Crows make optimal choices based on relative probabilities.

A recent study by Johnston, Brecht, and Nieder (2023, Current Biology, 33, 3238-3243) finds that carrion crows associate varying rates of reinforcement with novel arbitrary stimuli and make optimal decisions when they must later choose between stimulus pairs. These results demonstrate that crows are capable of not only storing information about reward probabilities in their memory but also making optimal choices based on this information even a month later.

Creativity and flexibility in young children's use of external cognitive strategies.

A cardinal feature of adult cognition is the awareness of our own cognitive struggles and the capacity to draw upon this awareness to offload internal demand into the environment. In this preregistered study conducted in Australia, we investigated whether 3-8-year-olds (N = 72, 36 male, 36 female, mostly White) could self-initiate such an external metacognitive strategy and transfer it across contexts. Children watched as an experimenter demonstrated how to mark the location of a hidden prize, thus helping them successfully retrieve that prize in the future. Children were then given the opportunity to spontaneously adopt an external marking strategy across six test trials. Children who did so at least once were then introduced to a conceptually similar but structurally distinct transfer task. Although most 3-year-olds deployed the demonstrated strategy in the initial test phase, none of them modified that strategy to solve the transfer task. By contrast, many children aged 4 years and older spontaneously devised more than one previously unseen reminder-setting strategy across the six transfer trials, with this tendency increasing with age. From age 6, children deployed effective external strategies on most trials, with the number, combination, and order of unique strategies used varying widely both within and across the older age groups. These results demonstrate young children's remarkable flexibility in the transferral of external strategies across contexts and point to pronounced individual differences in the strategies children devise. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Use of Augmentative Interspecies Communication devices in animal language studies: A review.

Countless discussions have been generated by the animal language studies, specifically those utilizing mechanical interfaces, termed here Augmentative Interspecies Communication (AIC) devices (e.g., lexigrams; magnetic chips; keyboards). Overall, three concerns dominate the field: (1) claims that AIC device using animals manifest linguistic skills remain nebulous, and simpler alternative mechanisms have been proposed (e.g., associative learning); (2) such methodology may be unsuitable as some theorize AIC device interfaces are not sufficiently ecologically relevant to foster meaningful use; (3) data may be considered dubious due to potential cueing from experimenters and lack of systematicity in reporting training and performance. Despite such controversy-which eventually led to the field's deterioration around the last quarter of the twentieth century-this research also saw important successes, such as improvements in captive animal welfare, the outcomes of which hold promise for future interspecies communication work. This article is categorized under: Linguistics > Evolution of Language.

Contrafreeloading in kea (Nestor notabilis) in comparison to Grey parrots (Psittacus erithacus).

Contrafreeloading-working to access food that could be freely obtained-is rarely exhibited and poorly understood. Based on data from Grey parrots (Psittacus erithacus), researchers proposed a correlation between contrafreeloading and play: that contrafreeloading is more likely when subjects view the task as play. We tested that hypothesis by subjecting a relatively more playful parrot species, the kea (Nestor notabilis), to the same experimental tasks. Experiment 1 presented eight kea with container pairs holding more- or less-preferred free or enclosed food items, and examined three types of contrafreeloading: calculated (working to access preferred food over less-preferred, freely available food); classic (working to access food identical to freely available food); and super (working to access less-preferred food over preferred, freely available food). At the group level, the kea behaved similarly to the Greys: They significantly preferred calculated contrafreeloading, performed classic contrafreeloading at chance, and significantly failed to super contrafreeload. However, overall kea engaged in more contrafreeloading than Greys. Experiment 2 examined a potentially more ecologically relevant task, a choice between shelled and unshelled walnuts. No kea contrafreeloaded for nuts, whereas two of five Greys significantly preferred nut contrafreeloading and one chose at chance. We examine proximate and adaptive explanations for the performances of these differentially playful parrot species to further elucidate the role of play in contrafreeloading.

The signature-testing approach to mapping biological and artificial intelligences.

Making inferences from behaviour to cognition is problematic due to a many-to-one mapping problem, in which any one behaviour can be generated by multiple possible cognitive processes. Attempts to cross this inferential gap when comparing human intelligence to that of animals or machines can generate great debate. Here, we discuss the challenges of making comparisons using 'success-testing' approaches and call attention to an alternate experimental framework, the 'signature-testing' approach. Signature testing places the search for information-processing errors, biases, and other patterns centre stage, rather than focussing predominantly on problem-solving success. We highlight current research on both biological and artificial intelligence that fits within this framework and is creating proactive research programs that make strong inferences about the similarities and differences between the content of human, animal, and machine minds.

Are parrots naive realists? Kea behave as if the real and virtual worlds are continuous.

Human psychology and animal cognition have increasingly used virtual stimuli to test cognitive abilities, with the expectation that participants are 'naive realists', that is, that they perceive virtual environments as both equivalent and continuous with real-life equivalents. However, there have been no attempts to investigate whether nonhuman subjects in fact behave as if physical processes in the virtual and real worlds are continuous. As kea parrots have previously shown the ability to transfer knowledge between real stimuli and both images on paper and images on touchscreens, here we test whether kea behave as naive realists and so expect physical processes to be continuous between the physical and virtual worlds. We find that, unlike infants, kea do not discriminate between these two contexts, and that they do not exhibit a preference for either. Our findings therefore validate the use of virtual stimuli as a powerful tool for testing the cognition of nonhuman animal species.

Self-care tooling innovation in a disabled kea (Nestor notabilis).

Tooling is associated with complex cognitive abilities, occurring most regularly in large-brained mammals and birds. Among birds, self-care tooling is seemingly rare in the wild, despite several anecdotal reports of this behaviour in captive parrots. Here, we show that Bruce, a disabled parrot lacking his top mandible, deliberately uses pebbles to preen himself. Evidence for this behaviour comes from five lines of evidence: (i) in over 90% of instances where Bruce picked up a pebble, he then used it to preen; (ii) in 95% of instances where Bruce dropped a pebble, he retrieved this pebble, or replaced it, in order to resume preening; (iii) Bruce selected pebbles of a specific size for preening rather than randomly sampling available pebbles in his environment; (iv) no other kea in his environment used pebbles for preening; and (v) when other individuals did interact with stones, they used stones of different sizes to those Bruce preened with. Our study provides novel and empirical evidence for deliberate self-care tooling in a bird species where tooling is not a species-specific behaviour. It also supports claims that tooling can be innovated based on ecological necessity by species with sufficiently domain-general cognition.

Kea (Nestor notabilis) fail a loose-string connectivity task.

Naïve individuals of some bird species can rapidly solve vertical string-pulling tasks with virtually no errors. This has led to various hypotheses being proposed which suggest that birds mentally simulate the effects of their actions on strings. A competing embodied cognition hypothesis proposes that this behaviour is instead modulated by perceptual-motor feedback loops, where feedback of the reward moving closer acts as an internal motivator for functional behaviours, such as pull-stepping. To date, the kea parrot has produced some of the best performances of any bird species at string-pulling tasks. Here, we tested the predictions of the four leading hypotheses for the cognition underpinning bird string-pulling by presenting kea with a horizontal connectivity task where only one of two loose strings was connected to the reward, both before and after receiving perceptual-motor feedback experience. We find that kea fail the connectivity task both before and after perceptual-motor feedback experience, suggesting not only that kea do not mentally simulate their string-pulling actions, but also that perceptual-motor feedback alone is insufficient in eliciting successful performance in the horizontal connectivity task. This suggests a more complex interplay of cognitive factors underlies this iconic example of animal problem-solving.

Dogs Mentally Represent Jealousy-Inducing Social Interactions.

Jealousy may have evolved to protect valuable social bonds from interlopers, but some researchers have suggested that it is linked to self-awareness and theory of mind, leading to claims that it is unique to humans. We presented dogs (N = 18; 11 females; age: M = 4.6 years, SD = 1.9) with situations in which they could observe an out-of-sight social interaction between their owner and a fake dog or between their owner and a fleece cylinder. We found evidence for three signatures of jealous behavior in dogs: (a) Jealousy emerged only when the dog's owner interacted with a perceived social rival, (b) it occurred as a consequence of that interaction and not because of the mere presence of a conspecific, and (c) it emerged even for an out-of-sight interaction between the dog's owner and a social rival. These results support claims that dogs display jealous behavior, and they provide the first evidence that dogs can mentally represent jealousy-inducing social interactions.

Macphail's Null Hypothesis of Vertebrate Intelligence: Insights From Avian Cognition.

Macphail famously criticized two foundational assumptions that underlie the evolutionary approach to comparative psychology: that there are differences in intelligence across species, and that intelligent behavior in animals is based on more than associative learning. Here, we provide evidence from recent work in avian cognition that supports both these assumptions: intelligence across species varies, and animals can perform intelligent behaviors that are not guided solely by associative learning mechanisms. Finally, we reflect on the limitations of comparative psychology that led to Macphail's claims and suggest strategies researchers can use to make more advances in the field.

Kea show three signatures of domain-general statistical inference.

One key aspect of domain-general thought is the ability to integrate information across different cognitive domains. Here, we tested whether kea (Nestor notabilis) can use relative quantities when predicting sampling outcomes, and then integrate both physical information about the presence of a barrier, and social information about the biased sampling of an experimenter, into their predictions. Our results show that kea exhibit three signatures of statistical inference, and therefore can integrate knowledge across different cognitive domains to flexibly adjust their predictions of sampling events. This result provides evidence that true statistical inference is found outside of the great apes, and that aspects of domain-general thinking can convergently evolve in brains with a highly different structure from primates. This has important implications not only for our understanding of how intelligence evolves, but also for research focused on how to create artificial domain-general thought processes.

Contagious yawning is not a signal of empathy: no evidence of familiarity, gender or prosociality biases in dogs.

Contagious yawning has been suggested to be a potential signal of empathy in non-human animals. However, few studies have been able to robustly test this claim. Here, we ran a Bayesian multilevel reanalysis of six studies of contagious yawning in dogs. This provided robust support for claims that contagious yawning is present in dogs, but found no evidence that dogs display either a familiarity or gender bias in contagious yawning, two predictions made by the contagious yawning-empathy hypothesis. Furthermore, in an experiment testing the prosociality bias, a novel prediction of the contagious yawning-empathy hypothesis, dogs did not yawn more in response to a prosocial demonstrator than to an antisocial demonstrator. As such, these strands of evidence suggest that contagious yawning, although present in dogs, is not mediated by empathetic mechanisms. This calls into question claims that contagious yawning is a signal of empathy in mammals.

Watching eyes do not stop dogs stealing food: evidence against a general risk-aversion hypothesis for the watching-eye effect.

The presence of pictures of eyes reduces antisocial behaviour in humans. It has been suggested that this 'watching-eye' effect is the result of a uniquely human sensitivity to reputation-management cues. However, an alternative explanation is that humans are less likely to carry out risky behaviour in general when they feel like they are being watched. This risk-aversion hypothesis predicts that other animals should also show the watching-eye effect because many animals behave more cautiously when being observed. Dogs are an ideal species to test between these hypotheses because they behave in a risk-averse manner when being watched and attend specifically to eyes when assessing humans' attentional states. Here, we examined if dogs were slower to steal food in the presence of pictures of eyes compared to flowers. Dogs showed no difference in the latency to steal food between the two conditions. This finding shows that dogs are not sensitive to watching-eyes and is not consistent with a risk-aversion hypothesis for the watching-eye effect.

Kea (Nestor notabilis) represent object trajectory and identity.

The ability to represent both the identity and trajectory of hidden objects underlies our capacity to reason about causal mechanisms. However, to date no studies have shown that non-human animals are capable of representing these two factors simultaneously. Here, we tested whether kea can represent out-of-sight object trajectories and identities by presenting subjects with three tasks, each of which involved tracking or predicting hand trajectories as they moved behind a screen. Taken together, our results suggest that kea have the capacity for mental simulation in complex tasks involving moving hidden objects.