergent pattern of migration. We synthesize the multiple cognitive mechanisms and processes that allow a population to respond to seasonal resource limitation, then encode spatial and environmental information about resource availability in memory and engage in social learning to navigate their landscapes and track resources better. A rise in global reintroduction efforts, along with human-induced rapid shifts in environmental cues and changing landscapes make evaluating the origins of this threatened behaviour more urgent than ever.

Social tolerance and role model diversity increase tool use learning opportunities across chimpanzee ontogeny

Social learning opportunities shape cognitive skills across species, especially in humans. Although the social environment impacts learning opportunities, the benefits of role model diversity and tolerance on task learning in tool-using species remain poorly understood. To explore these links, we study 2343 peering events (close-range observation of a conspecific) from 35 wild immature (<10 y) chimpanzees (Pan troglodytes verus). We find that chimpanzee peering functions to acquire information more than food, persists during development while peaking around weaning age, and increases with food processing complexity. Role models change throughout development, with increased peering at mothers during early stages and for more complex tasks. Finally, immatures observe many role models, favouring older and more tolerant individuals. We conclude that chimpanzees learn from multiple tolerant individuals, particularly when acquiring complex skills like tool use. Tolerant societies may be necessary for the acquisition and retention of the diverse tool kits rarely found in nature.

Nostalgia Promotes Parents' Tradition Transfer to Children by Strengthening Parent-Child Relationship Closeness

Parental tradition transfer to children is pivotal for their socialization, identity formation, and culture perpetuation. But what motivates parents to transfer traditions to their children? We hypothesized that nostalgia, an emotion strengthening interpersonal bonds, would promote tradition transfer through parent-child relationship closeness. We tested these hypotheses using cross-sectional (Studies 1 and 4), cross-lagged (Study 2 and preregistered Study 5), and experimental (Studies 3 and 6) designs. In Studies 1 to 3, nostalgia was associated with, had lagged effect on, and promoted tradition transfer. In Studies 4-6, parent-child relationship closeness mediated the link between nostalgia and tradition transfer. The findings enrich our understanding of the vertical transmission of knowledge, customs, and values, offering insight into how intergenerational bonds are reinforced and cultural heritage is maintained.

A sequence bottleneck for animal intelligence and language?

We discuss recent findings suggesting that non-human animals lack memory for stimulus sequences, and therefore do not represent the order of stimuli faithfully. These observations have far-reaching consequences for animal cognition, neuroscience, and studies of the evolution of language and culture. This is because, if non-human animals do not remember or process information about order faithfully, then it is unlikely that non-human animals perform mental simulations, construct mental world models, have episodic memory, or transmit culture faithfully. If this suggested sequence bottleneck proves to be a prevalent characteristic of animal memory systems, as suggested by recent work, it would require a re-examination of some influential concepts and ideas.

Convergent evolution in whale and human vocal cultures

The complex songs of humpback whales conform to fundamental laws of language.

Signal traditions and cultural loss in chimpanzees

The horizontal transmission of cultural knowledge is a powerful mechanism of evolutionary change1. Across taxa, group-specific cultural traditions are expressed in diverse contexts, such as foraging, tool use, self-care and socialization2. These traditions arise when group members converge on specific behavioral phenotypes. When these behavioral phenotypes involve communicative signals, such as gestures, they are termed dialects3. However, gestural dialects are rare in non-humans3. Behavioral phenotypes and traditions can also be lost, a well-documented phenomenon in humans4, but rarely documented in non-human animals5. Here, we find that chimpanzee gestures produced in copulation solicitations show culturally established phenotypes and undergo cultural loss due to human-induced population decline.

What we know and don't know about great ape cultural communication in the wild

Following the first descriptions of culture in primates, widespread agreement has developed that the term can be applied to nonhumans as group-specific, socially learned behaviors. While behaviors such as those involving extractive tool use have been researched intensively, we propose that behaviors that are more subtle, less likely to be ecologically constrained, and more likely to be socially shaped, such as cultural forms of communication, provide compelling evidence of culture in nonhuman primates. Additionally, cultural forms of communication can provide novel insights into animal cognition such as the capacity for conformity, conventionalized meanings, arbitrariness in signal forms, and even symbolism. In this paper we focus on evidence from studies conducted on wild great apes. First, we provide a thorough review of what exactly we do know, and by extension don't know, about great ape cultural communication. We argue that detailed research on both vocal and gestural communication in wild great apes shows a more nuanced and variable repertoire than once assumed, with increasing support for group-specific variation. Second, we discuss the relevance of great ape cultural communication and its potential for illustrating evolutionary continuity for human-like cultural attributes, namely cumulative culture and symbolism. In sum, a concerted effort to examine cultural forms of communication in great apes could reveal novel evidence for cultural capacities that have thus far been heavily debated in the literature and can simultaneously contribute to an improved understanding of the complex minds of our closest living relatives.

Multifunctional Network-Shaped Hydrogel Assemblies

The previously reported hydrogel assemblies carry bulky shapes, for which the unitary assembly form immensely restricted further applications. Yet there are abundant natural examples of network-shaped assemblies constructed by animals, of which it is brought up inspirations for constructing hydrogel assemblies. Herein, the network-shaped assemblies with diverse functions are reported. The precursor solutions are prepared by acrylamide, 4-acryloylmorpholine, choline chloride, and photo-initiators. By means of three dimension (3D) printing, the hydrogel networks are formed driven by hydrogen bonds, and then the prepared jagged hydrogel blocks are assembled into network-shaped hydrogel assembly NSHA-0 by weaving method. Benefitting from the modifiability of hydrogels, hydrogel assemblies with different properties and functions are prepared by incorporating different functional monomers including ion pair acryloyloxyethyl trimethyl ammonium chloride, and sodium p-styrenesulfonate, N-isopropylacrylamide, spiropyran derivative and tetra-(4-pyridylphenyl)ethylene. The incorporation of these monomers bestowed the assemblies self-healing ability, thermo-responsiveness, ultraviolet-responsiveness as well as acid-responsiveness respectively.

Social tolerance and success-biased social learning underlie the cultural transmission of an induced extractive foraging tradition in a wild tool-using primate

The last two decades have seen great advances in the study of social learning (learning from others), in part due to efforts to identify it in the wild as the basis of behavioral traditions. Theoretical frameworks suggest that both the dynamics of social tolerance and transmission biases (or social learning strategies) influence the pathways of information diffusion in social groups. Bearded capuchins (Sapajus libidinosus) inhabiting the semiarid seasonal caatinga biome of the Serra da Capivara National Park (SCNP) form highly tolerant societies that possess the largest "tool-kit" described for monkeys, a feat likely facilitated by social learning. Here, we used social network analysis and an open diffusion experiment using an extractive foraging task to identify the occurrence of social learning and describe the pathways of social transmission of information in two wild primate populations. The dynamics of social tolerance outside of task introductions predicted opportunities for social learning, but it was tolerance during task introductions that predicted the actual pathways of social information diffusion. Our results also indicated that the capuchins mainly learned from others via direct observation and naïve individuals exhibited an observation bias toward successful males. This study supports the claims of cultural transmission in robust capuchins and empirically supports the role of social tolerance and social learning strategies in human and nonhuman primate cultural evolution.

Culture in humans and other animals

Migration provides evidence for cumulative cultural evolution in chimpanzees.

Population connectivity shapes the distribution and complexity of chimpanzee cumulative culture

Although cumulative culture is a hallmark of hominin evolution, its origins can be traced back to our common ancestor with chimpanzees. Here, we investigated the evolutionary origins of chimpanzee cumulative culture and why it remained incipient. To trace cultural transmission among the four chimpanzee subspecies, we compared population networks based on genetic markers of recent migration and shared cultural traits. We show that limited levels of group connectivity favored the emergence of a few instances of cumulative culture in chimpanzees. As in humans, cultural complexification likely happened in steps, with transmission between populations, incremental changes, and repurposing of technologies. We propose that divergence in social patterns led to increased mobility between groups in the genus Homo, resulting in irreversible dependence on cultural exchange and complexification.

Architectural traditions in the structures built by cooperative weaver birds

Humans cooperate to build complex structures with culture-specific architectural styles. However, they are not the only animals to build complex structures nor to have culture. We show that social groups of white-browed sparrow weavers (Plocepasser mahali) build structures (nests for breeding and multiple single-occupant roosts for sleeping) that differ architecturally among groups. Morphological differences are consistent across years and are clear even among groups with territories a few meters apart. These repeatable differences are not explained by among-group variation in local weather conditions, bird size, tree height, or patterns of genetic relatedness. Architectural styles are also robust to the immigration of birds from other groups.

Evolved Open-Endedness in Cultural Evolution: A New Dimension in Open-Ended Evolution Research

The goal of Artificial Life research, as articulated by Chris Langton, is "to contribute to theoretical biology by locating life-as-we-know-it within the larger picture of life-as-it-could-be." The study and pursuit of open-ended evolution in artificial evolutionary systems exemplify this goal. However, open-ended evolution research is hampered by two fundamental issues: the struggle to replicate open-endedness in an artificial evolutionary system and our assumption that we only have one system (genetic evolution) from which to draw inspiration. We argue not only that cultural evolution should be seen as another real-world example of an open-ended evolutionary system but that the unique qualities seen in cultural evolution provide us with a new perspective from which we can assess the fundamental properties of, and ask new questions about, open-ended evolutionary systems, especially with regard to evolved open-endedness and transitions from bounded to unbounded evolution. Here we provide an overview of culture as an evolutionary system, highlight the interesting case of human cultural evolution as an open-ended evolutionary system, and contextualize cultural evolution by developing a new framework of (evolved) open-ended evolution. We go on to provide a set of new questions that can be asked once we consider cultural evolution within the framework of open-ended evolution and introduce new insights that we may be able to gain about evolved open-endedness as a result of asking these questions.

In search of animal normativity: a framework for studying social norms in non-human animals

Social norms - rules governing which behaviours are deemed appropriate or inappropriate within a given community - are typically taken to be uniquely human. Recently, this position has been challenged by a number of philosophers, cognitive scientists, and ethologists, who have suggested that social norms may also be found in certain non-human animal communities. Such claims have elicited considerable scepticism from norm cognition researchers, who doubt that any non-human animals possess the psychological capacities necessary for normative cognition. However, there is little agreement among these researchers about what these psychological prerequisites are. This makes empirical study of animal social norms difficult, since it is not clear what we are looking for and thus what should count as behavioural evidence for the presence (or absence) of social norms in animals. To break this impasse, we offer an approach that moves beyond contested psychological criteria for social norms. This approach is inspired by the animal culture research program, which has made a similar shift away from heavily psychological definitions of 'culture' to become organised around a cluster of more empirically tractable concepts of culture. Here, we propose an analogous set of constructs built around the core notion of a normative regularity, which we define as a socially maintained pattern of behavioural conformity within a community. We suggest methods for studying potential normative regularities in wild and captive primates. We also discuss the broader scientific and philosophical implications of this research program with respect to questions of human uniqueness, animal welfare and conservation.

Understanding the Role of Naive Learners in Cultural Change

AbstractA change to a population's social network is a change to the substrate of cultural transmission, affecting behavioral diversity and adaptive cultural evolution. While features of network structure such as population size and density have been well studied, less is understood about the influence of social processes such as population turnover-or the repeated replacement of individuals by naive individuals. Experimental data have led to the hypothesis that naive learners can drive cultural evolution by better assessing the relative value of behaviors, although this hypothesis has been expressed only verbally. We conducted a formal exploration of this hypothesis using a generative model that concurrently simulated its two key ingredients: social transmission and reinforcement learning. We simulated competition between high- and low-reward behaviors while varying turnover magnitude and tempo. Variation in turnover influenced changes in the distributions of cultural behaviors, irrespective of initial knowledge-state conditions. We found optimal turnover regimes that amplified the production of higher reward behaviors through two key mechanisms: repertoire composition and enhanced valuation by agents that knew both behaviors. These effects depended on network and learning parameters. Our model provides formal theoretical support for, and predictions about, the hypothesis that naive learners can shape cultural change through their enhanced sampling ability. By moving from experimental data to theory, we illuminate an underdiscussed generative process that can lead to changes in cultural behavior, arising from an interaction between social dynamics and learning.

Feathered Lectures-Evidence of Perceptual Factors on Social Learning in Kea Parrots (Nestor notabilis)

Social learning describes the acquisition of knowledge through observation of other individuals, and it is fundamental for the development of culture and traditions within human groups. Although previous studies suggest that Kea (Nestor notabilis) benefit from social learning, experimental evidence has been inconclusive, as in a recent two-action task, all perceptual factors were ignored. The present study attempts to address this by investigating social learning in Kea with a focus on social enhancement processes. In an experiment with a captive group of Kea, we investigated whether individuals that had the opportunity to observe a conspecific performing a simple task subsequently show better performance in that task than a control group without prior demonstration. This study provides a strong tendency of greater success in skill acquisition in Kea as a result of social learning. Kea that observed a conspecific solving a task showed clear evidence of perceptual factors drawing attention to the relevant parts of the experimental apparatus and manipulated these significantly more (100% of trials) than control birds (77.8% of trials). Combined with a strong trend (p = 0.056) of the test subjects solving the task more than the control subjects, this shows conclusively that Kea, at least when required to solve a task, do attend to perceptual factors of a demonstrated action.

Automatic identification of stone-handling behaviour in Japanese macaques using LabGym artificial intelligence

The latest advances in artificial intelligence technology have opened doors to the video analysis of complex behaviours. In light of this, ethologists are actively exploring the potential of these innovations to streamline the time-intensive behavioural analysis process using video data. Several tools have been developed for this purpose in primatology in the past decade. Nonetheless, each tool grapples with technical constraints. To address these limitations, we have established a comprehensive protocol designed to harness the capabilities of a cutting-edge artificial intelligence-assisted software, LabGym. The primary objective of this study was to evaluate the suitability of LabGym for the analysis of primate behaviour, focusing on Japanese macaques as our model subjects. First, we developed a model that accurately detects Japanese macaques, allowing us to analyse their actions using LabGym. Our behavioural analysis model succeeded in recognising stone-handling-like behaviours on video. However, the absence of quantitative data within the specified time frame limits the ability of our study to draw definitive conclusions regarding the quality of the behavioural analysis. Nevertheless, to the best of our knowledge, this study represents the first instance of applying the LabGym tool specifically for the analysis of primate behaviours, with our model focusing on the automated recognition and categorisation of specific behaviours in Japanese macaques. It lays the groundwork for future research in this promising field to complexify our model using the latest version of LabGym and associated tools, such as multi-class detection and interactive behaviour analysis.

Mapping nut-cracking in a new population of wild capuchin monkeys (Sapajus libidinosus) at Ubajara National Park, Brazil

Populations of bearded capuchin monkeys (Sapajus libidinosus) vary in their tool use behaviors, with some of this divergence regarded as culturally determined. The use of stone tools, primarily to crack open encased foods, is widespread among bearded capuchins living in dry habitats (Caatinga and Cerrado). Significant diversity in targets, processed foods, material, and size of tools is observed across populations. However, so far, only a few sites have been systematically studied, and we are still distant from a representative picture of the range of variation in capuchins' culture. In this study, we did a systematic assessment of stone tool use sites in the Ubajara National Park (UNP), in the Caatinga region of Ceará, Brazil, recording and measuring stone tools, processed foods, and available lithic resources as part of an extensive comparative research, the CapCult project. We found indirect and direct evidence that capuchin monkeys at UNP customarily use hammerstones and anvils to process at least two species of palm nuts, macauba (Acrocomia aculeata) and the harder babaçu (Attalea speciosa). Most of the anvils were rock surfaces and had leftovers of only one palm nut species. The hammerstones used to process both palm nuts were not significantly different in weight, although the ones used for Ac. aculeata were longer. We found a higher frequency of nut-cracking sites in the drier lowland area of the park, reflecting differences in the density of the most common palm species, Ac. aculeata, and availability of raw stone material. The stone tool use observed in UNP is within the scope of previously reported in savannah capuchin populations. Our study widens the knowledge of stone tool-use diversity in wild capuchin monkeys, which could contribute to shaping conservation policy, including cultural traits.

A close look at sociality in DSM criteria

PURPOSE

The importance of sociality in psychology and psychotherapy is quite undisputed; however, this construct risks being underestimated in psychiatric nosography. The aim of the review was to assess the relevance of sociality in DSM 5 criteria.

METHOD

Sociality-laden criteria of 192 selected DSM categories have been identified through a textual grid. Second, the criteria have been classified into 6 categories, i.e., (1) Affiliation and Attachment (AA), (2) Social Communication (SC), (3) Perception and Understanding of Others (PUO), (4) Culture, (5) Clinical Significance Criterion (CSC) (6), and No Specific Construct (NSC).

RESULTS

13% of all mental disorders mention AA in their criteria. 8.8% of all mental disorders mention SC; 8.8% of all mental disorders mention PUO in their criteria. 15% of all mental disorders mention culture in their criteria (exclusively ex negativo though). 40% of mental disorders mention non-specific sociality (NSC) in their criteria. CSC is mentioned in 85% of mental disorders. Personality disorders have the highest "concentration" of sociality mentions throughout the DSM categories.

CONCLUSIONS

The overall results suggest that DSM criteria offer a confused account of sociality. We believe that the descriptive approach is the underlying reason. We suggest that in the long run a theory-laden approach to sociality, informed by evolutionary insights about motivations, could be of help.

Population turnover, behavioral conservatism, and rates of cultural evolution

Cultural evolution facilitates behavioral adaptation in many species. The pace of cultural evolution can be accelerated by population turnover, where newcomers (immigrants or juvenile recruits) introduce adaptive cultural traits into their new group. However, where newcomers are naïve to the challenges of their new group, population turnover could potentially slow the rate of cultural evolution. Here, we model cultural evolution with population turnover and show that even if turnover results in the replacement of experienced individuals with naïve ones, turnover can still accelerate cultural evolution if (1) the rate of social learning is more than twice as fast as the turnover rate and (b) newcomers are more likely to learn socially than behaviorally conservative existing group members. Although population turnover is a relatively simple factor, it is common to all animal societies, and variation in the turnover rate may potentially play an important role in explaining variation in the occurrence and rates of adaptive cultural evolution across species.

Cultural evolution: A review of theoretical challenges

The rapid growth of cultural evolutionary science, its expansion into numerous fields, its use of diverse methods, and several conceptual problems have outpaced corollary developments in theory and philosophy of science. This has led to concern, exemplified in results from a recent survey conducted with members of the Cultural Evolution Society, that the field lacks 'knowledge synthesis', is poorly supported by 'theory', has an ambiguous relation to biological evolution and uses key terms (e.g. 'culture', 'social learning', 'cumulative culture') in ways that hamper operationalization in models, experiments and field studies. Although numerous review papers in the field represent and categorize its empirical findings, the field's theoretical challenges receive less critical attention even though challenges of a theoretical or conceptual nature underlie most of the problems identified by Cultural Evolution Society members. Guided by the heterogeneous 'grand challenges' emergent in this survey, this paper restates those challenges and adopts an organizational style requisite to discussion of them. The paper's goal is to contribute to increasing conceptual clarity and theoretical discernment around the most pressing challenges facing the field of cultural evolutionary science. It will be of most interest to cultural evolutionary scientists, theoreticians, philosophers of science and interdisciplinary researchers.

Social dynamics of vervet monkeys are dependent upon group identity

Traditions are widespread across the animal realm. Here, we investigated inter-group variability of social dynamics in wild vervet monkeys (Chlorocebus pygerythrus). We analyzed 84,704 social interactions involving 247 individuals collected over nine years in three neighboring groups of wild vervet monkeys. We found that in one group - Ankhase - individuals had a higher propensity to be affiliative (i.e., sociality) and grooming interactions were more reciprocal. Despite yearly fluctuations in sociality, differences between groups remained stable over time. Moreover, our statistical model predictions confirmed that these findings were maintained for similar sex ratios, age distributions, and group sizes. Strikingly, our results suggested that dispersing males adapted their sociality to the sociality of the group they integrated with. As a whole, our study sheds light on the existence of stable social dynamics dependent upon group identity in wild vervet monkeys and suggests that at least part of this variability is socially mediated.

Norm Dynamics: Interdisciplinary Perspectives on Social Norm Emergence, Persistence, and Change

Social norms are the glue that holds society together, yet our knowledge of them remains heavily intellectually siloed. This article provides an interdisciplinary review of the emerging field of norm dynamics by integrating research across the social sciences through a cultural-evolutionary lens. After reviewing key distinctions in theory and method, we discuss research on norm psychology-the neural and cognitive underpinnings of social norm learning and acquisition. We then overview how norms emerge and spread through intergenerational transmission, social networks, and group-level ecological and historical factors. Next, we discuss multilevel factors that lead norms to persist, change, or erode over time. We also consider cultural mismatches that can arise when a changing environment leads once-beneficial norms to become maladaptive. Finally, we discuss potential future research directions and the implications of norm dynamics for theory and policy.

Animal cognition and culture mediate predator-prey interactions

Predator-prey ecology and the study of animal cognition and culture have emerged as independent disciplines. Research combining these disciplines suggests that both animal cognition and culture can shape the outcomes of predator-prey interactions and their influence on ecosystems. We review the growing body of work that weaves animal cognition or culture into predator-prey ecology, and argue that both cognition and culture are significant but poorly understood mechanisms mediating how predators structure ecosystems. We present a framework exploring how previous experiences with the predation process creates feedback loops that alter the predation sequence. Cognitive and cultural predator-prey ecology offers ecologists new lenses through which to understand species interactions, their ecological consequences, and novel methods to conserve wildlife in a changing world.

Culturally determined interspecies communication between humans and honeyguides

Species interactions that vary across environments can create geographical mosaics of genetic coevolution. However, traits mediating species interactions are sometimes culturally inherited. Here we show that traditions of interspecies communication between people and wild birds vary in a culturally determined geographical mosaic. Honey hunters in different parts of Africa use different calls to communicate with greater honeyguides (Indicator indicator) that lead them to bees' nests. We show experimentally that honeyguides in Tanzania and Mozambique discriminate among honey hunters' calls, responding more readily to local than to foreign calls. This was not explained by variation in sound transmission and instead suggests that honeyguides learn local human signals. We discuss the forces stabilizing and diversifying interspecies communication traditions, and the potential for cultural coevolution between species.

Long-term memory of experienced jays facilitates problem-solving by naïve group members in the wild

Long-term memory affects animal fitness, especially in social species. In these species, the memory of group members facilitates the acquisition of novel foraging skills through social learning when naïve individuals observe and imitate the successful foraging behavior. Long-term memory and social learning also provide the framework for cultural behavior, a trait found in humans but very few other animal species. In birds, little is known about the duration of long-term memories for complex foraging skills, or the impact of long-term memory on group members. We tested whether wild jays remembered a complex foraging task more than 3 years after their initial experience and quantified the effect of this memory on naïve jay behavior. Experienced jays remembered how to solve the task and their behavior had significant positive effects on interactions by naïve group members at the task. This suggests that natural selection may favor long-term memory of solutions to foraging problems to facilitate the persistence of foraging skills that are specifically useful in the local environment in social birds with long lifespans and overlapping generations.

Overcoming bias in the comparison of human language and animal communication

Human language is a powerful communicative and cognitive tool. Scholars have long sought to characterize its uniqueness, but each time a property is proposed to set human language apart (e.g., reference, syntax), some (attenuated) version of that property is found in animals. Recently, the uniqueness argument has shifted from linguistic rules to cognitive capacities underlying them. Scholars argue that human language is unique because it relies on ostension and inference, while animal communication depends on simple associations and largely hardwired signals. Such characterizations are often borne out in published data, but these empirical findings are driven by radical differences in the ways animal and human communication are studied. The field of animal communication has been dramatically shaped by the "code model," which imagines communication as involving information packets that are encoded, transmitted, decoded, and interpreted. This framework standardized methods for studying meaning in animal signals, but it does not allow for the nuance, ambiguity, or contextual variation seen in humans. The code model is insidious. It is rarely referenced directly, but it significantly shapes how we study animals. To compare animal communication and human language, we must acknowledge biases resulting from the different theoretical models used. By incorporating new approaches that break away from searching for codes, we may find that animal communication and human language are characterized by differences of degree rather than kind.

Ponds as experimental arenas for studying animal movement: current research and future prospects

Animal movement is a multifaceted process that occurs for multiple reasons with powerful consequences for food web and ecosystem dynamics. New paradigms and technical innovations have recently pervaded the field, providing increasingly powerful means to deliver fine-scale movement data, attracting renewed interest. Specifically in the aquatic environment, tracking with acoustic telemetry now provides integral spatiotemporal information to follow individual movements in the wild. Yet, this technology also holds great promise for experimental studies, enhancing our ability to truly establish cause-and-effect relationships. Here, we argue that ponds with well-defined borders (i.e. "islands in a sea of land") are particularly well suited for this purpose. To support our argument, we also discuss recent experiences from studies conducted in an innovative experimental infrastructure, composed of replicated ponds equipped with modern aquatic telemetry systems that allow for unparalleled insights into the movement patterns of individual animals.

From real-time adaptation to social learning in robot ecosystems

While evolutionary robotics can create novel morphologies and controllers that are well-adapted to their environments, learning is still the most efficient way to adapt to changes that occur on shorter time scales. Learning proposals for evolving robots to date have focused on new individuals either learning a controller from scratch, or building on the experience of direct ancestors and/or robots with similar configurations. Here we propose and demonstrate a novel means for social learning of gait patterns, based on sensorimotor synchronization. Using movement patterns of other robots as input can drive nonlinear decentralized controllers such as CPGs into new limit cycles, hence encouraging diversity of movement patterns. Stable autonomous controllers can then be locked in, which we demonstrate using a quasi-Hebbian feedback scheme. We propose that in an ecosystem of robots evolving in a heterogeneous environment, such a scheme may allow for the emergence of generalist task-solvers from a population of specialists.

Emulative learning of a two-step task in free-ranging domestic pigs

Previous research showed that young domestic pigs learn through observation of conspecifics by using social learning mechanisms like social facilitation, enhancement effects, and even object movement re-enactment. The latter suggests some form of emulative learning in which the observer learns about the object's movements and affordances. As it remains unclear whether pigs need a social agent to learn about objects, we provided 36 free-ranging domestic pigs with varying degrees of social to non-social demonstrations on how to solve a two-step manipulative foraging task: observers watched either a conspecific or a human demonstrator, or self-moving objects ("ghost control"), or a ghost control accompanied by an inactive conspecific bystander. In addition, 22 subjects that were previously tested without any demonstrator were used as a non-observer control. To solve the task, the subjects had to first remove a plug from its recess to then be able to slide a cover to the side, which would lay open a food compartment. Observers interacted longer with the relevant objects (plugs) and were more successful in solving the task compared to non-observers. We found no differences with regard to success between the four observer groups, indicating that the pigs mainly learned about the apparatus rather than about the actions. As the only common feature of the different demonstrations was the movement of the plug and the cover, we conclude the observer pigs learned primarily by emulation, suggesting that social agents are not necessary for pigs when learning through observation.

Type-2 diabetes alters hippocampal neural oscillations and disrupts synchrony between hippocampus and cortex

Type 2 diabetes mellitus (T2DM) increases the risk of neurological diseases, yet how brain oscillations change as age and T2DM interact is not well characterized. To delineate the age and diabetic effect on neurophysiology, we recorded local field potentials with multichannel electrodes spanning the somatosensory cortex and hippocampus (HPC) under urethane anesthesia in diabetic and normoglycemic control mice, at 200 and 400 days of age. We analyzed the signal power of brain oscillations, brain state, sharp wave associate ripples (SPW-Rs), and functional connectivity between the cortex and HPC. We found that while both age and T2DM were correlated with a breakdown in long-range functional connectivity and reduced neurogenesis in the dentate gyrus and subventricular zone, T2DM further slowed brain oscillations and reduced theta-gamma coupling. Age and T2DM also prolonged the duration of SPW-Rs and increased gamma power during SPW-R phase. Our results have identified potential electrophysiological substrates of hippocampal changes associated with T2DM and age. The perturbed brain oscillation features and diminished neurogenesis may underlie T2DM-accelerated cognitive impairment.

Whole-genome long-read sequencing downsampling and its effect on variant calling precision and recall

Advances in long-read sequencing (LRS) technology continue to make whole-genome sequencing more complete, affordable, and accurate. LRS provides significant advantages over short-read sequencing approaches, including phased de novo genome assembly, access to previously excluded genomic regions, and discovery of more complex structural variants (SVs) associated with disease. Limitations remain with respect to cost, scalability, and platform-dependent read accuracy and the tradeoffs between sequence coverage and sensitivity of variant discovery are important experimental considerations for the application of LRS. We compare the genetic variant calling precision and recall of Oxford Nanopore Technologies (ONT) and PacBio HiFi platforms over a range of sequence coverages. For read-based applications, LRS sensitivity begins to plateau around 12-fold coverage with a majority of variants called with reasonable accuracy (F1 score above 0.5), and both platforms perform well for SV detection. Genome assembly increases variant calling precision and recall of SVs and indels in HiFi datasets with HiFi outperforming ONT in quality as measured by the F1 score of assembly-based variant callsets. While both technologies continue to evolve, our work offers guidance to design cost-effective experimental strategies that do not compromise on discovering novel biology.

Social learning mechanisms shape transmission pathways through replicate local social networks of wild birds

The emergence and spread of novel behaviours via social learning can lead to rapid population-level changes whereby the social connections between individuals shape information flow. However, behaviours can spread via different mechanisms and little is known about how information flow depends on the underlying learning rule individuals employ. Here, comparing four different learning mechanisms, we simulated behavioural spread on replicate empirical social networks of wild great tits and explored the relationship between individual sociality and the order of behavioural acquisition. Our results reveal that, for learning rules dependent on the sum and strength of social connections to informed individuals, social connectivity was related to the order of acquisition, with individuals with increased social connectivity and reduced social clustering adopting new behaviours faster. However, when behavioural adoption depends on the ratio of an individuals' social connections to informed versus uninformed individuals, social connectivity was not related to the order of acquisition. Finally, we show how specific learning mechanisms may limit behavioural spread within networks. These findings have important implications for understanding whether and how behaviours are likely to spread across social systems, the relationship between individuals' sociality and behavioural acquisition, and therefore for the costs and benefits of sociality.

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.

Flexible tool set transport in Goffin's cockatoos

The use of tool sets constitutes one of the most elaborate examples of animal technology, and reports of it in nature are limited to chimpanzees and Goffin's cockatoos. Although tool set use in Goffin's was only recently discovered, we know that chimpanzees flexibly transport tool sets, depending on their need. Flexible tool set transport can be considered full evidence for identification of a genuine tool set, as the selection of the second tool is not just a response to the outcomes of the use of the first tool but implies recognizing the need for both tools before using any of them (thus, categorizing both tools together as a tool set). In three controlled experiments, we tested captive Goffin's in tasks inspired by the termite fishing of Goualougo Triangle's chimpanzees. Thereby, we show that some Goffin's can innovate the use and flexibly use and transport a new tool set for immediate future use; therefore, their sequential tool use is more than the sum of its parts. VIDEO ABSTRACT.