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A fundamental component of human cognition is the ability to intuitively reason about behaviours of objects and systems in the physical world without resorting to explicit scientific knowledge. This skill was traditionally considered a symbolic process. However, in the last decades, there has been a shift towards ideas of embodiment, suggesting that accessing physical knowledge and predicting physical outcomes is grounded in bodily interactions with the environment. Infants and children, who learn mainly through their embodied experiences, serve as a model to probe the link between reasoning and physical concepts. Here, we tested school-aged children (5- to 15-year-olds) in online reasoning games that involve different physical action concepts such as supporting, launching and clearing. We assessed changes in children's performance and strategies over development and their relationships with the different action concepts. Children reasoned more accurately in problems that involved supporting actions compared to launching or clearing actions. Moreover, when children failed, they were more strategic in subsequent attempts when problems involved support rather than launching or clearing. Children improved with age, but improvements differed across action concepts. Our findings suggest that accessing physical knowledge and predicting physical events are affected by action concepts, and those effects change over development. This article is part of the theme issue 'Minds in movement: embodied cognition in the age of artificial intelligence'. [ABSTRACT FROM AUTHOR]

Previous research on human infants has shown that violations of basic physical regularities can stimulate exploration, which may represent a type of hypothesis testing aimed at acquiring knowledge about new causal relationships. In this study, we examined whether a similar connection between expectancy violation and exploration exists in nonhuman animals. Specifically, we investigated how dogs react to expectancy violations in the context of occlusion events. Throughout three experiments, dogs exhibited longer looking times at expectancy-inconsistent events than at consistent ones. This finding was further supported by pupil size analyses in the first two eye-tracking experiments. Our results suggest that dogs expect objects to reappear when they are not obstructed by a screen and consider the size of the occluding screen in relation to the occluded object. In Experiment 3, expectancy violations increased the dogs' exploration of the target object, similar to the findings with human infants. We conclude that expectancy violations can provide learning opportunities for nonhuman animals as well. [ABSTRACT FROM AUTHOR]

The string-pulling paradigm is an approach commonly used in the study of animal cognition to investigate problem-solving abilities. This test involves an out-of-reach reward that can only be acquired through pulling a string. Australian magpies (Gymnorhina tibicen tyrannica) can solve cognitive tasks requiring associative and reversal learning, spatial memory, and inhibitory control. Nonetheless, whether magpies can pass a test of means-end understanding—the string-pull test—is unclear. We tested wild magpies on a string-pulling task with five configurations, including a long loose string that required several pulls to obtain food, a short string that only required a single pull to complete, and two short strings—one intact and connected to the food reward; the other broken and unable to yield food when pulled. Of the 11 magpies tested, none solved the long string task at first presentation. Two naïve birds and three, subsequently trained, birds succeeded at the short string. Once proficient at the short string, four of these five birds then solved the long string task; in addition, three learned to choose a functional, intact string over a non-functional, broken string. Overall, these observations provide evidence that Australian magpies have the ability to solve string-pulling tasks but it remains unclear whether they do so by trial-and-error or if they possess means-end understanding. Significance statement: We found, for the first time, that wild, free-ranging Australian magpies can learn to solve different versions of a string-pulling task; a version with a short string, a long string, and two strings next to each other where one of them was broken and non-functional (broken string task). Some magpies spontaneously solved the task with the short string, where other magpies required training, and magpies only managed to solve the task with the long string after they had succeeded on the short string task. Furthermore, some of the magpies solved the broken string task but required a high number of trials to do so. Overall, our findings show that Australian magpies have the ability to solve string-pulling tasks but it remains unclear whether they do so by trial-and-error or if they understand causal relations between objects. [ABSTRACT FROM AUTHOR]

Corvids are known for their cognitive flexibility, and many have innovated various forms of tool use. Here, we review tool use and tooling in common ravens (Corvus corax) and describe additional observations. In total, they have used tools in 10 submodes and 11 modes. Of these modes, four were observed in captivity only, four in the wild only and three in both contexts. Five of these modes constitute tooling. When they manufactured tools, it was through detachment or subtraction. The purpose of most tool use was apparent, except when they used containers to transport small amounts of food that could be held in their bill and antelingual pouch (estimated to hold at least 16.2 ml). The small number of tool‐using individuals per mode and the lack of detailed descriptions limit further interpretation and generalizability. Nonetheless, ravens are likely customary tool users in three modes and show the capacity for diverse tool use, which should be examined in dedicated future experiments. [ABSTRACT FROM AUTHOR]

Psittacines, along with corvids, are commonly referred to as 'feathered apes' due to their advanced cognitive abilities. Until rather recently, the research effort on parrot cognition was lagging behind that on corvids, however current developments show that the number of parrot studies is steadily increasing. In 2018, M. L. Lambert et al. provided a comprehensive review on the status of the most important work done so far in parrot and corvid cognition. Nevertheless, only a little more than 4 years after this publication, more than 50 new parrot studies have been published, some of them chartering completely new territory. On the 25th anniversary of Animal Cognition we think this warrants a detailed review of parrot cognition research over the last 4 years. We aim to capture recent developments and current trends in this rapidly expanding and diversifying field. [ABSTRACT FROM AUTHOR]

Humans and nonhuman great apes share a sense for intuitive statistics, making intuitive probability judgments based on proportional information. This ability is of tremendous importance, in particular for predicting the outcome of events using prior information and for inferring general regularities from limited numbers of observations. Already in infancy, humans functionally integrate intuitive statistics with other cognitive domains, rendering this type of reasoning a powerful tool to make rational decisions in a variety of contexts. Recent research suggests that chimpanzees are capable of one type of such cross-domain integration: The integration of statistical and social information. Here, we investigated whether apes can also integrate physical information into their statistical inferences. We tested 14 sanctuary-living chimpanzees in a new task setup consisting of two “gumball machine”-apparatuses that were filled with different combinations of preferred and non-preferred food items. In four test conditions, subjects decided which of two apparatuses they wanted to operate to receive a random sample, while we varied both the proportional composition of the food items as well as their spatial configuration above and below a barrier. To receive the more favorable sample, apes needed to integrate proportional and spatial information. Chimpanzees succeeded in conditions in which we provided them either with proportional information or spatial information, but they failed to correctly integrate both types of information when they were in conflict. Whether these limitations in chimpanzees' performance reflect true limits of cognitive competence or merely performance limitations due to accessory task demands is still an open question.

Although reports of animal tool‐use are phylogenetically widespread, it remains rare in the wild. From the perspective of human evolution, this rarity was first explained by the cognitive demands associated with tool use. Recently, an alternative assumption, "the tools are not often useful" hypothesis, proposes that tool use is rare, because it is seldom more useful than the species' anatomical adaptations. At the same time, several species that do not use tools in the wild have shown the capacity for tool use in experimental problem‐solving settings, which suggests a certain level of cognitive flexibility. Investigating whether habitually non‐tool‐using species are able to use tools flexibly is crucial to evaluate the predictions of existing theories on the evolution of cognition. In this study, we tested whether great white pelicans (Pelecanus onocrotalus), morphologically specialized fishers, for whose natural foraging tools are unlikely to be of use, were able to use tools in two problem‐solving situations. In two tasks, the subjects were required to drop tools into an apparatus to gain access to a food reward. In Tool‐use task 1, we tested the capacity of pelicans to show spontaneous tool‐use behaviour. In Tool‐use task 2, we assessed the birds' tool‐using performance, before and after providing them with different kinds of information about the task's solution, that is experience with the functional features of the apparatus ("platform‐pushing group") and trial‐and‐error learning of tool‐dropping behaviour ("stone‐nudging group"). All subjects failed in using tools in Tool‐use task 1 and only one individual in the stone‐nudging group learnt to use a tool in the training phase of Tool‐use task 2. Despite previous experience with the functional properties of the task, birds from the platform‐pushing group did not exhibit tool‐use behaviour or increased motivation towards the apparatus and the tools during the test phase. Although pelicans were not inhibited by morphological constraints to carry out the required tool behaviours, whether they lack the cognitive prerequisites for flexible tool‐use remains to be further tested. [ABSTRACT FROM AUTHOR]

Eurasian jays (Garrulus glandarius) do not habitually use tools, yet they can be trained to solve object-dropping tasks, i.e., to insert a tool into an apparatus to release a food reward. Previous research suggests that these jays can learn a preference toward functional tools – objects allowing them to obtain a food reward placed inside an apparatus – according to their density (Cheke et al., 2011). However, it is not yet known whether they can also select functional tools (tool selectivity) according to other physical properties such as size and shape and use different kinds of tools to solve a similar task. Here we conducted three object-dropping experiments aimed at exploring these abilities in Eurasian jays. In Experiment 1, jays tended to select large stones as tools irrespective of the diameter of the apparatus. However, jays progressively developed a preference for the small tool, which was functional with both the wide and the narrow apparatuses. In Experiment 2, only vertically oriented long stones could fit into the narrow apparatus, whereas both long and round stones were functional with the wide apparatus. Jays showed a preference for the long stone and, with the narrow apparatus, tended to achieve the correct manipulation after one or more unsuccessful attempts. In Experiment 3, jays were able to use sticks and adopt a novel technique on the same object-dropping apparatus, thus providing the first evidence that Eurasian jays can use sticks as tools. Taken together, these results do not support the notion that tool selectivity abilities can be found in Eurasian jays but nonetheless show that these corvids can use different kinds of tools to solve similar tasks.

Scientific disciplines face concerns about replicability and statistical inference, and these concerns are also relevant in animal cognition research. This paper presents a first attempt to assess how researchers make and publish claims about animal physical cognition, and the statistical inferences they use to support them. We surveyed 116 published experiments from 63 papers on physical cognition, covering 43 different species. The most common tasks in our sample were trap-tube tasks (14 papers), other tool use tasks (13 papers), means-end understanding and string-pulling tasks (11 papers), object choice and object permanence tasks (9 papers) and access tasks (5 papers). This sample is not representative of the full scope of physical cognition research; however, it does provide data on the types of statistical design and publication decisions researchers have adopted. Across the 116 experiments, the median sample size was 7. Depending on the definitions we used, we estimated that between 44% and 59% of our sample of papers made positive claims about animals’ physical cognitive abilities, between 24% and 46% made inconclusive claims, and between 10% and 17% made negative claims. Several failures of animals to pass physical cognition tasks were reported. Although our measures had low inter-observer reliability, these findings show that negative results can and have been published in the field. However, publication bias is still present, and consistent with this, we observed a drop in the frequency of p-values above .05. This suggests that some non-significant results have not been published. More promisingly, we found that researchers are likely making many correct statistical inferences at the individual-level. The strength of evidence of statistical effects at the group-level was weaker, and its p-value distribution was consistent with some effect sizes being overestimated. Studies such as ours can form part of a wider investigation into statistical reliability in comparative cognition. However, future work should focus on developing the validity and reliability of the measurements they use, and we offer some starting points.

When chimpanzees (and other animals) use tools to pound, crack open, retrieve, soak up, pry apart, probe into, and/or dig up other objects (just to name a few of the operations of which they are capable), are these actions modulated by higher-order, structural, role-based representations of , , , and so forth? We report a study that was designed to shed light on what chimpanzees understand about and between objects. We presented expert tool-using chimpanzees with very familiar objects (ropes) in a very familiar testing context (hooking and retrieving an object containing food). We investigated whether they could transfer the known operation (hooking and pulling) to two distinct setups involving ropes (a looped rope that could effectuate the transfer of force, and a draped length of rope that could not¾unless both ends were grasped at the same time). We show that first-order, perceptually-based relational reasoning is both necessary and sufficient to explain not only the impressive pattern of results we did obtain, but any possible pattern of results we could have obtained. If correct, any claim that higher-order reasoning is necessary to explain the results of such a test would, by definition, be false. More importantly, we show that this is not an idiosyncratic limitation of this experiment. Instead, we show that all experimental protocols claiming to assay higher-order reasoning in animals rest upon an extremely suspect, and ultimately unprincipled, titration. Specifically, researchers implicitly assume that the tasks are perceptually similar enough to what their subjects have previously encountered to allow them make sense of the problem, but perceptually different enough that the subjects must (somehow) rely upon higher-order reasoning to navigate their way through it. We show why such assumptions are false.

Humans form abstract representations about the physical properties of objects, with very young infants having ‘core knowledge’ about solidity and continuity. Whether nonhuman primates also form abstract representation of physical properties is debated. Despite studies showing that some nonhuman primates can discriminate between functional and non-functional tools, whether they achieve this by recognizing an object’s physical properties or via associative learning of perceptual cues remains contested. One method for exploring an individual’s physical cognition is the trap-tube (where subjects push a reward out of a pipe whilst avoiding a trap). The trap-tube investigates whether participants understand that rewards cannot pass through solid objects (solidity) and that unsupported objects will fall (gravity). Initial research reported that chimpanzees and capuchin monkeys solved the test using associative rules; however, modifying the task by removing the tool revealed an understanding of solidity in chimpanzees. In this series of studies, we tested 12 squirrel monkeys and 14 capuchin monkeys on a modified trap-box, where the monkeys could move the reward using their fingers rather than a tool. No individual of either species passed the task at above chance levels. In Experiment 2, the same trap blocked one of two cups: both species learned to avoid it. In Experiment 3, only capuchins generalized this solution to novel materials, performing better when cues had a functional versus a non-functional relationship to the outcome. Squirrel monkeys appeared to learn via association, while results from capuchins indicated a sensitivity to the concept of solidity.

Humans' flexible innovation relies on our capacity to accurately predict objects' behaviour. These predictions may originate from a "physics-engine" in the brain which simulates our environment. To explore the evolutionary origins of intuitive physics, we investigate whether capuchin monkeys' object exploration supports learning. Two capuchin groups experienced exploration sessions involving multiple copies of two objects, one object was easily opened (functional), the other was not (non-functional). We used two within-subject conditions (enrichment-then-test, and test-only) with two object sets per group. Monkeys then underwent individual test sessions where the objects contained rewards, and they choose one to attempt to open. The monkeys spontaneously explored, performing actions which yielded functional information. At test, both groups chose functional objects above chance. While high performance of the test-only group precluded us from establishing learning during exploration, this study reveals the promise of harnessing primates' natural exploratory tendencies to understand how they see the world. [ABSTRACT FROM AUTHOR]

Being able to make and use tools was once considered to be an evolutionary hallmark of our species, but has since been documented in other animals. However, for reasons that remain unclear, not all species naturally use tools. Racoons (Procyon lotor) are generalist carnivores that possess many of the physical, cognitive, and behavioural characteristics linked to tool use in other species (e.g. manual dexterity, tactile exploration, relatively large brains, extractive foraging, and sociality). Although raccoons have not been observed using tools outside of experimental captive conditions, wild data involving objective psychometric tests are needed. The current study administered a tool-related task to a wild population of raccoons from 20 locations within the Croatan National Forest, USA. The task required participants to use a stick to extract food from a pipe. To facilitate interpretations of their performances on the task, data were obtained on natural tool availability at the field site and participants' mode of exploring the novel task. None of the participants solved the task despite natural sticks (suitable for solving the task) being widely available across testing locations. Participants were equally likely to smell versus handle novel sticks, which were provided at testing platforms. Limited tactile exploration, but not tool availability, could be at least one factor that reduces these raccoons' opportunities to interact with and learn about novel tools like sticks. [ABSTRACT FROM AUTHOR]

Goffin's cockatoos, a parrot species endemic to the Tanimbar Islands in Indonesia, demonstrate remarkable cognitive skills across various technical tasks. These neophilic extractive foragers explore objects with their beak and feet, and are skilled in several modes of tool use. In this study, we confronted the animals for the first time with a vertical string-pulling setup, including a set of classic and novel controls. Nine of the 12 subjects, two of which were subadults, immediately interacted with the single-string task, with seven individuals successfully obtaining the reward on their very first attempt. Four different double string discrimination tests with varying spatial relations were used to assess the Goffin's cockatoos' apprehension of basic physical task properties. We found significant differences in performance between the respective experimental conditions, as well as the development of side biases. The results suggest that while the birds seem to consider simple cause–effect relationships, there is no evidence for a mental representation of the causal mechanisms underlying the string-pulling tasks, as subjects failed the crossed strings condition out of immediate sight. Finally, we provide suggestions on improving the methodology, and discuss our findings in regard to the Goffin's cockatoo's ecology. [ABSTRACT FROM AUTHOR]

Behavioural innovations with tool-like objects in non-habitually tool-using species are thought to require complex physical understanding, but the underlying cognitive processes remain poorly understood. A few parrot species are capable of innovating tool-use and borderline tool-use behaviours. We tested this capacity in two species of macaw (Ara ambiguus, n = 9; Ara glaucogularis, n = 8) to investigate if they could solve a problem-solving task through manufacture of a multi-stone construction. Specifically, after having functional experience with a pre-inserted stick tool to push a reward out of a horizontal tube, the subjects were required to insert five stones consecutively from one side to perform the same function as the stick tool with the resulting multi-component construction. One Ara glaucogularis solved the task and innovated the stone construction after the experience with the stick tool. Two more subjects (one of each species) did so after having further functional experience of a single stone pushing a reward out of a shortened tube. These subjects were able to consistently solve the task, but often made errors, for example counter-productive stone insertions from the opposing end, even in some of the successful trials. Conversely, multiple trials without errors also suggested a strong goal direction. Their performance in the follow-up tasks was inconclusive since they sometimes inserted stones into un-baited or blocked 'dummy tubes', but this could have been an attention-deficit behaviour as subjects had not encountered these 'dummy tubes' before. Overall, the successful subjects' performance was so erratic that it proved difficult to conclude whether they had functional understanding of their multi-stone constructions. [ABSTRACT FROM AUTHOR]

Through the mechanisms of observation, imitation and teaching, young children readily pick up the tool using behaviours of their culture. However, little is known about the baseline abilities of children's tool use: what they might be capable of inventing on their own in the absence of socially provided information. It has been shown that children can spontaneously invent 11 of 12 candidate tool using behaviours observed within the foraging behaviours of wild non-human apes (Reindl et al. 2016 Proc. R. Soc. B 283, 20152402. (doi:10.1098/rspb.2015.2402)). However, no investigations to date have examined how tool use invention in children might vary across cultural contexts. The current study investigated the levels of spontaneous tool use invention in 2- to 5-year-old children from San Bushmen communities in South Africa and children in a large city in Australia on the same 12 candidate problem-solving tasks. Children in both cultural contexts correctly invented all 12 candidate tool using behaviours, suggesting that these behaviours are within the general cognitive and physical capacities of human children and can be produced in the absence of direct social learning mechanisms such as teaching or observation. Children in both cultures were more likely to invent those tool behaviours more frequently observed in great ape populations than those less frequently observed, suggesting there is similarity in the level of difficulty of invention across these behaviours for all great ape species. However, children in the Australian sample invented tool behaviours and succeeded on the tasks more often than did the Bushmen children, highlighting that aspects of a child's social or cultural environment may influence the rates of their tool use invention on such task sets, even when direct social information is absent.

Animals' cognitive abilities can be tested by allowing them to choose between alternatives, with only one alternative offering the correct solution to a novel problem. Hermit crabs are evolutionarily specialized to navigate while carrying a shell, with alternative shells representing different forms of 'extended architecture', which effectively change the extent of physical space an individual occupies in the world. It is unknown whether individuals can choose such architecture to solve novel navigational problems. Here, we designed an experiment in which social hermit crabs (Coenobita compressus) had to choose between two alternative shells to solve a novel problem: escaping solitary confinement. Using X-ray microtomography and 3D-printing, we copied preferred shell types and then made artificial alterations to their inner or outer shell architecture, designing only some shells to have the correct architectural fit for escaping the opening of an isolated crab's enclosure. In our 'escape artist' experimental design, crabs had to choose an otherwise less preferred shell, since only this shell had the right external architecture to allow the crab to free itself from isolation. Across multiple experiments, crabs were willing to forgo preferred shells and choose less preferred shells that enabled them to escape, suggesting these animals can solve novel navigational problems with extended architecture. Yet, it remains unclear if individuals solved this problem through trial-and-error or were aware of the deeper connection between escape and exterior shell architecture. Our experiments offer a foundation for further explorations of physical, social, and spatial cognition within the context of extended architecture. [ABSTRACT FROM AUTHOR]

Capuchins (Sapajus apella) and squirrel monkeys (Saimiri sciureus) participated in 3 experiments in which they were presented with 2 objects, one appropriately oriented and the other inappropriately oriented to retrieve a food reward by pulling, replicating prior experiments with nonhuman primates described as evaluating "tool choice." Choice patterns were analyzed to assess whether monkeys learned that tools needed to be oriented with part of the tool on the far side of the reward to pull in the food. Both species learned to choose appropriately oriented tools after a similar number of sessions with a cane-shaped tool in the first task. Both species also transferred to a new tool shape in the second task, but squirrel monkeys' performance on particular trials suggested they did not use the functional relationship between the tool and the food to guide their choices. Tool shapes and configurations in the final task were designed to control for the potential use of extraneous spatial cues. Neither capuchins nor squirrel monkeys chose appropriately oriented tools above chance in control trials. Results suggest both species relied on other spatial cues to perform in previous tasks rather than learning to attend to the functional spatial relationship between a tool and a reward. Species differences emerged in the second task only, as capuchins mastered performance with the new tool shape faster than squirrel monkeys and seemed to use a more complex set of rules to guide their choices. [ABSTRACT FROM AUTHOR]

Systematic, broad phylogenetic comparisons of diverse cognitive abilities are essential to understand cognitive evolution. Few studies have examined multiple skills comparatively, using identical tasks across species. Previous research centered on primates, but recent evidence suggests that complex cognition may have evolved in distantly related taxa. We administered the tasks of the primate cognition test battery (PCTB) to 4 parrot species for a first direct comparison with primates. The parrots did not perform significantly worse than the previously tested primates in all but one of the test scales, but remained at chance levels throughout. Chimpanzees outperformed them in the physical but not the social domain. No differences between the domains nor across the parrot species were detected. It remains questionable whether the chance level performance reflects the parrots' cognitive capacity or results from task constraints, which would limit the suitability of PCTB for phylogenetic comparisons. Possible implications for the field are discussed. [ABSTRACT FROM AUTHOR]

The last several decades of research on avian cognition have revealed surprising parallels between the abilities of birds — most notably corvids — and great apes. Parrots, albeit far less studied, are cited alongside corvids as "feathered apes", but are these two taxa really that similar cognitively? In this review we aim to take a step back and present the broader picture, focusing on areas where there is now data from both parrots and corvids to facilitate first comparisons on a somewhat wider scale. By charting these birds' performance in cognitive tasks, in many of which corvids perform on par with primates, we hope to highlight understudied areas and promising directions for future research. In reviewing the literature, the general pattern that emerges shows that different corvid and parrot species indeed perform similarly in a range of cognitive tasks to the extent that one may call them "feathered apes". [ABSTRACT FROM AUTHOR]

This study investigates problem solving in one northern ground hornbill (Bucorvus abyssinicus) and two southern ground-hornbills (Bucorvus leadbeateri) in a horizontal string-pulling task. In five conditions, two strings were stretched out on the ground and subjects had to pull the end of the string which was properly connected to an out-of-reach food reward. Two subjects succeeded above chance in choosing a rewarded string over an unrewarded one (parallel and converged conditions), and continued pulling longer strings when the reward did not immediately move closer (coiled condition). One bird additionally understood which string was physically connected to the reward (contact condition). Although this study is preliminary, it highlights the necessity to extend research on physical cognition to other large-brained avian orders in order to better understand the underlying ecological and social selection pressures involved. [ABSTRACT FROM AUTHOR]

Despite being closely related, dogs perform worse than wolves in independent problem-solving tasks. These differences in problem-solving performance have been attributed to dogs’ greater reliance on humans, who are usually present when problem-solving tasks are presented. However, more fundamental motivational factors or behavioural traits such as persistence, motor diversity and neophobia may also be responsible for differences in task performance. Hence, to better understand what drives the differences between dogs’ and wolves’ problem-solving performance, it is essential to test them in the absence of humans. Here, we tested equally raised and kept dogs and wolves with two unsolvable tasks, a commonly used paradigm to study problem-solving behaviour in these species. Differently from previous studies, we ensured no humans were present in the testing situation. We also ensured that the task was unsolvable from the start, which eliminated the possibility that specific manipulative behaviours were reinforced. This allowed us to measure both persistence and motor diversity more accurately. In line with previous studies, we found wolves to be more persistent than dogs. We also found motor diversity to be linked to persistence and persistence to be linked to contact latency. Finally, subjects were consistent in their performance between the two tasks. These results suggest that fundamental differences in motivation to interact with objects drive the differences in the performance of dogs and wolves in problem-solving tasks. Since correlates of problem-solving success, that is persistence, neophobia, and motor diversity are influenced by a species’ ecology, our results support the socioecological hypothesis, which postulates that the different ecological niches of the two species (dogs have evolved to primarily be scavengers and thrive on and around human refuse, while wolves have evolved to primarily be group hunters and have a low hunting success rate) have, at least partly, shaped their behaviours.

Despite being closely related, dogs perform worse than wolves in independent problem-solving tasks. These differences in problem-solving performance have been attributed to dogs' greater reliance on humans, who are usually present when problem-solving tasks are presented. However, more fundamental motivational factors or behavioural traits such as persistence, motor diversity and neophobia may also be responsible for differences in task performance. Hence, to better understand what drives the differences between dogs' and wolves' problem-solving performance, it is essential to test them in the absence of humans. Here, we tested equally raised and kept dogs and wolves with two unsolvable tasks, a commonly used paradigm to study problem-solving behaviour in these species. Differently from previous studies, we ensured no humans were present in the testing situation. We also ensured that the task was unsolvable from the start, which eliminated the possibility that specific manipulative behaviours were reinforced. This allowed us to measure both persistence and motor diversity more accurately. In line with previous studies, we found wolves to be more persistent than dogs. We also found motor diversity to be linked to persistence and persistence to be linked to contact latency. Finally, subjects were consistent in their performance between the two tasks. These results suggest that fundamental differences in motivation to interact with objects drive the differences in the performance of dogs and wolves in problem-solving tasks. Since correlates of problem-solving success, that is persistence, neophobia, and motor diversity are influenced by a species' ecology, our results support the socioecological hypothesis, which postulates that the different ecological niches of the two species (dogs have evolved to primarily be scavengers and thrive on and around human refuse, while wolves have evolved to primarily be group hunters and have a low hunting success rate) have, at least partly, shaped their behaviours. [ABSTRACT FROM AUTHOR]

Tool use relies on numerous cognitive functions, including sustained attention and understanding of causality. In this study, we investigated the effects of tool-use training on cognitive performance in primates. Specifically, we applied the Primate Cognition Test Battery to three long-tailed macaques (Macaca fascicularis) at different stages of a training procedure that consisted of using a rake to retrieve out-of-reach food items. In addition, we evaluated a control group (n = 3) performing a grasping task, in order to account for possible effects related to a simple motor act. Our results showed that tool-use training enhances mean performance in the physical cognition domain, i.e. the understanding of spatial relations, numerosity and causality. In particular, causal cognition (evaluating noise- and shape-related causality and understanding of tool properties) showed significant improvement after training, whereas spatial cognition (evaluating spatial memory, object permanence, rotation and transposition) showed a trend to improvement. Despite these findings, none of our trained monkeys succeeded in the tool-use task of the Primate Cognition Test Battery, which involved an unfamiliar tool. Some training-related effects did not persist after a 35-day resting period, suggesting that continuous practice may be necessary, or that a longer training period before resting may be needed to better maintain cognitive performance. In contrast with the training group, the control group did not display any change in cognitive performance. This finding paves the way to further investigation into the link between tool-use behaviour and the evolution of primate cognition. [ABSTRACT FROM AUTHOR]

Play is widespread among vertebrates. Some animal groups stand out in their play behaviors in levels of complexity, innovativeness, sociality, and volume. Despite the vast phylogenetic distance between corvids, parrots, great apes, and dolphins, all are usually identified as among the most playful. These groups also have several complex cognitive skills in common. There is growing agreement that play has evolved multiple times under different selective pressures in different lineages. As these groups appear similar in their complex play but are separated by considerable evolutionary distance, the similarity is unlikely to result from homology. Far more probable is that the similarity has arisen from convergent or parallel evolution. It is important to conduct comparative ontogenetic play studies on these groups to learn more about what basic processes underlie complex play and whether such play is, indeed, related to complex cognition. Toward that end, we explored the play behavior of raven nestlings over the last ten days before they fledged. We found high levels of play both in terms of instances initiated and duration. The play behaviors were at level with – or above – maintenance behaviors and flight training. Most of the play was object play, but social object play and apparent play contagion was also recorded. The importance of play in developing young ravens is clear. The reasons might be less clear, however play could underlie both object-related and social development.

Recent studies have shown that several species within the Carnivore order show impressive cognitive skills. However, bears, especially sloth bears, have received little attention with regard to their cognitive abilities. Here we presented seven sloth bears with three tasks to test their object permanence, short-term memory and ability to use acoustic cues to infer food location. In the object permanence test, subjects saw an object disappear in one of the three holes of a tree trunk. Bears retrieved the food in the correct hole significantly above chance, suggesting that they have some basic understanding that objects continue to exist even when they are not visible. To study sloth bears' short-term memory, we used different time delays (30 s, 60 s, 2 min) between the object's disappearance and the subject's retrieval. Bears performed at chance levels in all conditions. In the acoustic cues test, the experimenter shook one of two identical opaque containers, only one of which had been baited: when the baited container was shaken, this made a noise and thus revealed the presence of food inside; when the unbaited container was shaken, there was no noise, revealing by exclusion the presence of food in the other container. In both cases, bears selected the baited container significantly above chance. As sloth bears are a mainly insectivorous solitary species, good performance in the object permanence and acoustic cue tests suggests that their cognitive skills may be the result of foraging challenges rather than social ones. Failure in the short-term memory test, instead, may suggest that memory for short-term punctual events has little evolutionary significance for bears, although further studies are needed to draw definitive conclusions. [ABSTRACT FROM AUTHOR]

Domestic dogs' ( Canis lupus familiaris) socio-cognitive faculties have made them highly sensitive to human social cues. While dogs often excel at understanding human communicative gestures, they perform comparatively poorly in problem-solving and physical reasoning tasks. This difference in their behaviour could be due to the lifestyle and intense socialization, where problem solving and physical cognition are less important than social cognition. Free-ranging dogs live in human-dominated environments, not under human supervision and are less socialized. Being scavengers, they often encounter challenges where problem solving is required in order to get access to food. We tested Indian street dogs in familiar and unfamiliar independent solvable tasks and quantified their persistence and dependence on a novel human experimenter, in addition to their success in solving a task. Our results indicate that free-ranging dogs succeeded and persisted more in the familiar task as compared to the unfamiliar one. They showed negligible amount of human dependence in the familiar task, but showed prolonged gazing and considerable begging behaviour to the human experimenter in the context of the unfamiliar task. Cognitive abilities of free-ranging dogs thus play a pivotal role in determining task-associated behaviours based on familiarity. In addition to that, these dogs inherently tend to socialize with and depend on humans, even if they are strangers. Our results also illustrate free-ranging dogs' low competence at physical cognitive tasks. [ABSTRACT FROM AUTHOR]

Through using the method of literature review, logical dialectics, induction and deduction, the author makes an analysis on the heritage of Wushu educational experience, the result shows that Wushu inheritance is a hierarchical educational practice of "from technique to philosophy" process oriented by physical cognition where the body cognition to physical health is the cognition of structure and function. The Wushu inheritance includes three stages: similar imitation, skillful technique, and identical philosophy. Each stage has its main body education, and it also has the content of education through each stage. Wushu education heritage is not only the response to cultural consciousness, but also the educational transfer from memorizing motions to the cognition of physical structure and functions in school Wushu education, realizing the true essence of Wushu education heritage. [ABSTRACT FROM AUTHOR]

String-pulling is a widely used paradigm in animal cognition research to assess what animals understand about the functionality of strings as a means to obtain an out-of-reach reward. This study aimed to systematically investigate what rules Western scrub-jays ( Aphelocoma californica) use to solve different patterned string tasks, i.e. tasks in which subjects have to choose between two or more strings of which only one is connected to the reward, or where one is more efficient. Arranging strings in a parallel configuration showed that the jays were generally capable of solving multiple-string tasks and acted in a goal-directed manner. The slanted and crossed configurations revealed a reliance on a 'proximity rule', that is, a tendency to choose the string-end closest to the reward. When confronted with strings of different lengths attached to rewards at different distances the birds chose according to the reward distance, preferring the reward closest to them, and were sensitive to the movement of the reward, but did not consistently prefer the shorter and therefore more efficient string. Generally, the scrub-jays were successful in tasks where the reward was closest to the string-ends they needed to pull or when string length and reward distance correlated, but the birds had problems when the wrong string-end was closest to the reward or when the food items were in close proximity to each other. These results show that scrub-jays had a partial understanding of the physical principles underlying string-pulling but relied on simpler strategies such as the proximity rule to solve the tasks. [ABSTRACT FROM AUTHOR]

Physical cognition has generally been assessed in tool-using species that possess a relatively large brain size, such as corvids and apes. Parrots, like corvids and apes, also have large relative brain sizes, yet although parrots rarely use tools in the wild, growing evidence suggests comparable performances on physical cognition tasks. It is, however, unclear whether success on such tasks is facilitated by previous experience and training procedures. We therefore investigated physical comprehension of object relationships in two non-tool-using species of captive neotropical parrots on a new means-end paradigm, the Trap-Gaps task, using unfamiliar materials and modified training procedures that precluded procedural cues. Red-shouldered macaws ( Diopsittaca nobilis) and black-headed caiques ( Pionites melanocephala) were presented with an initial task that required them to discriminate between pulling food trays through gaps while attending to the respective width of the gaps and size of the trays. Subjects were then presented with a novel, but functionally equivalent, transfer task. Six of eight birds solved the initial task through trial-and-error learning. Four of these six birds solved the transfer task, with one caique demonstrating spontaneous comprehension. These findings suggest that non-tool-using parrots may possess capacities for sophisticated physical cognition by generalising previously learned rules across novel problems. [ABSTRACT FROM AUTHOR]

In cognitive tests, animals are often given a choice between two options and obtain a reward if they choose correctly. We investigated whether task format affects subjects' performance in a physical cognition test. In experiment 1, a two-choice memory test, 15 marmosets, Callithrix jacchus , had to remember the location of a food reward over time delays of increasing duration. We predicted that their performance would decline with increasing delay, but this was not found. One possible explanation was that the subjects were not sufficiently motivated to choose correctly when presented with only two options because in each trial they had a 50% chance of being rewarded. In experiment 2, we explored this possibility by testing eight naïve marmosets and seven squirrel monkeys, Saimiri sciureus , with both the traditional two-choice and a new nine-choice version of the memory test that increased the cost of a wrong choice. We found that task format affected the monkeys' performance. When choosing between nine options, both species performed better and their performance declined as delays became longer. Our results suggest that the two-choice format compromises the assessment of physical cognition, at least in memory tests with these New World monkeys, whereas providing more options, which decreases the probability of obtaining a reward when making a random guess, improves both performance and measurement validity of memory. Our findings suggest that two-choice tasks should be used with caution in comparisons within and across species because they are prone to motivational biases. [ABSTRACT FROM AUTHOR]

It is becoming apparent that birds learn from their own experiences of nest building. What is not clear is whether birds can learn from watching conspe-cifics build. As social learning allows an animal to gain information without engaging in costly trial-and-error learning, first-time builders should exploit the successful habits of experienced builders. We presented first-time nest-building male zebra finches with either a familiar or an unfamiliar conspecific male building with material of a colour the observer did not like. When given the opportunity to build, males that had watched a familiar male build switched their material preference to that used by the familiar male. Males that observed unfamiliar birds did not. Thus, first-time nest builders use social information and copy the nest material choices when demonstrators are familiar but not when they are strangers. The relationships between individuals therefore influence how nest-building expertise is socially transmitted in zebra finches. [ABSTRACT FROM AUTHOR]

The variety and complexity of human-made tools are unique in the animal kingdom. Research investigating why human tool use is special has focused on the role of social learning: while non-human great apes acquire tool-use behaviours mostly by individual (re-)inventions, modern humans use imitation and teaching to accumulate innovations over time. However, little is known about tool-use behaviours that humans can invent individually, i.e. without cultural knowledge. We presented 2- to 3.5-year-old children with 12 problem-solving tasks based on tool-use behaviours shown by great apes. Spontaneous tool use was observed in 11 tasks. Additionally, tasks which occurred more frequently in wild great apes were also solved more frequently by human children. Our results demonstrate great similarity in the spontaneous tool-use abilities of human children and great apes, indicating that the physical cognition underlying tool use shows large overlaps across the great ape species. This suggests that humans are neither born with special physical cognition skills, nor that these skills have degraded due to our species' long reliance of social learning in the tool-use domain. [ABSTRACT FROM AUTHOR]