Human Teaching and Cumulative Cultural Evolution

Conditions under which faithful cultural transmission through teaching promotes cumulative cultural evolution

It has been argued that teaching promotes the accurate transmission of cultural traits and eventually leads to cumulative cultural evolution (CCE). However, previous studies have questioned this argument. In this study, we modified the action sequences model into a network exploring model with reinforcement learning to examine the conditions under which teaching promotes CCE. Our model incorporates a time trade-off between innovation and teaching. Simulations revealed that the positive influence of teaching on CCE depends on task difficulty. When the task was too difficult and advanced, such that it could not be accomplished through individual learning within a limited time, spending more time on teaching-even at the expense of time for innovation-contributed to CCE. On the contrary, the easier the task, the more time was spent on innovation than on teaching, which contributed to the improvement of performance. These findings suggest that teaching becomes more valuable as cultures become more complex. Therefore, humanity must have co-evolved a complex cumulative culture and teaching that supports cultural fidelity.

The cultural evolution of teaching

Teaching is an important process of cultural transmission. Some have argued that human teaching is a cognitive instinct - a form of 'natural cognition' centred on mindreading, shaped by genetic evolution for the education of juveniles, and with a normative developmental trajectory driven by the unfolding of a genetically inherited predisposition to teach. Here, we argue instead that human teaching is a culturally evolved trait that exhibits characteristics of a cognitive gadget. Children learn to teach by participating in teaching interactions with socialising agents, which shape their own teaching practices. This process hijacks psychological mechanisms involved in prosociality and a range of domain-general cognitive abilities, such as reinforcement learning and executive function, but not a suite of cognitive adaptations specifically for teaching. Four lines of evidence converge on this hypothesis. The first, based on psychological experiments in industrialised societies, indicates that domain-general cognitive processes are important for teaching. The second and third lines, based on naturalistic and experimental research in small-scale societies, indicate marked cross-cultural variation in mature teaching practice and in the ontogeny of teaching among children. The fourth line indicates that teaching has been subject to cumulative cultural evolution, i.e. the gradual accumulation of functional changes across generations.

Teaching strategies are shaped by experience with formal education: Experimental evidence from caregiver-child dyads in two Tannese communities

Humans are extraordinary in the extent to which we rely on cumulative culture to act upon and make sense of our environment. Teaching is one social learning process thought to be fundamental to the evolution of cumulative culture as a means of adaptation in our species. However, the frequency of teaching and how we teach are known to vary across human sociocultural contexts. Understanding this variation adds to our understanding of the complex interplay between cognition and culture in shaping learning behavior but also contributes to theory around the costs and benefits of different social learning processes. Here, we examined how prior experience with formal education is related to the frequency and diversity of teaching behaviors in an experimental paradigm where caregivers were motivated (but not instructed) to teach a simple skill to a child (7-10 years old). We identified and coded a suite of subtle nonverbal behaviors that could be construed as facilitating learning. Dyads (n = 64) were recruited from two communities on Tanna Island that differ in their experience with formal schooling and their acceptance of Western institutions. We found evidence for parallel teaching strategies in both communities. However, the rate and diversity of teaching behaviors were positively associated with caregiver's experience with formal schooling and independently and negatively associated with being from a village that rejects Western-derived institutions. These results further our understanding of how multiple cultural processes influence social learning and highlights the powerful influence of formal schooling on the cultural evolution of teaching in humans.

Four-Year-Olds Share General Knowledge and Use Generic Language When Teaching

Young children's receptiveness to teaching is unquestioned, but their understanding of pedagogy has only begun to be explored. Two experiments (N = 90; 45 female) with 4-year-olds from racially and ethnically diverse backgrounds were conducted to test if they exchange general information and use generic language when teaching. Children in both experiments taught more general than episodic information and used more generic than episodic language when teaching. Experiment 2 showed that children did not prefer to report general information or use generic language in a non-pedagogical context. The findings suggest that by 4 years old, children understand that the goal of teaching is to transmit general knowledge.

Costly teaching contributes to the acquisition of spear hunting skill among BaYaka forager adolescents

Teaching likely evolved in humans to facilitate the faithful transmission of complex tasks. As the oldest evidenced hunting technology, spear hunting requires acquiring several complex physical and cognitive competencies. In this study, we used observational and interview data collected among BaYaka foragers (Republic of the Congo) to test the predictions that costlier teaching types would be observed at a greater frequency than less costly teaching in the domain of spear hunting and that teachers would calibrate their teaching to pupil skill level. To observe naturalistic teaching during spear hunting, we invited teacher-pupil groupings to spear hunt while wearing GoPro cameras. We analysed 68 h of footage totalling 519 teaching episodes. Most observed teaching events were costly. Direct instruction was the most frequently observed teaching type. Older pupils received less teaching and more opportunities to lead the spear hunt than their younger counterparts. Teachers did not appear to adjust their teaching to pupil experience, potentially because age was a more easily accessible heuristic for pupil skill than experience. Our study shows that costly teaching is frequently used to transmit complex tasks and that instruction may play a privileged role in the transmission of spear hunting knowledge.

Complex cognitive algorithms preserved by selective social learning in experimental populations

Many human abilities rely on cognitive algorithms discovered by previous generations. Cultural accumulation of innovative algorithms is hard to explain because complex concepts are difficult to pass on. We found that selective social learning preserved rare discoveries of exceptional algorithms in a large experimental simulation of cultural evolution. Participants (N = 3450) faced a difficult sequential decision problem (sorting an unknown sequence of numbers) and transmitted solutions across 12 generations in 20 populations. Several known sorting algorithms were discovered. Complex algorithms persisted when participants could choose who to learn from but frequently became extinct in populations lacking this selection process, converging on highly transmissible lower-performance algorithms. These results provide experimental evidence for hypothesized links between sociality and cognitive function in humans.

Children transition from simple associations to explicitly reasoned social learning strategies between age four and eight

To differentiate the use of simple associations from use of explicitly reasoned selective social learning, we can look for age-related changes in children’s behaviour that might signify a switch from one social learning strategy to the other. We presented 4- to 8-year-old children visiting a zoo in Scotland (N = 109) with a task in which the perceptual access of two informants was determined by the differing opacity of two screens of similar visual appearance during a hiding event. Initially success could be achieved by forming an association or inferring a rule based on salient visual (but causally irrelevant) cues. However, following a switch in the scenario, success required explicit reasoning about informants’ potential to provide valuable information based on their perceptual access. Following the switch, older children were more likely to select a knowledgeable informant. This suggests that some younger children who succeeded in the pre-switch trials had inferred rules or formed associations based on superficial, yet salient, visual cues, whereas older children made the link between perceptual access and the potential to inform. This late development and apparent cognitive challenge are consistent with proposals that such capacities are linked to the distinctiveness of human cumulative culture.

Shared intentionality, reason-giving and the evolution of human culture

The biological approach to culture focuses almost exclusively on processes of social learning, to the neglect of processes of cultural coordination including joint action and shared intentionality. In this paper, we argue that the distinctive features of human culture derive from humans' unique skills and motivations for coordinating with one another around different types of action and information. As different levels of these skills of 'shared intentionality' emerged over the last several hundred thousand years, human culture became characterized first by such things as collaborative activities and pedagogy based on cooperative communication, and then by such things as collaborative innovations and normatively structured pedagogy. As a kind of capstone of this trajectory, humans began to coordinate not just on joint actions and shared beliefs, but on the reasons for what we believe or how we act. Coordinating on reasons powered the kinds of extremely rapid innovation and stable cumulative cultural evolution especially characteristic of the human species in the last several tens of thousands of years. This article is part of a discussion meeting issue 'The emergence of collective knowledge and cumulative culture in animals, humans and machines'.

A cognitive-evolutionary model for the evolution of teaching

Mechanisms for social learning have rightly been the focus of much work in cultural evolution. But mechanisms for teaching-mechanisms that determine what information is available for learners to learn in the first place-are equally important to cultural evolution, especially in the case of humans. Here, we propose a simple model of teaching in the context of skill transmission. Our model derives the evolutionary cost and benefit of teaching by explicitly representing cognitive aspects of skill transmission as a dual-inheritance process. We then show that teaching cannot evolve when its direct cost is too high. We also show that there is an "explain-exploit" trade-off inherent to teaching: when payoffs from sharing information are not constant, there can be an indirect cost to teaching. This gives rise to an opportunity cost that goes beyond any direct cost that it may also entail. Finally, we show that evolution limits the strength of teaching provided that the direct cost of teaching is an increasing function of teaching effort. We then discuss how these factors might explain why teaching mechanisms are self-limiting, suggesting that such mechanisms may nevertheless play an important role in the evolution of cumulative culture in humans.

Orangutan mothers adjust their behaviour during food solicitations in a way that likely facilitates feeding skill acquisition in their offspring

Immature orangutans acquire their feeding skills over several years, via social and independent learning. So far, it has remained uninvestigated to what extent orangutan mothers are actively involved in this learning process. From a fitness point of view, it may be adaptive for mothers to facilitate their offspring’s skill acquisition to make them reach nutritional independence faster. Food solicitations are potential means to social learning which, because of their interactive nature, allow to investigate the degree of active involvement of the mother. To investigate the role of food solicitation and the role of the mother in immatures’ foraging skill acquisition, we analysed 1390 food solicitation events between 21 immature Sumatran orangutans (Pongo abelii) and their mothers, collected over 13 years at the Suaq Balimbing orangutan population. We found that solicitation rates decreased with increasing age of the immatures and increased with increasing processing complexity of the food item. Mothers were more likely to share complex items and showed the highest likelihoods of sharing around the age at which immatures are learning most of their feeding skills. Our results indicate that immature Sumatran orangutans use food solicitation to acquire feeding skills. Furthermore, mothers flexibly adjust their behaviour in a way that likely facilitates their offspring’s skill acquisition. We conclude that orangutan mothers have a more active role in the skill acquisition of their offspring than previously thought.

Technical reasoning is important for cumulative technological culture

Human technology has evolved in an unparalleled way, allowing us to expand across the globe. One fascinating question is, how do we understand the cognitive origins of this phenomenon, which is known as cumulative technological culture (CTC)? The dominant view posits that CTC results from our unique ability to learn from each other. The cultural niche hypothesis even minimizes the involvement of non-social cognitive skills in the emergence of CTC, claiming that technologies can be optimized without us understanding how they work, but simply through the retention of small improvements over generations. Here we conduct a partial replication of the experimental study of Derex et al. (Nature Human Behaviour, 2019) and show that the improvement of a physical system over generations is accompanied by an increased understanding of it. These findings indicate that technical-reasoning skills (non-social cognitive skills) are important in the acquisition, understanding and improvement of technical content-that is, specific to the technological form of cumulative culture-thereby making social learning a salient source of technical inspiration.

On the Neurocognitive Co-Evolution of Tool Behavior and Language: Insights from the Massive Redeployment Framework

Understanding the link between brain evolution and the evolution of distinctive features of modern human cognition is a fundamental challenge. A still unresolved question concerns the co-evolution of tool behavior (i.e., tool use or tool making) and language. The shared neurocognitive processes hypothesis suggests that the emergence of the combinatorial component of language skills within the frontal lobe/Broca's area made possible the complexification of tool-making skills. The importance of the frontal lobe/Broca's area in tool behavior is somewhat surprising with regard to the literature on neuropsychology and cognitive neuroscience, which has instead stressed the critical role of the left inferior parietal lobe. Therefore, to be complete, any version of the shared neurocognitive processes hypothesis needs to integrate the potential interactions between the frontal lobe/Broca's area and the left inferior parietal lobe as well as their co-evolution at a phylogenetic level. Here, we sought to provide the first elements of answer through the use of the massive deployment framework, which posits that evolutionarily older brain areas are deployed in more cognitive functions (i.e., they are less specific). We focused on the left parietal cortex, and particularly the left areas PF, PGI, and anterior intraparietal (AIP), which are known to be involved in tool use, language, and motor control, respectively. The deployment of each brain area in different cognitive functions was measured by conducting a meta-analysis of neuroimaging studies. Our results confirmed the pattern of specificity for each brain area and also showed that the left area PGI was far less specific than the left areas PF and AIP. From these findings, we discuss the different evolutionary scenarios depicting the potential co-evolution of the combinatorial and generative components of language and tool behavior in our lineage.

Development of strategic social information seeking: Implications for cumulative culture

Human learners are rarely the passive recipients of valuable social information. Rather, learners usually have to actively seek out information from a variety of potential others to determine who is in a position to provide useful information. Yet, the majority of developmental social learning paradigms do not address participants’ ability to seek out information for themselves. To investigate age-related changes in children’s ability to seek out appropriate social information, 3- to 8-year-olds (N = 218) were presented with a task requiring them to identify which of four possible demonstrators could provide critical information for unlocking a box. Appropriate information seeking improved significantly with age. The particularly high performance of 7- and 8-year-olds was consistent with the expectation that older children’s increased metacognitive understanding would allow them to identify appropriate information sources. Appropriate social information seeking may have been overlooked as a significant cognitive challenge involved in fully benefiting from others’ knowledge, potentially influencing understanding of the phylogenetic distribution of cumulative culture.

Prestige and content biases together shape the cultural transmission of narratives

Cultural transmission biases such as prestige are thought to have been a primary driver in shaping the dynamics of human cultural evolution. However, few empirical studies have measured the importance of prestige relative to other effects, such as content biases present within the information being transmitted. Here, we report the findings of an experimental transmission study designed to compare the simultaneous effects of a model using a high- or low-prestige regional accent with the presence of narrative content containing social, survival, emotional, moral, rational, or counterintuitive information in the form of a creation story. Results from multimodel inference reveal that prestige is a significant factor in determining the salience and recall of information, but that several content biases, specifically social, survival, negative emotional, and biological counterintuitive information, are significantly more influential. Further, we find evidence that reliance on prestige cues may serve as a conditional learning strategy when no content cues are available. Our results demonstrate that content biases serve a vital and underappreciated role in cultural transmission and cultural evolution. Social media summary: Storyteller and tale are both key to memorability, but some content is more important than the storyteller's prestige.

The Life History of Learning Subsistence Skills among Hadza and BaYaka Foragers from Tanzania and the Republic of Congo

Aspects of human life history and cognition, such as our long childhoods and extensive use of teaching, theoretically evolved to facilitate the acquisition of complex tasks. The present paper empirically examines the relationship between subsistence task difficulty and age of acquisition, rates of teaching, and rates of oblique transmission among Hadza and BaYaka foragers from Tanzania and the Republic of Congo. We further examine cross-cultural variation in how and from whom learning occurred. Learning patterns and community perceptions of task difficulty were assessed through interviews. We found no relationship between task difficulty, age of acquisition, and oblique transmission, and a weak but positive relationship between task difficulty and rates of teaching. While same-sex transmission was normative in both societies, tasks ranked as more difficult were more likely to be transmitted by men among the BaYaka, but not among the Hadza, potentially reflecting cross-cultural differences in the sexual division of subsistence and teaching labor. Further, the BaYaka were more likely to report learning via teaching, and less likely to report learning via observation, than the Hadza, possibly owing to differences in socialization practices.

Cognitive prerequisites for cumulative culture are context-dependent: Children's potential for ratcheting depends on cue longevity

Human cumulative culture has been suggested to depend on human-unique cognitive mechanisms, explaining its apparent absence in other species. We show that the potential for exhibiting cumulative culture depends on the cognitive abilities of the agents and the demands associated with using information generated by others' activity. 154 children aged 3-6 years played a searching game ("Find the Treasure"), taking their turn after a puppet demonstrator. The puppet's attempt revealed information about the contents of the locations searched, which could be exploited to target rewarded locations, and avoid unrewarded ones. Two conditions were presented, intended to capture realistic variation in the transience of the cues generated by another individual's activity. In one condition, the puppet's demonstration provided transient information - boxes were opened, seen to be rewarded or not, and then closed. In the other condition the puppet's chosen boxes remained partially open, providing an enduring visible cue as to whether that location was rewarded. Children undertook three trials of varying demonstration success, and we used patterns of performance to infer the potential for improvement over multiple generations of transmission. In the Enduring Cues condition, children's performance demonstrated the potential for cumulative culture. In contrast, in the Transient Information condition, only older children showed improved performances following higher success demonstrations and overall performance was not compatible with the possibility of improvements over generations of social transmission. We conclude that under certain conditions cumulative culture could occur in many species, but in a broader range of contexts in humans.

The Pedagogue, the Engineer, and the Friend : From Whom Do We Learn?

Humans can follow different social learning strategies, sometimes oriented toward the models' characteristics (i.e., who-strategies). The goal of the present study was to explore which who-strategy is preferentially followed in the technological context based on the models' psychological characteristics. We identified three potential who-strategies: Copy the pedagogue (a model with high theory-of-mind skills), copy the engineer (a model with high technical-reasoning skills), and copy the friend (a model with high level of prosocialness). We developed a closed-group micro-society paradigm in which participants had to build the highest possible towers. Participants began with an individual building phase. Then, they were gathered to discuss the best solutions to increase tower height. After this discussion phase, they had to make a new building attempt, followed by another discussion phase, and so forth for a total of six building phases and five discussion rounds. This methodology allowed us to create an attraction score for each participant (the more an individual was copied in a group, the greater the attraction score). We also assessed participants' theory-of-mind skills, technical-reasoning skills, and prosocialness to predict participants' attraction scores based on these measures. Results show that we learn from engineers (high technical-reasoning skills) because they are the most successful. Their attraction power is not immediate, but after they have been identified as attractors, their technique is copied irrespective of their pedagogy (theory-of-mind skills) or friendliness (prosocialness). These findings open avenues for the study of the cognitive bases of human technological culture.

The value of teaching increases with tool complexity in cumulative cultural evolution

Human cumulative cultural evolution (CCE) is recognized as a powerful ecological and evolutionary force, but its origins are poorly understood. The long-standing view that CCE requires specialized social learning processes such as teaching has recently come under question, and cannot explain why such processes evolved in the first place. An alternative, but largely untested, hypothesis is that these processes gradually coevolved with an increasing reliance on complex tools. To address this, we used large-scale transmission chain experiments (624 participants), to examine the role of different learning processes in generating cumulative improvements in two tool types of differing complexity. Both tool types increased in efficacy across experimental generations, but teaching only provided an advantage for the more complex tools. Moreover, while the simple tools tended to converge on a common design, the more complex tools maintained a diversity of designs. These findings indicate that the emergence of cumulative culture is not strictly dependent on, but may generate selection for, teaching. As reliance on increasingly complex tools grew, so too would selection for teaching, facilitating the increasingly open-ended evolution of cultural artefacts.

The value of teaching increases with tool complexity in cumulative cultural evolution

Human cumulative cultural evolution (CCE) is recognized as a powerful ecological and evolutionary force, but its origins are poorly understood. The long-standing view that CCE requires specialized social learning processes such as teaching has recently come under question, and cannot explain why such processes evolved in the first place. An alternative, but largely untested, hypothesis is that these processes gradually coevolved with an increasing reliance on complex tools. To address this, we used large-scale transmission chain experiments (624 participants), to examine the role of different learning processes in generating cumulative improvements in two tool types of differing complexity. Both tool types increased in efficacy across experimental generations, but teaching only provided an advantage for the more complex tools. Moreover, while the simple tools tended to converge on a common design, the more complex tools maintained a diversity of designs. These findings indicate that the emergence of cumulative culture is not strictly dependent on, but may generate selection for, teaching. As reliance on increasingly complex tools grew, so too would selection for teaching, facilitating the increasingly open-ended evolution of cultural artefacts.

Inferring Behavior From Partial Social Information Plays Little or No Role in the Cultural Transmission of Adaptive Traits

Many human cultural traits become increasingly beneficial as they are repeatedly transmitted, thanks to an accumulation of modifications made by successive generations. But how do later generations typically avoid modifications which revert traits to less beneficial forms already sampled and rejected by earlier generations? And how can later generations do so without direct exposure to their predecessors' behavior? One possibility is that learners are sensitive to cues of non-random production in others' behavior, and that particular variants (e.g., those containing structural regularities unlikely to occur spontaneously) have been produced deliberately and with some effort. If this non-random behavior is attributed to an informed strategy, then the learner may infer that apparent avoidance of certain possibilities indicates that these have already been sampled and rejected. This could potentially prevent performance plateaus resulting from learners modifying inherited behaviors randomly. We test this hypothesis in four experiments in which participants, either individually or in interacting dyads, attempt to locate rewards in a search grid, guided by partial information about another individual's experience of the task. We find that in some contexts, valid inferences about another's behavior can be made from partial information, and these inferences can be used in a way which facilitates trait adaptation. However, the benefit of these inferences appears to be limited, and in many contexts-including some which have the potential to make inferring the experience of another individual easier-there appears to be no benefit at all. We suggest that inferring previous behavior from partial social information plays a minimal role in the adaptation of cultural traits.

Supporting the weight of the elephant in the room: Technical intelligence propped up by social cognition and language

We consider the evolutionary plausibility of Osiurak and Reynaud's (O&R) arguments. We argue that technical reasoning is not quite the magic bullet that O&R assume, and instead propose a co-evolutionary account of the interplay between technical reasoning and social learning, with language emerging as a vital issue neglected in O&R's account.

The evolution of high-fidelity social learning

A defining feature of human culture is that knowledge and technology continually improve over time. Such cumulative cultural evolution (CCE) probably depends far more heavily on how reliably information is preserved than on how efficiently it is refined. Therefore, one possible reason that CCE appears diminished or absent in other species is that it requires accurate but specialized forms of social learning at which humans are uniquely adept. Here, we develop a Bayesian model to contrast the evolution of high-fidelity social learning, which supports CCE, against low-fidelity social learning, which does not. We find that high-fidelity transmission evolves when (1) social and (2) individual learning are inexpensive, (3) traits are complex, (4) individual learning is abundant, (5) adaptive problems are difficult and (6) behaviour is flexible. Low-fidelity transmission differs in many respects. It not only evolves when (2) individual learning is costly and (4) infrequent but also proves more robust when (3) traits are simple and (5) adaptive problems are easy. If conditions favouring the evolution of high-fidelity transmission are stricter (3 and 5) or harder to meet (2 and 4), this could explain why social learning is common, but CCE is rare.

Technition: When Tools Come Out of the Closet

People are ambivalently enthusiastic and anxious about how far technology can go. Therefore, understanding the neurocognitive bases of the human technical mind should be a major topic of the cognitive sciences. Surprisingly, however, scientists are not interested in this topic or address it only marginally in other mainstream domains (e.g., motor control, action observation, social cognition). In fact, this lack of interest may hinder our understanding of the necessary neurocognitive skills underlying our appetence for transforming our physical environment. Here, we develop the thesis that our technical mind originates in perhaps uniquely human neurocognitive skills, namely, technical-reasoning skills involving the area PF within the left inferior parietal lobe. This thesis creates an epistemological rupture with the state of the art that justifies the emergence of a new field in the cognitive sciences (i.e., technition) dedicated to the intelligence hidden behind tools and other forms of technologies, including constructions.

Roles of Technical Reasoning, Theory of Mind, Creativity, and Fluid Cognition in Cumulative Technological Culture

Cumulative technological culture can be defined as the progressive diversification, complexification, and enhancement of technological traits through generations. An outstanding issue is to specify the cognitive bases of this phenomenon. Based on the literature, we identified four potential cognitive factors: namely, theory-of-mind, technical-reasoning, creativity, and fluid-cognitive skills. The goal of the present study was to test which of these factors-or a combination thereof-best predicted the cumulative performance in two experimental, micro-society conditions (Communication and Observation conditions; n = 100 each) differing in the nature of the interaction (verbal, visual) allowed between participants. The task was to build the highest possible tower. Participants were also assessed on the four aforementioned cognitive factors in order to predict cumulative performance (tower height) and attractiveness. Our findings indicate that technical-reasoning skills are the best predictor of cumulative performance (tower height), even if their role may be restricted to the specific technological domain. Theory-of-mind skills may have a facilitator role, particularly in the Communication condition. Creativity can also help in the generation of novel ideas, but it is not sufficient to support innovation. Finally, fluid cognition is not involved in cumulative technological culture. Taken together, these findings suggest that domain-specific knowledge (i.e., technical-reasoning skills) remains critical for explaining cumulative technological culture.

Two-year-old children preferentially transmit simple actions but not pedagogically demonstrated actions

Children are sensitive to both social and non-social aspects of the learning environment. Among social cues, pedagogical communication has been shown to not only play a role in children's learning, but also in their own active transmission of knowledge. Vredenburgh, Kushnir and Casasola, Developmental Science, 2015, 18, 645 showed that 2-year-olds are more likely to demonstrate an action to a naive adult after learning it in a pedagogical than in a non-pedagogical context. This finding was interpreted as evidence that pedagogically transmitted information has a special status as culturally relevant. Here we test the limits of this claim by setting it in contrast with an explanation in which the relevance of information is the outcome of multiple interacting social (e.g., pedagogical demonstration) and non-social properties (e.g., action complexity). To test these competing hypotheses, we varied both pedagogical cues and action complexity in an information transmission paradigm with 2-year-old children. In Experiment 1, children preferentially transmitted simple non-pedagogically demonstrated actions over pedagogically demonstrated more complex actions. In Experiment 2, when both actions were matched for complexity, we found no evidence of preferential transmission of pedagogically demonstrated actions. We discuss possible reasons for the discrepancy between our results and previous literature showing an effect of pedagogical cues on cultural transmission, and conclude that our results are compatible with the view that pedagogical and other cues interact, but incompatible with the theory of a privileged role for pedagogical cues.

The elephant in the room: What matters cognitively in cumulative technological culture

Cumulative technological culture (CTC) refers to the increase in the efficiency and complexity of tools and techniques in human populations over generations. A fascinating question is to understand the cognitive origins of this phenomenon. Because CTC is definitely a social phenomenon, most accounts have suggested a series of cognitive mechanisms oriented toward the social dimension (e.g., teaching, imitation, theory of mind, and metacognition), thereby minimizing the technical dimension and the potential influence of non-social, cognitive skills. What if we have failed to see the elephant in the room? What if social cognitive mechanisms were only catalyzing factors and not the sufficient and necessary conditions for the emergence of CTC? In this article, we offer an alternative, unified cognitive approach to this phenomenon by assuming that CTC originates in non-social cognitive skills, namely technical-reasoning skills which enable humans to develop the technical potential necessary to constantly acquire and improve technical information. This leads us to discuss how theory of mind and metacognition, in concert with technical reasoning, can help boost CTC. The cognitive approach developed here opens up promising new avenues for reinterpreting classical issues (e.g., innovation, emulation vs. imitation, social vs. asocial learning, cooperation, teaching, and overimitation) in a field that has so far been largely dominated by other disciplines, such as evolutionary biology, mathematics, anthropology, archeology, economics, and philosophy.

Cultural transmission in a food preparation task: The role of interactivity, innovation and storytelling

Interactive conversation drives the transmission of cultural information in small groups and large networks. In formal (e.g. schools) and informal (e.g. home) learning settings, interactivity does not only allow individuals and groups to faithfully transmit and learn new knowledge and skills, but also to boost cumulative cultural evolution. Here we investigate how interactivity affects performance, teaching, learning, innovation and chosen diffusion mode (e.g. instructional discourse vs. storytelling) of previously acquired information in a transmission chain experiment. In our experiment, participants (n = 288) working in 48 chains with three generations of pairs had to learn and complete a collaborative food preparation task (ravioli-making), and then transmit their experience to a new generation of participants in an interactive and non-interactive condition. Food preparation is a real-world task that it is taught and learned across cultures and transmitted over generations in families and groups. Pairs were defined as teachers or learners depending on their role in the transmission chain. The number of good exemplars of ravioli each pair produced was taken as measurement of performance. Contrary to our expectations, the results did not reveal that (1) performance increased over generations or that (2) interactivity in transmission sessions promoted increased performance. However, the results showed that (3) interactivity promoted the transmission of more information from teachers to learners; (4) increased quantity of information transmission from teachers led to higher performance in learners; (5) higher performance generations introduced more innovations in transmission sessions; (6) learners applied those transmitted innovations to their performance which made them persist over generations; (7) storytelling was specialized for the transmission of non-routine, unexpected information. Our findings offer new insights on how interactivity, innovation and storytelling affect the cultural transmission of complex collaborative tasks.

Prestige and dominance-based hierarchies exist in naturally occurring human groups, but are unrelated to task-specific knowledge

Prestige and dominance are thought to be two evolutionarily distinct routes to gaining status and influence in human social hierarchies. Prestige is attained by having specialist knowledge or skills that others wish to learn, whereas dominant individuals use threat or fear to gain influence over others. Previous studies with groups of unacquainted students have found prestige and dominance to be two independent avenues of gaining influence within groups. We tested whether this result extends to naturally occurring social groups. We ran an experiment with 30 groups of people from Cornwall, UK (n = 150). Participants answered general knowledge questions individually and as a group, and subsequently nominated a representative to answer bonus questions on behalf of the team. Participants then anonymously rated all other team-mates on scales of prestige, dominance, likeability and influence on the task. Using a model comparison approach with Bayesian multi-level models, we found that prestige and dominance ratings were predicted by influence ratings on the task, replicating previous studies. However, prestige and dominance ratings did not predict who was nominated as team representative. Instead, participants nominated team members with the highest individual quiz scores, despite this information being unavailable to them. Interestingly, team members who were initially rated as being high status in the group, such as a team captain or group administrator, had higher ratings of both dominance and prestige than other group members. In contrast, those who were initially rated as someone from whom others would like to learn had higher prestige, but not higher dominance, supporting the claim that prestige reflects social learning opportunities. Our results suggest that prestige and dominance hierarchies do exist in naturally occurring social groups, but that these hierarchies may be more domain-specific and less flexible than we anticipated.

Replication and emergence in cultural transmission

Humans are fundamentally defined by our socially transmitted, often long-lived, sophisticated cultural traits. The nature of cultural transmission is the subject of ongoing debate: while some emphasize that it is a biased, transformational process, others point out that high-fidelity transmission is required to explain the quintessentially cumulative nature of human culture. This paper integrates both views into a model that has two main components: First, actions - observable motor-behavioural patterns - are inherited with high fidelity, or replicated, when they are copied, largely independently of their normal, effective or conventional function, by naive learners. Replicative action copying is the unbiased transmission process that ensures the continuity of cultural traditions. Second, mental culture - knowledge, skills, attitudes and values - is not inherited directly or faithfully, but instead emerges, or develops, during usage, when individuals learn the associations between actions and their contexts and outcomes. Mental cultural traits remain stable over generations to the extent that they are informed by similar (replicated) motor patterns unfolding in similar environments. The arguments in support of this model rest on clear distinctions between inheritance and usage; between public-behavioural and private-mental culture; and between selection for fidelity and selection for function.

Using Experimental Research Designs to Explore the Scope of Cumulative Culture in Humans and Other Animals

In humans, cultural evolutionary processes are capable of shaping our cognition, because the conceptual tools we learn from others enable mental feats which otherwise would be beyond our capabilities. This is possible because human culture supports the intergenerational accumulation of skills and knowledge, such that later generations can benefit from the experience and exploration efforts of their predecessors. However, it remains unclear how exactly human social transmission supports the accumulation of advantageous traits, and why we see little evidence of this in the natural behavior of other species. Thus, it is difficult to know whether the cognitive abilities of other animals might be similarly scaffolded by processes of cultural evolution. In this article, I discuss how experimental studies of cultural evolution have contributed to our understanding of human cumulative culture, as well as some of the limitations of these approaches. I also discuss how similar research designs can be used to evaluate the potential for cumulative culture in other species. Such research may be able to clarify what distinguishes human cumulative culture from related phenomena in nonhumans, shedding light on the issue of whether other species also have the potential to develop cognitive capacities that are outcomes of cultural evolution.

Culture drives cognitive evolution by supporting the transmission and intergenerational accumulation of skills and knowledge, based on social learning and teaching: Later generations benefit from what their predecessors acquired. Taking a metaperspective on those experimental studies that explore the mechanisms underlying cultural transmission, Caldwell discusses their potential for generating valuable insights, their possible limitations, and their generalizability to other species.

Storytelling as Adaptive Collective Sensemaking

Storytelling represents a key element in the creation and propagation of culture. Three main accounts of the adaptive function of storytelling include (a) manipulating the behavior of the audience to enhance the fitness of the narrator, (b) transmitting survival‐relevant information while avoiding the costs involved in the first‐hand acquisition of that information, and (c) maintaining social bonds or group‐level cooperation. We assess the substantial evidence collected in experimental and ethnographic studies for each account. These accounts do not always appeal to the specific features of storytelling above and beyond language use in general. We propose that the specific adaptive value of storytelling lies in making sense of non‐routine, uncertain, or novel situations, thereby enabling the collaborative development of previously acquired skills and knowledge, but also promoting social cohesion by strengthening intragroup identity and clarifying intergroup relations.

Bietti, Tilston and Bangerter take an evolutionary approach towards memory transmission and storytelling, arguing that storytelling plays a central role in the creation and transmission of cultural information. They suggest that storytelling is a vehicle to transmit survival‐related information that helps to avoid the costs involved in the first‐hand acquisition of that information and contributes to the maintenance of social bonds and group‐level cooperation. Furthermore, Bietti et al. argue that, going beyond storytelling’s individualist role of manipulating the audience to enhance fitness of the narrator, that these adaptive functions of storytelling may well be assigned to other forms of language use besides narration (e.g., instructional discourse and argumentation). Based on this evidence, Bietti and colleagues claim that the specific adaptive function of storytelling lies in making sense of non‐routine, uncertain, or novel situations, thereby enabling collective sensemaking.