Young children do not require perceptual-motor feedback to solve Aesop's Fable tasks

Aesop's Fable tasks-in which subjects drop objects into a water-filled tube to raise the water level and obtain out-of-reach floating rewards -have been used to test for causal understanding of water displacement in both young children and non-human animals. However, a number of alternative explanations for success on these tasks have yet to be ruled out. One hypothesis is that subjects may respond to perceptual-motor feedback: repeating those actions that bring the reward incrementally closer. Here, we devised a novel, forced-choice version of the Aesop's Fable task to assess whether subjects can solve water displacement tasks when this type of feedback is removed. Subjects had to select only one set of objects, or one type of tube, into which all objects were dropped at once, and the effect the objects had on the water level was visually concealed. In the current experiment, fifty-five 5-9 year old children were tested in six different conditions in which we either varied object properties (floating vs. sinking, hollow vs. solid, large vs. small and too large vs. small objects), the water level (high vs. low) and/or the tube size (narrow vs. wide). We found that children aged 8-9 years old were able to solve most of the water displacement tasks on their first trial, without any opportunity for feedback, suggesting that they mentally simulated the results of their actions before making a choice. Children aged 5-7 years solved two conditions on their first trial (large vs. small objects and high- vs. low-water levels), and learnt to solve most of the remaining conditions over five trials. The developmental pattern shown here is comparable to previous studies using the standard Aesop's Fable task, where eight year olds are typically successful from their first trial and 5-7 year olds learn to pass over five trials. Thus, our results indicate that children do not depend on perceptual-motor feedback to solve these water displacement tasks. The forced-choice paradigm we describe could be used comparatively to test whether or not non-human animals require visual feedback to solve water displacement tasks

How Insightful Is 'Insight'? New Caledonian Crows Do Not Attend to Object Weight during Spontaneous Stone Dropping.

It is highly difficult to pinpoint what is going through an animal's mind when it appears to solve a problem by 'insight'. Here, we searched for an information processing error during the emergence of seemingly insightful stone dropping in New Caledonian crows. We presented these birds with the platform apparatus, where a heavy object needs to be dropped down a tube and onto a platform in order to trigger the release of food. Our results show New Caledonian crows exhibit a weight inattention error: they do not attend to the weight of an object when innovating stone dropping. This suggests that these crows do not use an understanding of force when solving the platform task in a seemingly insightful manner. Our findings showcase the power of the signature-testing approach, where experiments search for information processing biases, errors and limits, in order to make strong inferences about the functioning of animal minds.Work was funded by a Rutherford Discovery Fellowship from the Royal Society of New Zealand (AHT). SAJ would like to thank the ERC for funding. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

New Caledonian crows rapidly solve a collaborative problem without cooperative cognition

There is growing comparative evidence that the cognitive bases of cooperation are not unique to humans. However, the selective pressures that lead to the evolution of these mechanisms remain unclear. Here we show that while tool-making New Caledonian crows can produce collaborative behavior, they do not understand the causality of cooperation nor show sensitivity to inequity. Instead, the collaborative behavior produced appears to have been underpinned by the transfer of prior experience. These results suggest that a number of possible selective pressures, including tool manufacture and mobbing behaviours, have not led to the evolution of cooperative cognition in this species. They show that causal cognition can evolve in a domain specific manner-understanding the properties and flexible uses of physical tools does not necessarily enable animals to grasp that a conspecific can be used as a social tool

Comparing the non-linguistic hallmarks of episodic memory systems in corvids and children

Much of the debate over whether food-caching corvids possess an episodic memory system — comparable to that of humans — has focussed on these birds’ memories for what was cached, where and when. Here, we highlight that corvids also exhibit a number of other behaviours that could potentially be considered non-linguistic hallmarks of an episodic-memory system, including the ability to produce rich, flexible representations of various past events, and to prepare for specific events in the future in a number of different ways. Direct comparisons of these experiments are beginning to emerge with young children. These studies allow us to determine whether performance on episodic-like memory tasks follows a similar developmental trajectory to performance on other measures of episodic memory. Here, we discuss some of the similarities and differences between the minds of corvids and children that have emerged from this research to date.SAJ and NSC received funding from the European Research Council under the European Union's Seventh Framework Programme (FP7/2007–2013)/ERC Grant Agreement No. 3399933, awarded to NSC

The interplay between psychological predispositions and skill learning in the evolution of tool use

Tool use behaviours tend to be split into cases that appear to entail complex cognitive abilities and that are highly reliant on learning to be acquired (e.g. flexible tool use), and into others that seem to be more genetically canalized (e.g. stereotyped tool use). However recent evidences suggest that the differences between these forms of tool use are more nuanced than previously assumed, as in both cases tool use can entail some degree of both inborn predisposition and learning. Here, we particularly discuss the role played by intrinsic (e.g. not socially induced) motivation towards the manipulation of objects, in the emergence of flexible tool use. We highlight the importance of focussing on these psychological predispositions to understand the rarity of tool use among wild animals, as well as the higher proficiency in using tools that some species non-tool users express in captivity