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.

Sequential recall of meaningful and arbitrary sequences by orangutans and human children: Does content matter?

Do visual cues such as size, color, and number facilitate sequential recall in orangutans and human children? In Experiment 1, children and adult orangutans solved two types of sequences, arbitrary (unrelated pictures) and meaningful (pictures varied along a spectrum according to the size, color, or number of items shown), in a touchscreen paradigm. It was found that visual cues did not increase the percentage of correct responses for either children or orangutans. In order to demonstrate that the failure to spontaneously seriate along these dimensions was not due to a general inability to perceive the dimensions nor to an inability to seriate items, in Experiment 2, orangutans were trained on one type of sequence and tested on novel sequences organized according to the same rule (i.e., pictures varied on the number spectrum only). The orangutans performed significantly better on novel meaningful sequences in this task than on novel arbitrary sequences. These results indicate that, while orangutans and human children share the ability to learn how to order items according to their size, color, or number, both orangutans and humans lack a cognitive propensity to spontaneously (i.e., without prior training or enculturation) order multiple items by size, color, or number.

The evolution of coordination: a phylogenetic meta-analysis and systematic review.

To solve many cooperative problems, humans must have evolved the ability to solve physical problems in their environment by coordinating their actions. There have been many studies conducted across multiple different species regarding coordinating abilities. These studies aim to provide data which will help illuminate the evolutionary origins of cooperative problem solving and coordination. However, it is impossible to make firm conclusions about the evolutionary origins of coordinating abilities without a thorough comparative analysis of the existing data. Furthermore, there may be certain aspects of the literature that make it very difficult to confidently address evolutionary and meta-analytic questions. This study aimed to rectify this by using meta-analysis, phylogenetic analysis and systematic review to analyse the data already obtained across multiple studies, and to assess the reliability of this data. We found that many studies did not provide the information necessary for meta-analysis, or were not comparable enough to other studies to be included in analyses, meaning meta-analyses were underpowered or could not be conducted due to low samples of both studies and different species. Overall, we found that many studies reported small positive effects across studies, but the standard errors of these effects frequently traversed zero.

A potent effect of observational learning on chimpanzee tool construction.

Although tool use occurs in diverse species, its complexity may mark an important distinction between humans and other animals. Chimpanzee tool use has many similarities to that seen in humans, yet evidence of the cumulatively complex and constructive technologies common in human populations remains absent in free-ranging chimpanzees. Here we provide the first evidence that chimpanzees have a latent capacity to socially learn to construct a composite tool. Fifty chimpanzees were assigned to one of five demonstration conditions that varied in the amount and type of information available in video footage of a conspecific. Chimpanzees exposed to complete footage of a chimpanzee combining the two components to retrieve a reward learned to combine the tools significantly more than those exposed to more restricted information. In a follow-up test, chimpanzees that constructed tools after watching the complete demonstration tended to do so even when the reward was within reach of the unmodified components, whereas those that spontaneously solved the task (without seeing the modification process) combined only when necessary. Social learning, therefore, had a powerful effect in instilling a marked persistence in the use of a complex technique at the cost of efficiency, inhibiting insightful tool use.

An unusual presentation of acute cholecystitis: gallbladder volvulus.

Gallbladder volvulus is a rare condition with similar presentation to acute cholecystitis. It is caused by the gallbladder twisting upon its mesentery leading to potential ischemia and biliary obstruction. A 77-year-old female presented with symptoms of right upper quadrant pain and nausea. She was found to have an elevated leukocytosis and a palpable right upper quadrant abdominal mass on exam. Imaging revealed a severely distended gallbladder with pericholecystic fluid and wall thickening without gallstones. Intraoperatively, an extremely distended, ischemic gallbladder was noted to have twisted upon its mesentery. The structures were able to be identified and the gallbladder was able to be safely removed with a laparoscopic approach despite its large size. Gallbladder volvulus is important to consider in the differential of acute cholecystitis because delay in intervention could lead to gallbladder necrosis and possible perforation, increasing the patient's morbidity and mortality.

Adaptive cultural transmission biases in children and nonhuman primates.

Comparative and evolutionary developmental analyses seek to discover the similarities and differences between humans and non-human species that might illuminate both the evolutionary foundations of our nature that we share with other animals, and the distinctive characteristics that make human development unique. As our closest animal relatives, with whom we last shared common ancestry, non-human primates have been particularly important in this endeavour. Such studies have focused on social learning, traditions, and culture, and have discovered much about the 'how' of social learning, concerned with key underlying processes such as imitation and emulation. One of the core discoveries is that the adaptive adjustment of social learning options to different contexts is not unique to human, therefore multiple new strands of research have begun to focus on more subtle questions about when, from whom, and why such learning occurs. Here we review illustrative studies on both human infants and young children and on non-human primates to identify the similarities shared more broadly across the primate order, and the apparent specialisms that distinguish human development. Adaptive biases in social learning discussed include those modulated by task comprehension, experience, conformity to majorities, and the age, skill, proficiency and familiarity of potential alternative cultural models.

Abdominal cocoon: idiopathic sclerosing encapsulating peritonitis.

Abdominal cocoon, or idiopathic sclerosing encapsulating peritonitis, is a rare condition characterised by the presence of a dense fibrocollagenous membrane partially or totally encapsulating the small bowel leading to recurrent intestinal obstructions. We present the case of a patient who has presented for the fourth time with a small bowel obstruction. Previous laparoscopy revealed a plaque-like reactive process encapsulating much of the small bowel and the liver. After initial adhesiolysis, the patient's obstructions continued to reoccur. Further laparotomy was performed in order to excise the entirety of the cocoon membrane and free up loops of small bowel encapsulated by the process, hopefully preventing future obstructions.

Imitation by combination: preschool age children evidence summative imitation in a novel problem-solving task.

Children are exceptional, even 'super,' imitators but comparatively poor independent problem-solvers or innovators. Yet, imitation and innovation are both necessary components of cumulative cultural evolution. Here, we explored the relationship between imitation and innovation by assessing children's ability to generate a solution to a novel problem by imitating two different action sequences demonstrated by two different models, an example of imitation by combination, which we refer to as "summative imitation." Children (N = 181) from 3 to 5 years of age and across three experiments were tested in a baseline condition or in one of six demonstration conditions, varying in the number of models and opening techniques demonstrated. Across experiments, more than 75% of children evidenced summative imitation, opening both compartments of the problem box and retrieving the reward hidden in each. Generally, learning different actions from two different models was as good (and in some cases, better) than learning from 1 model, but the underlying representations appear to be the same in both demonstration conditions. These results show that summative imitation not only facilitates imitation learning but can also result in new solutions to problems, an essential feature of innovation and cumulative culture.

Comparative cultural cognition.

Cultural learning is an adaptive mechanism which can lead to changes in behavior and cognition much faster than naturally selected genetic change. Although social learning is prevalent in many species, the capacity for significant cumulative culture remains restricted to humans. This capacity has been a driving force behind the evolution of complexity in our technologies and societies, and has allowed us to become the most widespread mammal on earth. The comparative study of cultural cognition assesses where important differences lie between species. A combination of observational studies in the wild, experimental studies in captivity, and field experiments together provide the most comprehensive methods with which to tackle the question. Copyright © 2009 John Wiley & Sons, Ltd. For further resources related to this article, please visit the WIREs website.