Testing differential use of payoff-biased social learning strategies in children and chimpanzees

Various non-human animal species have been shown to exhibit behavioural traditions. Importantly, this research has been guided by what we know of human culture, and the question of whether animal cultures may be homologous or analogous to our own culture. In this paper, we assess whether models of human cultural transmission are relevant to understanding biological fundamentals by investigating whether accounts of human payoff-biased social learning are relevant to chimpanzees (Pan troglodytes). We submitted 4- and 5-year-old children (N = 90) and captive chimpanzees (N = 69) to a token–reward exchange task. The results revealed different forms of payoff-biased learning across species and contexts. Specifically, following personal and social exposure to different tokens, children's exchange behaviour was consistent with proportional imitation, where choice is affected by both prior personally acquired and socially demonstrated token–reward information. However, when the socially derived information regarding token value was novel, children's behaviour was consistent with proportional observation; paying attention to socially derived information and ignoring their prior personal experience. By contrast, chimpanzees' token choice was governed by their own prior experience only, with no effect of social demonstration on token choice, conforming to proportional reservation. We also find evidence for individual- and group-level differences in behaviour in both species. Despite the difference in payoff strategies used, both chimpanzees and children adopted beneficial traits when available. However, the strategies of the children are expected to be the most beneficial in promoting flexible behaviour by enabling existing behaviours to be updated or replaced with new and often superior ones

The development and validation of a scoring tool to predict the operative duration of elective laparoscopic cholecystectomy

Background: The ability to accurately predict operative duration has the potential to optimise theatre efficiency and utilisation, thus reducing costs and increasing staff and patient satisfaction. With laparoscopic cholecystectomy being one of the most commonly performed procedures worldwide, a tool to predict operative duration could be extremely beneficial to healthcare organisations. Methods: Data collected from the CholeS study on patients undergoing cholecystectomy in UK and Irish hospitals between 04/2014 and 05/2014 were used to study operative duration. A multivariable binary logistic regression model was produced in order to identify significant independent predictors of long (> 90 min) operations. The resulting model was converted to a risk score, which was subsequently validated on second cohort of patients using ROC curves. Results: After exclusions, data were available for 7227 patients in the derivation (CholeS) cohort. The median operative duration was 60 min (interquartile range 45–85), with 17.7% of operations lasting longer than 90 min. Ten factors were found to be significant independent predictors of operative durations > 90 min, including ASA, age, previous surgical admissions, BMI, gallbladder wall thickness and CBD diameter. A risk score was then produced from these factors, and applied to a cohort of 2405 patients from a tertiary centre for external validation. This returned an area under the ROC curve of 0.708 (SE = 0.013, p  90 min increasing more than eightfold from 5.1 to 41.8% in the extremes of the score. Conclusion: The scoring tool produced in this study was found to be significantly predictive of long operative durations on validation in an external cohort. As such, the tool may have the potential to enable organisations to better organise theatre lists and deliver greater efficiencies in care

The James Webb Space Telescope Mission

Twenty-six years ago a small committee report, building on earlier studies, expounded a compelling and poetic vision for the future of astronomy, calling for an infrared-optimized space telescope with an aperture of at least $4m$. With the support of their governments in the US, Europe, and Canada, 20,000 people realized that vision as the $6.5m$ James Webb Space Telescope. A generation of astronomers will celebrate their accomplishments for the life of the mission, potentially as long as 20 years, and beyond. This report and the scientific discoveries that follow are extended thank-you notes to the 20,000 team members. The telescope is working perfectly, with much better image quality than expected. In this and accompanying papers, we give a brief history, describe the observatory, outline its objectives and current observing program, and discuss the inventions and people who made it possible. We cite detailed reports on the design and the measured performance on orbit.Comment: Accepted by PASP for the special issue on The James Webb Space Telescope Overview, 29 pages, 4 figure

Quantifying and Modelling Social Learning Processes in Monkey Populations

Putative traditions in animal populations remain unsubstantiated in the absence of methods to isolate the mechanisms of social transmission in social groups. Here we address this problem by quantifying the effect of two social learning processes, namely stimulus enhancement and observational learning, on the adoption of a novel extractive foraging behavior in groups of callitrichid monkeys. We simulate the effect of these processes in a model for the spread of a novel behaviour and also select which model-parameters provide the best fit to the monkey data. Our analysis reveals evidence for asocial processes and stimulus enhancement but not observational learning. The latency to solve the tasks co-varied with the strength of the asocial, but not social, processes. Further, only asocial parameters were required for the model to fit the data. Both model and monkey diffusion data exhibited deceleratory diffusion curves. We discuss the relationship between both the asocial and social processes and the diffusion dynamics.La existencia de supuestas tradiciones en las poblaciones animales sigue sin resolverse en ausencia de métodos que permitan aislar los mecanismos de transmisión social en los grupos sociales. Aquí tratamos este problema mediante la cuantificación del efecto que jugaron dos procesos de aprendizaje social, el realce del estímulo y el aprendizaje observacional, en la adopción de un comportamiento novedoso de recolección en grupos de monos de la familia Callitrichidae. Simulamos el efecto de estos procesos en un modelo de cara a explicar la extensión de un comportamiento novedoso y para seleccionar que parámetros del modelo proporcionaban el mejor ajuste a los datos del mono. Nuestro análisis revela evidencias para los procesos asociales y el realce estimular, pero no para aprendizaje observacional. Las latencias empleadas en la solución de las tareas covarió con la fuerza de los procesos asociales, pero no con la de los procesos sociales. Más aún, el modelo solo requirió los parámetros de los factores no sociales para ajustar los datos. El modelo y los datos de difusión mostraron ambos curvas desaceleradas de difusión. Finalmente, discutimos la relación entre los procesos asociales y sociales y la dinámica de la difusión cultural

Target Article with Commentaries: Developmental niche construction

Niche construction is the modification of components of the environment through an organism's activities. Humans modify their environments mainly through ontogenetic and cultural processes, and it is this reliance on learning, plasticity and culture that lends human niche construction a special potency. In this paper we aim to facilitate discussion between researchers interested in niche construction and those interested in human cognitive development by highlighting some of the related processes. We discuss the transmission of culturally relevant information, how the human mind is a symbol-generating and artefact-devising system, and how these processes are bi-directional, with infants and children both being directed, and directing, their own development. We reflect on these in the light of four approaches: natural pedagogy, activity theory, distributed cognition and situated learning. Throughout, we highlight pertinent examples in non-humans that parallel or further explicate the processes discussed. Finally we offer three future directions; two involving the use of new techniques in the realms of neuroscience and modelling, and the third suggesting exploration of changes in the effects of niche construction across the lifespan.</p

Unknotting the interactive effects of learning processes on cultural evolutionary dynamics

Forms of non-random copying error provide sources of inherited variation yet their effects on cultural evolutionary dynamics are poorly understood. Focusing on variation in granny and reef knot forms, we present a mathematical model that specifies how these variant frequencies are affected by non-linear interactions between copying fidelity, mirroring, handedness and repetition biases. Experiments on adult humans allowed these effects to be estimated using Approximate Bayesian Computation and the model is iterated to explain the prevalence of granny over reef knots in the wild. Our study system also serves to show conditions under which copying fidelity drives heterogeneity in cultural variants at equilibrium, and that interaction between unbiased forms of copying error can skew cultural variation