Ravens parallel great apes in physical and social cognitive skills

Simone Pika,Christian R Blum,Roger Mundry,Esther Herrmann,Miriam Jennifer Sima

doi:10.1038/s41598-020-77060-8

Abstract

Human children show unique cognitive skills for dealing with the social world but their cognitive performance is paralleled by great apes in many tasks dealing with the physical world. Recent studies suggested that members of a songbird family—corvids—also evolved complex cognitive skills but a detailed understanding of the full scope of their cognition was, until now, not existent. Furthermore, relatively little is known about their cognitive development. Here, we conducted the first systematic, quantitative large-scale assessment of physical and social cognitive performance of common ravens with a special focus on development. To do so, we fine-tuned one of the most comprehensive experimental test-batteries, the Primate Cognition Test Battery (PCTB), to raven features enabling also a direct, quantitative comparison with the cognitive performance of two great ape species. Full-blown cognitive skills were already present at the age of four months with subadult ravens’ cognitive performance appearing very similar to that of adult apes in tasks of physical (quantities, and causality) and social cognition (social learning, communication, and theory of mind). These unprecedented findings strengthen recent assessments of ravens’ general intelligence, and aid to the growing evidence that the lack of a specific cortical architecture does not hinder advanced cognitive skills. Difficulties in certain cognitive scales further emphasize the quest to develop comparative test batteries that tap into true species rather than human specific cognitive skills, and suggest that socialization of test individuals may play a crucial role. We conclude to pay more attention to the impact of personality on cognitive output, and a currently neglected topic in Animal Cognition—the linkage between ontogeny and cognitive performance.

Highlights

Cognitive path, involving a species-specific set of social-cognitive skills for participating and exchanging knowledge in cultural groups[10]
It has been suggested that crucial developments in skills of human social-cultural cognition may have occurred only post-erectus, in support of especially complex forms of collaborative activity, such as hunting or gathering, supported by special skills of communication and social learning[13]. These abilities possibly developed from earlier evolved primate skills of social cognition, communication and learning in general that nonhuman primates display in their everyday interactions to cope with the challenges of their social environments[14,15,16,17]
Predominant theories propose that the distinctive aspects of primate cognition evolved mainly in response to the cognitive challenges of the ecological environment, or the challenges of the social environment including the need to form and maintain social bonds, cooperation, track third-party relationships, and anticipate the behaviour of conspecifics

Summary

Introduction

Cognitive path, involving a species-specific set of social-cognitive skills for participating and exchanging knowledge in cultural groups[10]. The Social Intelligence hypothesis was originally applied to non-human primates only[14], the idea has recently inspired a lot of research studies in other taxa showing sophisticated social relationships and/ or long-term bonds (e.g.31,32). European jays (Garrulus glandarius), magpies (Pica pica) and common ravens begin to store and retrieve their caches around the time of feeding independence and acquire sophisticated levels of object permanence (up to stage 6 in European jays and ravens) in their first year of life[66,67,68] This rapid developmental phase stands in stark contrast to the much slower developmental pace in different species of psittacines[69,70], which are renowned for their sophisticated cognitive skills (e.g.,49,71). Divergent patterns of cognitive development were apparent in the social domain, including for instance greater inter-relationships of social cognitive skills in children relative to apes (see [75])

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Conclusion