Lewis G. Dean

Identification of the Social and Cognitive Processes Underlying Human Cumulative Culture

Acquire and Share Few would argue with the stance that human social cognition supports an unequaled capacity to acquire knowledge and to share it with others. Dean et al. (p. 1114; see the Perspective by Kurzban and Barrett) compared the extent to which these social and cognitive psychological processes can be elicited in children, capuchins, and chimpanzees through the use of a three-level puzzlebox task. Incentivized by improving rewards, 3- to 4-year-old children progressed from the first to the third level by imitating observed actions, taught other members of their social group how to solve the problem, and shared the rewards obtained. By contrast, neither the capuchins nor chimpanzees, very few of which ever reached the third level, exhibited these charactertistics. Humans not only watch and imitate each other but also learn from each other in multiple ways. The remarkable ecological and demographic success of humanity is largely attributed to our capacity for cumulative culture, with knowledge and technology accumulating over time, yet the social and cognitive capabilities that have enabled cumulative culture remain unclear. In a comparative study of sequential problem solving, we provided groups of capuchin monkeys, chimpanzees, and children with an experimental puzzlebox that could be solved in three stages to retrieve rewards of increasing desirability. The success of the children, but not of the chimpanzees or capuchins, in reaching higher-level solutions was strongly associated with a package of sociocognitive processes—including teaching through verbal instruction, imitation, and prosociality—that were observed only in the children and covaried with performance.

Human cumulative culture: A comparative perspective

Many animals exhibit social learning and behavioural traditions, but human culture exhibits unparalleled complexity and diversity, and is unambiguously cumulative in character. These similarities and differences have spawned a debate over whether animal traditions and human culture are reliant on homologous or analogous psychological processes. Human cumulative culture combines high‐fidelity transmission of cultural knowledge with beneficial modifications to generate a ‘ratcheting’ in technological complexity, leading to the development of traits far more complex than one individual could invent alone. Claims have been made for cumulative culture in several species of animals, including chimpanzees, orangutans and New Caledonian crows, but these remain contentious. Whilst initial work on the topic of cumulative culture was largely theoretical, employing mathematical methods developed by population biologists, in recent years researchers from a wide range of disciplines, including psychology, biology, economics, biological anthropology, linguistics and archaeology, have turned their attention to the experimental investigation of cumulative culture. We review this literature, highlighting advances made in understanding the underlying processes of cumulative culture and emphasising areas of agreement and disagreement amongst investigators in separate fields.

Sex ratio affects sex-specific innovation and learning in captive ruffed lemurs (Varecia variegata and Varecia rubra).

Recent years have witnessed extensive research into problem solving and innovation in primates, yet lemurs have not been subjected to the same level of attention as apes and monkeys, and the social context in which novel behavior appears has rarely been considered. We gave novel foraging puzzlebox devices to seven groups of ruffed lemurs (Varecia variegata and Varecia rubra) to examine the factors affecting rates of innovation and social learning. We found, across a range of group sex ratios, that animals of the less‐represented sex were more likely to contact and solve the puzzlebox sooner than those of the more‐represented sex. We established that while some individuals were able to solve the puzzleboxes there was no evidence of social learning. Our findings are consistent with previously reported male deference as a sexual strategy, but we conclude that the need for male deference diminishes when, within a group, males are rare. Am. J. Primatol. 73:1210–1221, 2011.

Innovation and social transmission in experimental micro-societies: Exploring the scope of cumulative culture in young children

The experimental study of cumulative culture and the innovations essential to it is a young science, with child studies so rare that the scope of cumulative cultural capacities in childhood remains largely unknown. Here we report a new experimental approach to the inherent complexity of these phenomena. Groups of 3–4-year-old children were presented with an elaborate array of challenges affording the potential cumulative development of a variety of techniques to gain increasingly attractive rewards. In contrast to a prior study, we found evidence for elementary forms of cumulative cultural progress, with inventions of solutions at lower levels spreading to become shared innovations, and some children then building on these to create more advanced but more rewarding innovations. This contrasted with markedly more constrained progress when children worked only by themselves, or if groups faced only the highest-level challenges from the start. Further experiments that introduced higher-level inventions via the inclusion of older children, or that created ecological change, with the easiest habitual solutions no longer possible, encouraged higher levels of cumulative innovation. Our results show children are not merely ‘cultural sponges’, but when acting in groups, display the beginnings of cycles of innovation and observational learning that sustain cumulative progress in problem solving. This article is part of the themed issue ‘Process and pattern in innovations from cells to societies’.

A Diverse and Flexible Teaching Toolkit Facilitates the Human Capacity for Cumulative Culture

Human culture is uniquely complex compared to other species. This complexity stems from the accumulation of culture over time through high- and low-fidelity transmission and innovation. One possible reason for why humans retain and create culture, is our ability to modulate teaching strategies in order to foster learning and innovation. We argue that teaching is more diverse, flexible, and complex in humans than in other species. This particular characteristic of human teaching rather than teaching itself is one of the reasons for human’s incredible capacity for cumulative culture. That is, humans unlike other species can signal to learners whether the information they are teaching can or cannot be modified. As a result teaching in humans can be used to support high or low fidelity transmission, innovation, and ultimately, cumulative culture.

Is it hot in here? Thermoregulation and homeostasis through an exercise activity

homeostasis, the control of an internal environment to maintain stable, relatively constant conditions, is a key concept in physiology ([1][1]). In endothermic species, including humans ( Homo sapiens ), the control of body temperature is fundamental to the control of a suitable internal environment

Chimpanzees demonstrate individual differences in social information use

Studies of transmission biases in social learning have greatly informed our understanding of how behaviour patterns may diffuse through animal populations, yet within-species inter-individual variation in social information use has received little attention and remains poorly understood. We have addressed this question by examining individual performances across multiple experiments with the same population of primates. We compiled a dataset spanning 16 social learning studies (26 experimental conditions) carried out at the same study site over a 12-year period, incorporating a total of 167 chimpanzees. We applied a binary scoring system to code each participant’s performance in each study according to whether they demonstrated evidence of using social information from conspecifics to solve the experimental task or not (Social Information Score—‘SIS’). Bayesian binomial mixed effects models were then used to estimate the extent to which individual differences influenced SIS, together with any effects of sex, rearing history, age, prior involvement in research and task type on SIS. An estimate of repeatability found that approximately half of the variance in SIS was accounted for by individual identity, indicating that individual differences play a critical role in the social learning behaviour of chimpanzees. According to the model that best fit the data, females were, depending on their rearing history, 15–24% more likely to use social information to solve experimental tasks than males. However, there was no strong evidence of an effect of age or research experience, and pedigree records indicated that SIS was not a strongly heritable trait. Our study offers a novel, transferable method for the study of individual differences in social learning.

Subjectivity may hinder the application of Kline's teaching framework in comparative contexts

We welcome Klines attempt to develop an overarching framework to allow much needed collaboration between fields in the study of teaching. While we see much utility in this enterprise, we are concerned that there is too much focus on the behavior of the teacher, without examining results or costs, and the categories within the framework are not sufficiently distinct.