This study examined whether miniature pigs could discriminate people based on their photographs. In experiment 1, the pigs were trained to discriminate between two people in the Y maze. All pigs successfully discriminated between the persons. The pigs were then tested with photographs of those same people, but no pigs discriminated between the photographs. In experiment 2, three pigs were trained to discriminate between photographs of people. Then they were tested to determine whether they could discriminate the same people. Some pigs appeared to discriminate between one pair of people but not the other pairs. In experiment 3, four pigs were used to test whether they had learned to discriminate between photographs of people learned more quickly to discriminate them than pigs that had learned to discriminate between two-dimensional abstract figures. The number of sessions to discriminate between people was not affected by the treatment. Results show that pigs can learn to discriminate between people and between photographs of people, but they had difficulty in discriminating the people based on their photographs.

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One rat was trained to respond to two four-item-series, A1-B1-C1-D1 and A2-B2-C2-D2, concurrently by responding to four barriers of modified Hill maze in a fixed order. Two types of novel series in which items were exchanged between the two original series were inserted to training as test series. In the congruent test series items that had same serial positions were exchanged between series (e.g., A1-B2-C1-D1, A2-B2-C1-D2), whereas in the incongruent test series items of different serial positions were exchanged (e.g., A1-C2-C1-D1, A2-B2-B1-D2). Rats showed reliably better performance to the congruent test series than the incongruent test series. The item association learning cannot explain this result because the same number of new item associations between exchanged items and adjacent items should be required in the congruent and the incongruent series. Therefore present findings strongly suggest that rats can learn serial position of item B and C of a four-item-series in a certain kind of serial learning procedure.

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Animal models of human behavioral or cognitive processes are essential for studying mechanisms of these processes. A choice reaction time task was developed for assessing sustained attention in rats; a previous study showed that rats perform the task as predicted from other sustained attention tasks in rats and humans. In this study, we measured the behavior of humans in a choice reaction time task procedurally matched to the task for rats, and examined the effect of decreasing the presentation rate of stimulus through prolonging the inter-trial intervals, which was previously shown to affect performance in rats. As in rats, choice reaction speed decreased and omission errors increased as the decrease of presentation rate of stimulus. These data showed that choice reaction time behavior both in rats and humans was controlled similarly by the parameter, which suggests that this task assesses similar processes of sustained attention in the two species.

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Do humans and nonhumans share numerical and perceptual abilities? Some researchers argue that nonhumans, lacking human language, possess exact understanding only of quantities up to about 4. Animals trained in human communication systems might, however, be more advanced. ALEX, a Grey parrot, could, for example, quantify sets of ≤8 items (including heterogeneous subsets) using vocal English labels, comprehend these labels fully, sum small quantities, and had a zero-like concept. He understood number symbols as abstract representations of real-world collections, in ways comparing favorably to those of apes and young human children. He appeared to learn in ways more similar to humans than apes.

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This study surveys dairy farmers' ways of raising, sense of animal welfare, and emotional impressions on their cows, and discusses their personification to livestock in contrast with that to companion animals. The farmers have professional knowledge and skills to feed and handle the cows. They get a living from keeping cows, considering the cost and benefit. This economy-based view sometimes leads to the desertion of treatment on disordered livestock. Companion animal owners usually keep their animals with no such economy-based but emotion-based view. Farmers' “employer-employee” relationship to their cows would interfere with the personification attitudes. This author compared the attitudes of 187 dairy farmers and 218 collage students, reveals the dairy farmers show more sensitivity to animal welfare and more favorable impression and stronger personification, such as “child-like” and “family-like” views. Thus emotion-based attitudes and the personification would be caused in any situations with human-animal interactions, regardless of the roles and the professional knowledge of animals. As a calming effect of handling for experimental animals and decreased escape distance on intimately reared cows show, animals interacted with human also have the emotion-based affection or emotional bond.

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Anthropomorphim is an enduring controversy in comparative cognition. Some studies in comparative cognition search for human-like behavior as evidence for evolutionary continuity of mental processes as Darwin encouraged. Others eschew interpreting observed behaviors in terms of anthropomorphic mental processes. Even in the former cases, students of comparative cognition often use the predictions by associative learning or reinforcement learning as killjoy explanations to examine the existence of complex cognitive processes shared between humans and other species. In the present paper, I reviewed some of such challenges, including my own, to show how anthropomorphic questions can be studied scientifically. I also reviewed other studies in which the killjoy explanations were inappropriately applied. Misuses of the killjoy explanations are typically revealed by showing human adults behave differently from the experimenters anthropomorphic predictions.

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Many researchers have been interested in cognitive abilities of animals and investigated those issues by using several methods. Associative learning theory, which is mainly adopted in classical and operant conditioning literature, has been considered “simple” and sometime “appropriate” account of animal behavior from the point of view of Morgan's canon. In present article, criticism toward associative account and another reason why associative account is appropriate for animal behavior were reviewed, proposing proper usage of associative learning theory in complex animal behavior. One possible answer in present discussion is that associative learning theory is some kind of “intermediate language”, which can work as the bridge among neural mechanism, psychological faculty in animals, and anthropomorphic explanations.

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Comparative behavioural research in canines may have the potential to add a new impetus for cognitive research on animals and humans. However this is a very young area that needs also re-thinking of old problems and questions which have been around for a long time. In this short essay we tackle three partially related problems: (1) interpretation of behavioural differences in dogs and wolves, (2) the idea of co-evolution of dogs and humans, and (3) issues of theory of mind.
We present a simple synergic model that takes both genetic and environmental factors into account in order to provide a balanced picture on the effect of domestication on dog behaviour, and how human social environment affects dog and wolf behaviour development. In the absence of evidence we argue against dog-human co-evolution in biological terms, leaving open the possibility for co-evolution at the cultural level. Finally, we suggest that the utilisation of complex cognitive models, such as theory of mind, is questionable, and actually more confusing in present day research on dogs' sociocognitive skills.

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Various studies have shown the associations between individual differences in human behavioral traits and genetic polymorphism of neurotransmitter-related proteins such as receptor, transporter and monoamine oxidase. To insight the genetic background of animal behavior, corresponding regions in animals have been analyzed. Especially the study has been promoted in dogs as the socially closest animal to humans. In dogs allele distributions of several genes were different among breeds showing different behavioral traits, and genes associating individual difference in aggressiveness and aptitude of working dogs were surveyed. The survey of behavior-related genes is also carried out in other mammals such as primates, horses and cetaceans and also in birds. The marker genes for behavior will provide useful information for better relationship with companion dogs and effective selection of working dogs.

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Dogs have been domesticated by humans for more than 15,000 years. Now, dogs are the most closely related animals to humans in the world. Behind this evolutional process, the rare ability of dog's social cognition and to read human emotions and situations have been pointed out. The superior cognitive ability of dogs have achieved a unique niche in the human society, also nowadays its cognitive and learning ability has become a valuable research topic in the research field of animal psychology. Recent studies of human and dog suggest that these two species have been developed in the convergent evolution, on the process of domestication. So our best friend “dog” is not just domesticated animals, a “companion” who live together within human society as a unique species. This paper introduces some specific social skills of dogs and its biological properties, which have been revealed by molecular biological and cognitive science approaches in recent years.

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