Large-scale phylogenetic studies of animal cognition have revealed robust links between 6 absolute brain volume and species differences in executive function. However, past comparative 7 samples have been composed largely of primates, which are characterized by evolutionarily 8 derived neural scaling rules. Therefore, it is currently unknown whether positive associations 9 between brain volume and executive function reflect a broad-scale evolutionary phenomenon, or 10 alternatively, a unique consequence of primate brain evolution. Domestic dogs provide a powerful 11 opportunity for investigating this question due to their close genetic relatedness, but vast 12 intraspecific variation. Using citizen science data on more than 7,000 purebred dogs from 74 13 breeds, and controlling for genetic relatedness between breeds, we identify strong relationships 14 between estimated absolute brain weight and breed differences in cognition. Specifically, largerbrained breeds performed significantly better on measures of short-term memory and self-control. However, the relationships between estimated brain weight and other cognitive measures varied widely, supporting domain-specific accounts of cognitive evolution. Our results suggest that evolutionary increases in brain size are positively associated with taxonomic differences in executive function, even in the absence of primate-like neuroanatomy. These findings also suggest that variation between dog breeds may present a powerful model for investigating correlated changes in neuroanatomy and cognition among closely related taxa.

No abstract

No abstract

No abstract

No abstract

Early-emerging and highly heritable sensitivity to human communication in dogsHighlights d Dogs exhibit social skills and interest in human faces by 8 weeks of age d Genetic factors account for nearly half of variation in dog social skills d Puppies successfully used human gestures from the very first trial Authors

Non-human primates can often predict how another agent will behave based on that agent's knowledge about the world. But how do non-human primates represent others' knowledge states? Researchers have recently proposed that non-human primates form "awareness relations" to attribute objectively true information to other minds, as opposed to human-like representations that track others' ignorance or false belief states. We present the first explicit test of the awareness relations hypothesis by examining when rhesus macaques' understanding of other agents' knowledge falters. In Experiment 1, monkeys watched an agent observe a piece of fruit (the target object) being hidden in one of two boxes. While the agent's view was occluded, either the fruit moved out of its box and directly back into it, or the box containing the fruit opened and immediately closed. We found that monkeys looked significantly longer when the agent reached incorrectly rather than correctly after the box's movement, but not after the fruit's movement. This result suggests that monkeys did not expect the agent to know the fruit's location when it briefly and arbitrarily moved while the agent could not see it, but did expect the agent to know the fruit's location when only the box moved while the agent could not see it. In Experiment 2, we replicated and extended both findings with a larger sample, a different target object, and opposite directions of motion in the test trials. These findings suggest that monkeys reason about others' knowledge of objects by forming awareness relations which are disrupted by arbitrary spatial manipulation of the target object while an agent has no perceptual access to it.

No abstract